refactor: parameterize MySQL queries, add CI/CD pipeline, update README for multi-DB support

Meru143 · Meru143 · commit 84ba3ff9bcbc · 2026-03-04T22:11:34.000+05:30
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -7,7 +7,7 @@ on:
     branches: [ main ]
 
 jobs:
-  build:
+  unit-tests:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
@@ -23,7 +23,7 @@ jobs:
       - name: Build
         run: go build -v ./...
 
-      - name: Test
+      - name: Unit Tests
         run: go test -v -race -coverprofile=coverage.out ./...
 
       - name: Check coverage
@@ -46,3 +46,87 @@ jobs:
         with:
           files: ./coverage.out
           flags: unittests
+
+  integration-tests:
+    runs-on: ubuntu-latest
+    needs: unit-tests
+    services:
+      postgres-source:
+        image: postgres:16-alpine
+        env:
+          POSTGRES_USER: testuser
+          POSTGRES_PASSWORD: testpass
+          POSTGRES_DB: sourcedb
+        ports:
+          - 5432:5432
+        options: >-
+          --health-cmd pg_isready
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 5
+
+      postgres-target:
+        image: postgres:16-alpine
+        env:
+          POSTGRES_USER: testuser
+          POSTGRES_PASSWORD: testpass
+          POSTGRES_DB: targetdb
+        ports:
+          - 5433:5432
+        options: >-
+          --health-cmd pg_isready
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 5
+
+      mysql-source:
+        image: mysql:8.0
+        env:
+          MYSQL_ROOT_PASSWORD: rootpass
+          MYSQL_DATABASE: sourcedb
+          MYSQL_USER: testuser
+          MYSQL_PASSWORD: testpass
+        ports:
+          - 3306:3306
+        options: >-
+          --health-cmd "mysqladmin ping -h 127.0.0.1"
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 10
+
+      mysql-target:
+        image: mysql:8.0
+        env:
+          MYSQL_ROOT_PASSWORD: rootpass
+          MYSQL_DATABASE: targetdb
+          MYSQL_USER: testuser
+          MYSQL_PASSWORD: testpass
+        ports:
+          - 3307:3306
+        options: >-
+          --health-cmd "mysqladmin ping -h 127.0.0.1"
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 10
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: '1.21'
+
+      - name: Download dependencies
+        run: go mod download
+
+      - name: Wait for services
+        run: sleep 15
+
+      - name: Run Integration Tests
+        run: go run -tags=integration test/integration_main.go
+        env:
+          PG_SOURCE_DSN: "postgres://testuser:testpass@localhost:5432/sourcedb?sslmode=disable"
+          PG_TARGET_DSN: "postgres://testuser:testpass@localhost:5433/targetdb?sslmode=disable"
+          MYSQL_SOURCE_DSN: "testuser:testpass@tcp(localhost:3306)/sourcedb?multiStatements=true"
+          MYSQL_TARGET_DSN: "testuser:testpass@tcp(localhost:3307)/targetdb?multiStatements=true"
diff --git a/README.md b/README.md
@@ -5,18 +5,21 @@
 [![Coverage](https://codecov.io/gh/meru143/dbdiff/branch/main/graph/badge.svg)](https://codecov.io/gh/meru143/dbdiff)
 [![Go Version](https://img.shields.io/github/go-mod/go-version/meru143/dbdiff)](https://github.com/meru143/dbdiff)
 
-PostgreSQL schema comparison and migration CLI tool.
+Multi-database schema comparison and migration CLI tool. Supports **PostgreSQL** and **MySQL**.
 
