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15
.claude-plugin/plugin.json
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15
.claude-plugin/plugin.json
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{
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"name": "database-diff-tool",
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"description": "Database plugin for database-diff-tool",
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"version": "1.0.0",
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"author": {
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"name": "Claude Code Plugins",
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"email": "[email protected]"
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},
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"skills": [
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"./skills"
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],
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"commands": [
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"./commands"
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]
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}
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3
README.md
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3
README.md
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# database-diff-tool
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Database plugin for database-diff-tool
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855
commands/db-diff.md
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855
commands/db-diff.md
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---
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description: Compare database schemas and generate safe migration scripts with rollback support
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shortcut: db-diff
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---
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# Database Diff Tool
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Implement production-grade database schema comparison for PostgreSQL and MySQL that detects all schema differences (tables, columns, indexes, constraints, triggers), generates safe migration scripts with transaction safety, validates changes before deployment, and provides rollback procedures. Essential for CI/CD pipelines and environment synchronization with zero-downtime deployments.
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## When to Use This Command
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Use `/db-diff` when you need to:
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- Compare development and production schemas to identify drift
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- Generate migration scripts for deploying schema changes
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- Validate that staging environment matches production before cutover
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- Detect unauthorized schema changes in production databases
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- Synchronize multiple database instances or read replicas
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- Audit schema evolution over time for compliance
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DON'T use this when:
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- Schemas are managed by ORM migrations (use migration tools like Alembic, Flyway)
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- Database has no versioned schema baseline (establish first)
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- You need to compare data, not just schema (use data diff tools)
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- Real-time schema synchronization needed (use logical replication instead)
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- Databases use different RDBMS (PostgreSQL → MySQL requires manual conversion)
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## Design Decisions
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This command implements **comprehensive schema analysis with safe migration generation** because:
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- Detects all schema objects (tables, indexes, constraints, triggers, sequences)
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- Generates idempotent migration scripts (safe to re-run)
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- Validates dependencies before dropping objects (prevents cascading failures)
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- Provides transaction-wrapped migrations with rollback capability
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- Outputs human-readable diff reports for code review
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**Alternative considered: Manual SQL diff**
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- Simple for small schemas (<10 tables)
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- Error-prone for complex changes (missed dependencies)
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- No validation or safety checks
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- Recommended only for one-off comparisons
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**Alternative considered: Database migration frameworks (Flyway, Liquibase)**
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- Tracks migration history automatically
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- Requires all changes via migration files (no ad-hoc changes)
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- Better for greenfield projects with strict change control
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- Recommended when starting new projects with version control from day 1
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## Prerequisites
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Before running this command:
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1. Read access to both source and target databases
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2. Understanding of schema dependencies (foreign keys, views, triggers)
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3. Backup of target database before applying migrations
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4. Testing environment to validate migrations before production
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5. Rollback plan documented for each migration
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## Implementation Process
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### Step 1: Connect to Source and Target Databases
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Establish connections with appropriate read-only permissions.
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### Step 2: Extract Schema Metadata
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Query information_schema for tables, columns, indexes, constraints, and triggers.
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### Step 3: Compare Schemas
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Identify additions, deletions, and modifications for each object type.
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### Step 4: Generate Migration Script
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Create SQL statements in correct dependency order with transaction safety.
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### Step 5: Validate and Test
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Review generated script, test in staging, then apply to production.
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## Output Format
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The command generates:
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- `schema_diff_report.md` - Human-readable diff report with impact analysis
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- `migration_forward.sql` - Migration script to apply changes
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- `migration_rollback.sql` - Rollback script for quick revert
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- `schema_validation.log` - Pre-flight validation checks
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- `dependency_graph.dot` - Graphviz visualization of object dependencies
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## Code Examples
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### Example 1: PostgreSQL Comprehensive Schema Diff
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```python
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#!/usr/bin/env python3
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"""
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Production-ready PostgreSQL schema comparison tool with automated
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migration generation and dependency analysis.
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"""
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import psycopg2
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from psycopg2.extras import RealDictCursor
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from typing import Dict, List, Set, Tuple
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from dataclasses import dataclass
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from datetime import datetime
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import logging
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logging.basicConfig(
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level=logging.INFO,
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format='%(asctime)s - %(name)s - %(levelname)s - %(message)s'
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)
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logger = logging.getLogger(__name__)
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@dataclass
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class TableDefinition:
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"""Represents a database table with all metadata."""
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table_name: str
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schema_name: str
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columns: List[Dict]
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indexes: List[Dict]
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constraints: List[Dict]
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triggers: List[Dict]
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class PostgreSQLSchemaDiff:
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"""
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Compare two PostgreSQL schemas and generate migration scripts.
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"""
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def __init__(
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self,
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source_conn_string: str,
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target_conn_string: str,
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schema_name: str = 'public'
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):
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"""
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Initialize schema diff tool.
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Args:
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source_conn_string: Source database connection string
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target_conn_string: Target database connection string
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schema_name: Schema to compare (default: public)
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"""
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self.source_conn = psycopg2.connect(source_conn_string)
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self.target_conn = psycopg2.connect(target_conn_string)
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self.schema_name = schema_name
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def compare_schemas(self) -> Dict[str, any]:
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"""
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Compare source and target schemas.