 ## Features
 
-- Compare PostgreSQL schemas between two databases
+- Compare database schemas between two instances
 - Generate migration SQL scripts
+- **Multi-database support**: PostgreSQL and MySQL
+- Dialect-aware SQL generation (e.g., `MODIFY COLUMN` for MySQL, `ALTER COLUMN TYPE` for PostgreSQL)
 - Multiple output formats: SQL, Table, JSON
 - Dry-run mode (default)
 - Schema filtering
 - Ignore patterns for columns
 - Transaction wrapper support
 - SSL/TLS connection support
+- Migration tracking
 
 ## Installation
 
@@ -34,16 +37,32 @@ chmod +x dbdiff
 
 ## Usage
 
+### PostgreSQL
+
 ```bash
-# Compare two databases
+# Compare two PostgreSQL databases
 dbdiff compare postgres://user:pass@localhost:5432/db1 postgres://user:pass@localhost:5432/db2
 
 # Generate migration
 dbdiff migrate -s postgres://localhost:5432/db1 -t postgres://localhost:5432/db2 -o migration.sql
 
 # Show table diff
 dbdiff diff postgres://localhost:5432/db1 postgres://localhost:5432/db2 --format table
+```
+
+### MySQL
+
+```bash
+# Compare two MySQL databases
+dbdiff compare mysql://user:pass@tcp(localhost:3306)/db1 mysql://user:pass@tcp(localhost:3306)/db2
+
+# Generate migration
+dbdiff migrate -s mysql://user:pass@tcp(localhost:3306)/db1 -t mysql://user:pass@tcp(localhost:3306)/db2 -o migration.sql
+```
+
+### General Commands
 
+```bash
 # List tables
 dbdiff tables postgres://localhost:5432/db
 
@@ -66,6 +85,13 @@ ignore_patterns:
   - "_updated_at"
 ```
 
+## Supported Databases
+
+| Database   | Introspection | Migration SQL | Dialect-Aware DDL |
+|------------|:---:|:---:|:---:|
+| PostgreSQL | ✅ | ✅ | ✅ |
+| MySQL 8.0+ | ✅ | ✅ | ✅ |
+
 ## Flags
 
 | Flag | Short | Description | Default |
@@ -74,7 +100,7 @@ ignore_patterns:
 | --target | -t | Target database URL | |
 | --output | -o | Output file path | stdout |
 | --format | | Output format: sql, table, json | sql |
-| --schema | | PostgreSQL schema | public |
+| --schema | | Database schema | public |
 | --dry-run | | Dry-run mode (don't write) | true |
 | --force | -f | Skip confirmation prompt | false |
 | --timeout | | Query timeout | 30s |
@@ -97,6 +123,20 @@ ignore_patterns:
 | DBDIFF_LOG_LEVEL | Log level: debug, info, warn, error |
 | DBDIFF_CONFIG | Config file path |
 
+## Development
+
+### Running Tests
+
+```bash
+# Unit tests
+go test ./...
+
+# Integration tests (requires Docker)
+docker compose -f docker-compose.test.yml up -d
+go run -tags=integration test/integration_main.go
+docker compose -f docker-compose.test.yml down
+```
+
 ## License
 
 MIT License - see [LICENSE](LICENSE)
diff --git a/internal/db/mysql/mysql.go b/internal/db/mysql/mysql.go
@@ -85,8 +85,12 @@ func (d *Driver) Dialect() string {
 // Introspect performs full schema introspection for MySQL
 func (d *Driver) Introspect(ctx context.Context, schema string, ignorePatterns []string) (*types.Schema, error) {
 	if schema == "" {
-		// In MySQL, schema is database
-		schema = "DATABASE()" // Or get current DB
+		// Query the current database name
+		var dbName string
+		if err := d.db.QueryRowContext(ctx, "SELECT DATABASE()").Scan(&dbName); err != nil {
+			return nil, fmt.Errorf("failed to determine current database: %w", err)
+		}
+		schema = dbName
 	}
 
 	result := &types.Schema{}
diff --git a/internal/db/mysql/mysql_test.go b/internal/db/mysql/mysql_test.go
@@ -177,9 +177,10 @@ func TestIntrospectMocked(t *testing.T) {
 	ctx := context.Background()
 	schemaName := "test_schema"
 
-	// Mock getTables
+	// Mock getTables (ListTables now takes schema as param)
 	tableRows := sqlmock.NewRows([]string{"TABLE_NAME"}).AddRow("users")
 	mock.ExpectQuery(`SELECT table_name FROM information_schema\.tables`).
+		WithArgs(schemaName).
 		WillReturnRows(tableRows)
 