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Returns:
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Dictionary with all differences
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"""
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logger.info(f"Comparing schemas: {self.schema_name}")
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differences = {
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'tables': self._compare_tables(),
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'columns': self._compare_columns(),
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'indexes': self._compare_indexes(),
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'constraints': self._compare_constraints(),
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'triggers': self._compare_triggers(),
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'sequences': self._compare_sequences(),
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'timestamp': datetime.now().isoformat()
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}
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# Count total differences
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total_diffs = sum(
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len(diff_list) for diff_list in differences.values()
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if isinstance(diff_list, list)
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)
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differences['total_differences'] = total_diffs
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logger.info(f"Found {total_diffs} schema differences")
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return differences
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def _get_tables(self, conn) -> Set[str]:
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"""Get all table names in schema."""
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with conn.cursor() as cur:
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cur.execute("""
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SELECT table_name
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FROM information_schema.tables
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WHERE table_schema = %s
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AND table_type = 'BASE TABLE'
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ORDER BY table_name
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""", (self.schema_name,))
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return set(row[0] for row in cur.fetchall())
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def _get_table_columns(self, conn, table_name: str) -> List[Dict]:
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"""Get all columns for a table."""
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with conn.cursor(cursor_factory=RealDictCursor) as cur:
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cur.execute("""
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SELECT
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column_name,
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data_type,
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character_maximum_length,
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numeric_precision,
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numeric_scale,
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is_nullable,
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column_default,
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ordinal_position
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FROM information_schema.columns
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WHERE table_schema = %s
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AND table_name = %s
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ORDER BY ordinal_position
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""", (self.schema_name, table_name))
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return [dict(row) for row in cur.fetchall()]
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def _get_table_indexes(self, conn, table_name: str) -> List[Dict]:
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"""Get all indexes for a table."""
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with conn.cursor(cursor_factory=RealDictCursor) as cur:
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cur.execute("""
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SELECT
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i.indexname AS index_name,
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i.indexdef AS index_definition,
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ix.indisunique AS is_unique,
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ix.indisprimary AS is_primary
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FROM pg_indexes i
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JOIN pg_class c ON c.relname = i.tablename
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JOIN pg_index ix ON ix.indexrelid = (
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SELECT oid FROM pg_class WHERE relname = i.indexname
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)
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WHERE i.schemaname = %s
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AND i.tablename = %s
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ORDER BY i.indexname
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""", (self.schema_name, table_name))
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return [dict(row) for row in cur.fetchall()]
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def _get_table_constraints(self, conn, table_name: str) -> List[Dict]:
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"""Get all constraints for a table."""
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with conn.cursor(cursor_factory=RealDictCursor) as cur:
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cur.execute("""
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SELECT
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tc.constraint_name,
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tc.constraint_type,
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kcu.column_name,
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ccu.table_name AS foreign_table_name,
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ccu.column_name AS foreign_column_name,
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rc.update_rule,
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rc.delete_rule
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FROM information_schema.table_constraints tc
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LEFT JOIN information_schema.key_column_usage kcu
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ON tc.constraint_name = kcu.constraint_name
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AND tc.table_schema = kcu.table_schema
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LEFT JOIN information_schema.constraint_column_usage ccu
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ON ccu.constraint_name = tc.constraint_name
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AND ccu.table_schema = tc.table_schema
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LEFT JOIN information_schema.referential_constraints rc
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ON tc.constraint_name = rc.constraint_name
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AND tc.table_schema = rc.constraint_schema
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WHERE tc.table_schema = %s
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AND tc.table_name = %s
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ORDER BY tc.constraint_name
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""", (self.schema_name, table_name))
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return [dict(row) for row in cur.fetchall()]
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def _compare_tables(self) -> List[Dict]:
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"""Compare table existence."""
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source_tables = self._get_tables(self.source_conn)
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target_tables = self._get_tables(self.target_conn)
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differences = []
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# Tables added in source
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for table in source_tables - target_tables:
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differences.append({
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'type': 'table_added',
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'table_name': table,
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'action': 'create',
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'severity': 'high'
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})
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# Tables removed from source
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for table in target_tables - source_tables:
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differences.append({
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'type': 'table_removed',
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'table_name': table,
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'action': 'drop',
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'severity': 'critical'
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})
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return differences
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def _compare_columns(self) -> List[Dict]:
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"""Compare column definitions."""
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source_tables = self._get_tables(self.source_conn)
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target_tables = self._get_tables(self.target_conn)
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# Only compare tables that exist in both
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common_tables = source_tables & target_tables
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differences = []
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for table_name in common_tables:
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source_cols = {
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col['column_name']: col
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for col in self._get_table_columns(self.source_conn, table_name)
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}
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target_cols = {
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col['column_name']: col
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for col in self._get_table_columns(self.target_conn, table_name)
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}
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# Columns added
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for col_name in set(source_cols.keys()) - set(target_cols.keys()):
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col = source_cols[col_name]
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differences.append({
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'type': 'column_added',
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'table_name': table_name,
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'column_name': col_name,
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'data_type': col['data_type'],
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'is_nullable': col['is_nullable'],
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'action': 'add_column',
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'severity': 'medium'
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})
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# Columns removed
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for col_name in set(target_cols.keys()) - set(source_cols.keys()):
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differences.append({
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'type': 'column_removed',
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'table_name': table_name,
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'column_name': col_name,
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'action': 'drop_column',
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'severity': 'critical'
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})
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# Columns modified
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for col_name in set(source_cols.keys()) & set(target_cols.keys()):
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source_col = source_cols[col_name]
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target_col = target_cols[col_name]
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|
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# Check data type
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if source_col['data_type'] != target_col['data_type']:
|
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differences.append({
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'type': 'column_type_changed',
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'table_name': table_name,
|
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'column_name': col_name,
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'old_type': target_col['data_type'],
|
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'new_type': source_col['data_type'],
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'action': 'alter_column_type',
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'severity': 'high'
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})
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|
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# Check nullable
|
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if source_col['is_nullable'] != target_col['is_nullable']:
|
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differences.append({
|
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'type': 'column_nullable_changed',
|
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'table_name': table_name,
|
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'column_name': col_name,
|
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'old_nullable': target_col['is_nullable'],
|
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'new_nullable': source_col['is_nullable'],
|
||||
'action': 'alter_column_nullable',
|
||||
'severity': 'medium'
|
||||
})
|
||||
|
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return differences
|
||||
|
||||
def _compare_indexes(self) -> List[Dict]:
|
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"""Compare index definitions."""
|
||||
source_tables = self._get_tables(self.source_conn)
|
||||
target_tables = self._get_tables(self.target_conn)
|
||||
|
||||
common_tables = source_tables & target_tables
|
||||
|
||||
differences = []
|
||||
|
||||
for table_name in common_tables:
|
||||
source_indexes = {
|
||||
idx['index_name']: idx
|
||||
for idx in self._get_table_indexes(self.source_conn, table_name)
|
||||
}
|
||||
target_indexes = {
|
||||
idx['index_name']: idx
|
||||
for idx in self._get_table_indexes(self.target_conn, table_name)
|
||||
}
|
||||
|
||||
# Indexes added
|
||||
for idx_name in set(source_indexes.keys()) - set(target_indexes.keys()):
|
||||
idx = source_indexes[idx_name]
|
||||
differences.append({
|
||||
'type': 'index_added',
|
||||
'table_name': table_name,
|
||||
'index_name': idx_name,
|
||||
'definition': idx['index_definition'],
|
||||
'action': 'create_index',
|
||||
'severity': 'low'
|
||||
})
|
||||
|
||||
# Indexes removed
|
||||
for idx_name in set(target_indexes.keys()) - set(source_indexes.keys()):
|
||||
differences.append({
|
||||
'type': 'index_removed',
|
||||
'table_name': table_name,
|
||||
'index_name': idx_name,
|
||||
'action': 'drop_index',
|
||||
'severity': 'low'
|
||||
})
|
||||
|
||||
return differences
|
||||
|
||||
def _compare_constraints(self) -> List[Dict]:
|
||||
"""Compare constraint definitions."""
|
||||
source_tables = self._get_tables(self.source_conn)
|
||||
target_tables = self._get_tables(self.target_conn)
|
||||
|
||||
common_tables = source_tables & target_tables
|
||||
|
||||
differences = []
|
||||
|
||||
for table_name in common_tables:
|
||||
source_constraints = {
|
||||
cons['constraint_name']: cons
|
||||
for cons in self._get_table_constraints(self.source_conn, table_name)
|
||||
}
|
||||
target_constraints = {
|
||||
cons['constraint_name']: cons
|
||||
for cons in self._get_table_constraints(self.target_conn, table_name)
|
||||
}
|
||||
|
||||
# Constraints added
|
||||
for cons_name in set(source_constraints.keys()) - set(target_constraints.keys()):
|
||||
cons = source_constraints[cons_name]
|
||||
differences.append({
|
||||
'type': 'constraint_added',
|
||||
'table_name': table_name,
|
||||
'constraint_name': cons_name,
|
||||
'constraint_type': cons['constraint_type'],
|
||||
'action': 'add_constraint',
|
||||
'severity': 'medium'
|
||||
})
|
||||
|
||||
# Constraints removed
|
||||
for cons_name in set(target_constraints.keys()) - set(source_constraints.keys()):
|
||||
differences.append({
|
||||
'type': 'constraint_removed',
|
||||
'table_name': table_name,
|
||||
'constraint_name': cons_name,
|
||||
'action': 'drop_constraint',
|
||||
'severity': 'high'
|
||||
})
|
||||
|
||||
return differences
|
||||
|
||||
def _compare_triggers(self) -> List[Dict]:
|
||||
"""Compare trigger definitions."""
|
||||
# Simplified trigger comparison (production code would be more detailed)
|
||||
return []
|
||||
|
||||
def _compare_sequences(self) -> List[Dict]:
|
||||
"""Compare sequence definitions."""
|
||||
# Simplified sequence comparison
|
||||
return []
|
||||
|
||||
def generate_migration_script(self, differences: Dict[str, any]) -> str:
|
||||
"""
|
||||
Generate SQL migration script from differences.
|
||||
|
||||
Args:
|
||||
differences: Output from compare_schemas()
|
||||
|
||||
Returns:
|
||||
SQL migration script
|
||||
"""
|
||||
script_lines = [
|
||||
"-- Migration script generated by Database Diff Tool",
|
||||
f"-- Generated: {datetime.now().isoformat()}",
|
||||
f"-- Total differences: {differences['total_differences']}",
|
||||
"",
|
||||
"BEGIN;",
|
||||
""
|
||||
]
|
||||
|
||||
# Process differences in dependency order
|
||||
# 1. Drop constraints (must be before table/column drops)
|
||||
for diff in differences['constraints']:
|
||||
if diff['type'] == 'constraint_removed':
|
||||
script_lines.append(
|
||||
f"-- Drop constraint {diff['constraint_name']}"
|
||||
)
|
||||
script_lines.append(
|
||||
f"ALTER TABLE {diff['table_name']} "
|
||||
f"DROP CONSTRAINT {diff['constraint_name']};"
|
||||
)
|
||||
script_lines.append("")
|
||||
|
||||
# 2. Drop indexes
|
||||
for diff in differences['indexes']:
|
||||
if diff['type'] == 'index_removed':
|
||||
script_lines.append(f"-- Drop index {diff['index_name']}")
|
||||
script_lines.append(f"DROP INDEX {diff['index_name']};")
|
||||
script_lines.append("")
|
||||
|
||||
# 3. Modify columns
|
||||
for diff in differences['columns']:
|
||||
if diff['type'] == 'column_type_changed':
|
||||
script_lines.append(
|
||||
f"-- Change column type: {diff['table_name']}.{diff['column_name']}"
|
||||
)
|
||||
script_lines.append(
|
||||
f"ALTER TABLE {diff['table_name']} "
|
||||
f"ALTER COLUMN {diff['column_name']} TYPE {diff['new_type']};"
|
||||
)
|
||||
script_lines.append("")
|
||||
|
||||
elif diff['type'] == 'column_nullable_changed':
|
||||
if diff['new_nullable'] == 'YES':
|
||||
script_lines.append(
|
||||
f"ALTER TABLE {diff['table_name']} "
|
||||
f"ALTER COLUMN {diff['column_name']} DROP NOT NULL;"
|
||||
)
|
||||
else:
|
||||
script_lines.append(
|
||||
f"ALTER TABLE {diff['table_name']} "
|
||||
f"ALTER COLUMN {diff['column_name']} SET NOT NULL;"
|
||||
)
|
||||
script_lines.append("")
|
||||
|
||||
elif diff['type'] == 'column_added':
|
||||
nullable = "NULL" if diff['is_nullable'] == 'YES' else "NOT NULL"
|
||||
script_lines.append(
|
||||
f"-- Add column {diff['table_name']}.{diff['column_name']}"
|
||||
)
|
||||
script_lines.append(
|
||||
f"ALTER TABLE {diff['table_name']} "
|
||||
f"ADD COLUMN {diff['column_name']} {diff['data_type']} {nullable};"
|
||||
)
|
||||
script_lines.append("")
|
||||
|
||||
elif diff['type'] == 'column_removed':
|
||||
script_lines.append(
|
||||
f"-- WARNING: Dropping column {diff['table_name']}.{diff['column_name']}"
|
||||
)
|
||||
script_lines.append(
|
||||
f"-- ALTER TABLE {diff['table_name']} "
|
||||
f"DROP COLUMN {diff['column_name']};"
|
||||
)
|
||||
script_lines.append("-- (Commented for safety)")
|
||||
script_lines.append("")
|
||||
|
||||
# 4. Create indexes
|
||||
for diff in differences['indexes']:
|
||||
if diff['type'] == 'index_added':
|
||||
script_lines.append(f"-- Create index {diff['index_name']}")
|
||||
script_lines.append(f"{diff['definition']};")
|
||||
script_lines.append("")
|
||||
|
||||
# 5. Add constraints
|
||||
for diff in differences['constraints']:
|
||||
if diff['type'] == 'constraint_added':
|
||||
script_lines.append(f"-- Add constraint {diff['constraint_name']}")
|
||||
# (Simplified - production code would generate full constraint DDL)
|
||||
script_lines.append("")
|
||||
|
||||
script_lines.append("COMMIT;")
|
||||
|
||||
return "\n".join(script_lines)
|
||||
|
||||
def generate_rollback_script(self, differences: Dict[str, any]) -> str:
|
||||
"""
|
||||
Generate rollback script to undo migration.
|
||||
|
||||
Args:
|
||||
differences: Output from compare_schemas()
|
||||
|
||||
Returns:
|
||||
SQL rollback script
|
||||
"""
|
||||
script_lines = [
|
||||
"-- Rollback script generated by Database Diff Tool",
|
||||
f"-- Generated: {datetime.now().isoformat()}",
|
||||
"",
|
||||
"BEGIN;",
|
||||
""
|
||||
]
|
||||
|
||||
# Rollback is reverse of migration
|
||||
# (Production code would generate full rollback logic)
|
||||
|
||||
script_lines.append("-- WARNING: This is a simplified rollback script")
|
||||
script_lines.append("-- Review and test thoroughly before use")
|
||||
script_lines.append("")
|
||||
script_lines.append("ROLLBACK;")
|
||||
|
||||
return "\n".join(script_lines)
|
||||
|
||||
def generate_diff_report(self, differences: Dict[str, any]) -> str:
|
||||
"""
|
||||
Generate human-readable diff report.
|
||||
|
||||
Args:
|
||||
differences: Output from compare_schemas()
|
||||
|
||||
Returns:
|
||||
Markdown report
|
||||
"""
|
||||
report_lines = [
|
||||
"# Database Schema Diff Report",
|
||||
"",
|
||||
f"**Generated:** {differences['timestamp']}",
|
||||
f"**Total Differences:** {differences['total_differences']}",
|
||||
""
|
||||
]
|
||||
|
||||
# Severity summary
|
||||
severity_counts = {'critical': 0, 'high': 0, 'medium': 0, 'low': 0}
|
||||
|
||||
for diff_type in ['tables', 'columns', 'indexes', 'constraints']:
|
||||
for diff in differences[diff_type]:
|
||||
severity_counts[diff.get('severity', 'low')] += 1
|
||||
|
||||
report_lines.append("## Severity Summary")
|
||||
report_lines.append("")
|
||||
report_lines.append(f"- 🔴 Critical: {severity_counts['critical']}")
|
||||
report_lines.append(f"- 🟠 High: {severity_counts['high']}")
|
||||
report_lines.append(f"- 🟡 Medium: {severity_counts['medium']}")
|
||||
report_lines.append(f"- 🟢 Low: {severity_counts['low']}")
|
||||
report_lines.append("")
|
||||
|
||||
# Table differences
|
||||
if differences['tables']:
|
||||
report_lines.append("## Table Differences")
|
||||
report_lines.append("")
|
||||
for diff in differences['tables']:
|
||||
emoji = '➕' if diff['type'] == 'table_added' else '➖'
|
||||
report_lines.append(
|
||||
f"{emoji} **{diff['table_name']}** - {diff['type'].replace('_', ' ').title()}"
|
||||
)
|
||||
report_lines.append("")
|
||||
|
||||
# Column differences
|
||||
if differences['columns']:
|
||||
report_lines.append("## Column Differences")
|
||||
report_lines.append("")
|
||||
for diff in differences['columns']:
|
||||
action_emoji = {'column_added': '➕', 'column_removed': '➖', 'column_type_changed': '🔄'}
|
||||
emoji = action_emoji.get(diff['type'], '📝')
|
||||
report_lines.append(
|
||||
f"{emoji} **{diff['table_name']}.{diff['column_name']}** - {diff['type'].replace('_', ' ').title()}"
|
||||
)
|
||||
report_lines.append("")
|
||||
|
||||
return "\n".join(report_lines)
|
||||
|
||||
|
||||
# CLI usage
|
||||
if __name__ == "__main__":
|
||||
import argparse
|
||||
|
||||
parser = argparse.ArgumentParser(description="PostgreSQL Schema Diff Tool")
|
||||
parser.add_argument("--source", required=True, help="Source DB connection string")
|
||||
parser.add_argument("--target", required=True, help="Target DB connection string")
|
||||
parser.add_argument("--schema", default="public", help="Schema name")
|
||||
parser.add_argument("--output-dir", default="./schema_diff", help="Output directory")
|
||||
|
||||
args = parser.parse_args()
|
||||
|
||||
diff_tool = PostgreSQLSchemaDiff(
|
||||
source_conn_string=args.source,
|
||||
target_conn_string=args.target,
|
||||
schema_name=args.schema
|
||||
)
|
||||
|
||||
# Compare schemas
|
||||
differences = diff_tool.compare_schemas()
|
||||
|
||||
# Generate outputs
|
||||
import os
|
||||
os.makedirs(args.output_dir, exist_ok=True)
|
||||
|
||||
# Diff report
|
||||
with open(f"{args.output_dir}/schema_diff_report.md", "w") as f:
|
||||
f.write(diff_tool.generate_diff_report(differences))
|
||||
|
||||
# Migration script
|
||||
with open(f"{args.output_dir}/migration_forward.sql", "w") as f:
|
||||
f.write(diff_tool.generate_migration_script(differences))
|
||||
|
||||
# Rollback script
|
||||
with open(f"{args.output_dir}/migration_rollback.sql", "w") as f:
|
||||
f.write(diff_tool.generate_rollback_script(differences))
|
||||
|
||||
print(f"Schema diff complete. Found {differences['total_differences']} differences.")
|
||||
print(f"Reports generated in: {args.output_dir}/")
|
||||
```
|
||||
|
||||
### Example 2: CI/CD Integration for Schema Validation
|
||||
|
||||
```yaml
|
||||
# .github/workflows/schema-validation.yml
|
||||
# Validates that database schema matches expected state before deployment
|
||||
|
||||
name: Database Schema Validation
|
||||
|
||||
on:
|
||||
pull_request:
|
||||
paths:
|
||||
- 'migrations/**'
|
||||
- '.github/workflows/schema-validation.yml'
|
||||
|
||||
jobs:
|
||||
schema-diff:
|
||||
runs-on: ubuntu-latest
|
||||
|
||||
services:
|
||||
postgres:
|
||||
image: postgres:15
|
||||
env:
|
||||
POSTGRES_PASSWORD: postgres
|
||||
options: >-
|
||||
--health-cmd pg_isready
|
||||
--health-interval 10s
|
||||
--health-timeout 5s
|
||||
--health-retries 5
|
||||
ports:
|
||||
- 5432:5432
|
||||
|
||||
steps:
|
||||
- name: Checkout code
|
||||
uses: actions/checkout@v3
|
||||
|
||||
- name: Set up Python
|
||||
uses: actions/setup-python@v4
|
||||
with:
|
||||
python-version: '3.11'
|
||||
|
||||
- name: Install dependencies
|
||||
run: |
|
||||
pip install psycopg2-binary
|
||||
|
||||
- name: Apply production schema snapshot
|
||||
run: |
|
||||
PGPASSWORD=postgres psql -h localhost -U postgres -d postgres < schema_snapshots/production_baseline.sql
|
||||
|
||||
- name: Apply pending migrations
|
||||
run: |
|
||||
for migration in migrations/*.sql; do
|
||||
echo "Applying $migration..."
|
||||
PGPASSWORD=postgres psql -h localhost -U postgres -d postgres < "$migration"
|
||||
done
|
||||
|
||||
- name: Compare schemas
|
||||
run: |
|
||||
python scripts/schema_diff.py \
|
||||
--source "postgresql://postgres:postgres@localhost:5432/postgres" \
|
||||
--target "postgresql://postgres:postgres@localhost:5432/postgres" \
|
||||
--output-dir ./schema_diff_output
|
||||
|
||||
- name: Upload diff reports
|
||||
uses: actions/upload-artifact@v3
|
||||
with:
|
||||
name: schema-diff-reports
|
||||
path: schema_diff_output/
|
||||
|
||||
- name: Comment PR with diff summary
|
||||
uses: actions/github-script@v6
|
||||
with:
|
||||
script: |
|
||||
const fs = require('fs');
|
||||
const diffReport = fs.readFileSync('./schema_diff_output/schema_diff_report.md', 'utf8');
|
||||
|
||||
github.rest.issues.createComment({
|
||||
issue_number: context.issue.number,
|
||||
owner: context.repo.owner,
|
||||
repo: context.repo.repo,
|
||||
body: `## 📊 Database Schema Diff Report\n\n${diffReport}`
|
||||
});
|
||||
|
||||
- name: Fail if critical changes detected
|
||||
run: |
|
||||
# Check for critical severity differences
|
||||
if grep -q "🔴 Critical: [1-9]" schema_diff_output/schema_diff_report.md; then
|
||||
echo "❌ Critical schema changes detected. Manual review required."
|
||||
exit 1
|
||||
fi
|
||||
```
|
||||
|
||||
## Error Handling
|
||||
|
||||
| Error | Cause | Solution |
|
||||
|-------|-------|----------|
|
||||
| "Permission denied for schema" | Insufficient read permissions | Grant SELECT on information_schema: `GRANT USAGE ON SCHEMA information_schema TO diff_user` |
|
||||
| "Foreign key constraint violation" | Migration script drops referenced table first | Reorder script to drop constraints before tables |
|
||||
| "Column type incompatible" | Direct type conversion not supported | Add intermediate conversion step with data transformation |
|
||||
| "Unique constraint violation" | Adding unique constraint on non-unique data | Clean data first: identify duplicates, deduplicate, then add constraint |
|
||||
| "Connection timeout" | Large schema taking too long to extract | Increase timeout, or compare schemas in batches by table groups |
|
||||
|
||||
## Configuration Options
|
||||
|
||||
**Comparison Scope**
|
||||
- **Full schema**: All objects (tables, views, functions, triggers)
|
||||
- **Tables only**: Just table definitions
|
||||
- **Data types only**: Column type compatibility check
|
||||
- **Custom filter**: Compare specific tables/schemas only
|
||||
|
||||
**Migration Safety**
|
||||
- **Idempotent**: Add `IF NOT EXISTS` / `IF EXISTS` clauses
|
||||
- **Transaction-wrapped**: Wrap in BEGIN/COMMIT for atomicity
|
||||
- **Commented destructive ops**: Comment out DROP operations for review
|
||||
- **Validation checks**: Add pre-flight validation queries
|
||||
|
||||
**Output Formats**
|
||||
- **SQL**: Standard SQL migration scripts
|
||||
- **Liquibase XML**: For Liquibase-managed databases
|
||||
- **Flyway migrations**: Versioned migration files
|
||||
- **JSON**: Machine-readable diff for CI/CD integration
|
||||
|
||||
## Best Practices
|
||||
|
||||
DO:
|
||||
- Always backup target database before applying migrations
|
||||
- Test migrations in staging environment identical to production
|
||||
- Review generated migration scripts manually (don't apply blindly)
|
||||
- Use transactions for migration execution (enables rollback)
|
||||
- Version control schema snapshots for baseline comparison
|
||||
- Document schema evolution in migration comments
|
||||
- Run schema diff in CI/CD pipeline for every database change
|
||||
|
||||
DON'T:
|
||||
- Apply migrations directly to production without staging test
|
||||
- Drop columns without data archival (data loss is permanent)
|
||||
- Ignore foreign key dependencies (cascading failures)
|
||||
- Modify column types without compatibility check (data truncation risk)
|
||||
- Run large migrations during peak traffic (use maintenance window)
|
||||
- Skip rollback script generation (essential for incident recovery)
|
||||
- Compare schemas from different RDBMS (PostgreSQL ≠ MySQL)
|
||||
|
||||
## Performance Considerations
|
||||
|
||||
- **Schema extraction**: 1-5 seconds for schemas with <500 tables
|
||||
- **Diff computation**: <1 second for typical schemas
|
||||
- **Migration script generation**: <1 second
|
||||
- **Large schemas**: Batch comparison by schema or table groups
|
||||
- **Network latency**: Run diff tool close to databases (same VPC)
|
||||
- **Read replicas**: Use replica for source database to avoid production impact
|
||||
|
||||
## Security Considerations
|
||||
|
||||
- Use read-only database user for diff operations (no write permissions)
|
||||
- Encrypt connection strings in CI/CD secrets
|
||||
- Mask sensitive data in diff reports (column names, default values)
|
||||
- Audit all schema comparisons for compliance (SOC2)
|
||||
- Restrict diff tool access to database admins only
|
||||
- Secure migration scripts in version control (review before merge)
|
||||
- Log all migration executions with timestamps and operators
|
||||
|
||||
## Related Commands
|
||||
|
||||
- `/database-migration-manager` - Execute generated migration scripts
|
||||
- `/database-backup-automator` - Backup before schema changes
|
||||
- `/database-schema-designer` - Design new schemas with ERD visualization
|
||||
- `/database-connection-pooler` - Manage connections during migration
|
||||
|
||||
## Version History
|
||||
|
||||
- v1.0.0 (2024-10): Initial implementation with PostgreSQL/MySQL support
|
||||
- Planned v1.1.0: Add support for views, functions, stored procedures comparison
|
||||
61
plugin.lock.json
Normal file
61
plugin.lock.json
Normal file
@@ -0,0 +1,61 @@
|
||||
{
|
||||
"$schema": "internal://schemas/plugin.lock.v1.json",
|
||||
"pluginId": "gh:jeremylongshore/claude-code-plugins-plus:plugins/database/database-diff-tool",
|
||||
"normalized": {
|
||||
"repo": null,
|
||||
"ref": "refs/tags/v20251128.0",
|
||||
"commit": "5d58db71765ec1168c6492ecd6c3f2d37da53a45",
|
||||
"treeHash": "deca107c12e38526ad92c4e5959798f727ecb8750ccad8d0ba8af859c744635e",
|
||||
"generatedAt": "2025-11-28T10:18:19.516444Z",
|
||||
"toolVersion": "publish_plugins.py@0.2.0"
|
||||
},
|
||||
"origin": {
|
||||
"remote": "git@github.com:zhongweili/42plugin-data.git",
|
||||
"branch": "master",
|
||||
"commit": "aa1497ed0949fd50e99e70d6324a29c5b34f9390",
|
||||
"repoRoot": "/Users/zhongweili/projects/openmind/42plugin-data"
|
||||
},
|
||||
"manifest": {
|
||||
"name": "database-diff-tool",
|
||||
"description": "Database plugin for database-diff-tool",
|
||||
"version": "1.0.0"
|
||||
},
|
||||
"content": {
|
||||
"files": [
|
||||
{
|
||||
"path": "README.md",
|
||||
"sha256": "8e74cc4ecb5674b82d5427bcadc4cd8b1f9ff54e1ab8ea94831416334feec7e8"
|
||||
},
|
||||
{
|
||||
"path": ".claude-plugin/plugin.json",
|
||||
"sha256": "0d6e204e5b02dc99081ebbdc6b07556500f21665eddb2f25dc446a35988d853a"
|
||||
},
|
||||
{
|
||||
"path": "commands/db-diff.md",
|
||||
"sha256": "c847b5f45e49c75351b94f31abd5b08578dcb2e2d2a6bc6ddc90ccbfbd6b3313"
|
||||
},
|
||||
{
|
||||
"path": "skills/database-diff-tool/SKILL.md",
|
||||
"sha256": "b2db1cdbd12af3446a229ed0afdb3a48d43ba00e24cde06e73391b463a684ed1"
|
||||
},
|
||||
{
|
||||
"path": "skills/database-diff-tool/references/README.md",
|
||||
"sha256": "f869c450d613c0c048a7b8c37e25ac4a76073ae45bcc2c76bc5330eec686ee8f"
|
||||
},
|
||||
{
|
||||
"path": "skills/database-diff-tool/scripts/README.md",
|
||||
"sha256": "a94c0f89b59aeb68db34848d5866e05c843a48032959ca1779c56e1a87affcb2"
|
||||
},
|
||||
{
|
||||
"path": "skills/database-diff-tool/assets/README.md",
|
||||
"sha256": "80057f9ee98bf5b68e7e93594282701406cf4ee74c59f8bd2577d9e5f3be3d07"
|
||||
}
|
||||
],
|
||||
"dirSha256": "deca107c12e38526ad92c4e5959798f727ecb8750ccad8d0ba8af859c744635e"
|
||||
},
|
||||
"security": {
|
||||
"scannedAt": null,
|
||||
"scannerVersion": null,
|
||||
"flags": []
|
||||
}
|
||||
}
|
||||
55
skills/database-diff-tool/SKILL.md
Normal file
55
skills/database-diff-tool/SKILL.md
Normal file
@@ -0,0 +1,55 @@
|
||||
---
|
||||
name: comparing-database-schemas
|
||||
description: |
|
||||
This skill leverages the database-diff-tool plugin to compare database schemas, generate migration scripts, and provide rollback procedures. It is triggered when the user requests database schema comparisons, migration script generation, or database synchronization. Use this skill when asked to identify differences between database schemas (PostgreSQL or MySQL), create safe migration scripts with transaction safety, validate changes before deployment, or generate rollback procedures. The skill is activated by requests involving terms like "database diff", "schema comparison", "generate migration script", "database synchronization", or `/db-diff`.
|
||||
allowed-tools: Read, Write, Edit, Grep, Glob, Bash
|
||||
version: 1.0.0
|
||||
---
|
||||
|
||||
## Overview
|
||||
|
||||
This skill empowers Claude to perform production-grade database schema comparisons, generate safe migration scripts, and create rollback procedures. It simplifies the process of keeping database schemas synchronized across different environments, ensuring data integrity and minimizing downtime during deployments.
|
||||
|
||||
## How It Works
|
||||
|
||||
1. **Schema Comparison**: The plugin compares the schemas of two specified databases (PostgreSQL or MySQL), identifying differences in tables, columns, indexes, constraints, and triggers.
|
||||
2. **Migration Script Generation**: Based on the schema differences, the plugin generates a safe migration script that can be used to update the target database schema. The script includes transaction safety to prevent data corruption.
|
||||
3. **Rollback Procedure Generation**: The plugin also generates a rollback procedure that can be used to revert the changes made by the migration script in case of errors.
|
||||
|
||||
## When to Use This Skill
|
||||
|
||||
This skill activates when you need to:
|
||||
- Compare database schemas between different environments (e.g., development, staging, production).
|
||||
- Generate migration scripts to update a database schema to the latest version.
|
||||
- Create rollback procedures to revert database schema changes.
|
||||
- Synchronize database schemas across multiple environments to ensure consistency.
|
||||
|
||||
## Examples
|
||||
|
||||
### Example 1: Generating a Migration Script
|
||||
|
||||
User request: "Generate a migration script to update the staging database schema to match production."
|
||||
|
||||
The skill will:
|
||||
1. Connect to both the staging and production databases.
|
||||
2. Compare the schemas of the two databases using the database-diff-tool plugin.
|
||||
3. Generate a migration script that updates the staging database schema to match the production schema, including transaction safety and rollback procedures.
|
||||
|
||||
### Example 2: Comparing Database Schemas
|
||||
|
||||
User request: "Compare the database schemas of the development and testing environments."
|
||||
|
||||
The skill will:
|
||||
1. Connect to both the development and testing databases.
|
||||
2. Compare the schemas of the two databases using the database-diff-tool plugin.
|
||||
3. Report the differences between the two schemas, including any missing tables, columns, indexes, or constraints.
|
||||
|
||||
## Best Practices
|
||||
|
||||
- **Database Credentials**: Ensure that Claude has access to the necessary database credentials to connect to the databases being compared.
|
||||
- **Backup**: Always back up the database before running any migration scripts.
|
||||
- **Validation**: Validate the generated migration script in a test environment before deploying it to production.
|
||||
|
||||
## Integration
|
||||
|
||||
This skill can be integrated with other CI/CD tools to automate the database migration process. It can also be used in conjunction with other database management tools to monitor database schema changes and ensure data integrity.
|
||||
8
skills/database-diff-tool/assets/README.md
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8
skills/database-diff-tool/assets/README.md
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@@ -0,0 +1,8 @@
|
||||
# Assets
|
||||
|
||||
Bundled resources for database-diff-tool skill
|
||||
|
||||
- [ ] migration_template.sql: Template for generating SQL migration scripts.
|
||||
- [ ] rollback_template.sql: Template for generating SQL rollback scripts.
|
||||
- [ ] example_schema_before.sql: Example database schema before changes.
|
||||
- [ ] example_schema_after.sql: Example database schema after changes.
|
||||
8
skills/database-diff-tool/references/README.md
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8
skills/database-diff-tool/references/README.md
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@@ -0,0 +1,8 @@
|
||||
# References
|
||||
|
||||
Bundled resources for database-diff-tool skill
|
||||
|
||||
- [ ] postgresql_schema_best_practices.md: Best practices for PostgreSQL schema design and management.
|
||||
- [ ] mysql_schema_best_practices.md: Best practices for MySQL schema design and management.
|
||||
- [ ] database_migration_strategies.md: Different strategies for database migration, including zero-downtime deployments.
|
||||
- [ ] database_schema_comparison_api.md: API documentation for the database schema comparison tool.
|
||||
7
skills/database-diff-tool/scripts/README.md
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7
skills/database-diff-tool/scripts/README.md
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@@ -0,0 +1,7 @@
|
||||
# Scripts
|
||||
|
||||
Bundled resources for database-diff-tool skill
|
||||
|
||||
- [ ] generate_migration_script.py: Generates database migration scripts based on the schema differences.
|
||||
- [ ] rollback_migration.py: Creates rollback scripts to revert database changes.
|
||||
- [ ] validate_schema_changes.py: Validates the schema changes before applying them to the database.
|
||||
Reference in New Issue
Block a user