 	// Mock getColumns
@@ -189,37 +190,38 @@ func TestIntrospectMocked(t *testing.T) {
 		AddRow("email", "varchar", nil, "YES", 0)
 
 	mock.ExpectQuery(`SELECT c\.COLUMN_NAME, c\.DATA_TYPE`).
-		WithArgs("users").
+		WithArgs(schemaName, "users").
 		WillReturnRows(colRows)
 
 	// Mock getIndexes
 	idxRows := sqlmock.NewRows([]string{"INDEX_NAME", "is_unique", "is_primary", "COLUMN_NAME"}).
 		AddRow("idx_email", false, false, "email")
 	mock.ExpectQuery(`SELECT INDEX_NAME, NON_UNIQUE \= 0 AS is_unique, INDEX_NAME \= 'PRIMARY' AS is_primary, COLUMN_NAME`).
-		WithArgs("users").
+		WithArgs(schemaName, "users").
 		WillReturnRows(idxRows)
 
 	// Mock getConstraints
 	cstRows := sqlmock.NewRows([]string{"CONSTRAINT_NAME", "CONSTRAINT_TYPE", "COLUMN_NAME"}).
 		AddRow("chk_age", "CHECK", "age")
 	mock.ExpectQuery(`SELECT tc\.CONSTRAINT_NAME, tc\.CONSTRAINT_TYPE, kcu\.COLUMN_NAME`).
-		WithArgs("users").
+		WithArgs(schemaName, "users").
 		WillReturnRows(cstRows)
 
 	// Mock getForeignKeys
 	fkRows := sqlmock.NewRows([]string{"CONSTRAINT_NAME", "COLUMN_NAME", "REFERENCED_TABLE_NAME", "REFERENCED_COLUMN_NAME"}).
 		AddRow("fk_user", "user_id", "users", "id")
 	mock.ExpectQuery(`SELECT CONSTRAINT_NAME, COLUMN_NAME, REFERENCED_TABLE_NAME, REFERENCED_COLUMN_NAME`).
-		WithArgs("users").
+		WithArgs(schemaName, "users").
 		WillReturnRows(fkRows)
 
 	mock.ExpectQuery(`SELECT UPDATE_RULE, DELETE_RULE`).
-		WithArgs("fk_user").
+		WithArgs(schemaName, "fk_user").
 		WillReturnRows(sqlmock.NewRows([]string{"UPDATE_RULE", "DELETE_RULE"}).AddRow("RESTRICT", "CASCADE"))
 
 	// Mock getViews
 	viewRows := sqlmock.NewRows([]string{"TABLE_NAME", "VIEW_DEFINITION"}).AddRow("v_users", "SELECT * FROM users")
 	mock.ExpectQuery(`SELECT TABLE_NAME, VIEW_DEFINITION FROM information_schema.VIEWS`).
+		WithArgs(schemaName).
 		WillReturnRows(viewRows)
 
 	schema, err := d.Introspect(ctx, schemaName, nil)
diff --git a/internal/db/mysql/queries.go b/internal/db/mysql/queries.go
@@ -15,8 +15,8 @@ var DefaultIgnorePatterns = []string{"_created_at", "_updated_at", "_modified_at
 // ListTables returns table names in the given schema
 func (d *Driver) ListTables(ctx context.Context, schema string, ignorePatterns []string) ([]string, error) {
 	// In MySQL, the schema is often just the currently selected DB
-	query := "SELECT table_name FROM information_schema.tables WHERE table_schema = DATABASE() AND table_type = 'BASE TABLE'"
-	rows, err := d.db.QueryContext(ctx, query)
+	query := "SELECT table_name FROM information_schema.tables WHERE table_schema = ? AND table_type = 'BASE TABLE'"
+	rows, err := d.db.QueryContext(ctx, query, schema)
 	if err != nil {
 		return nil, err
 	}
@@ -104,9 +104,9 @@ func getColumns(ctx context.Context, dbConn *sql.DB, schemaName, tableName strin
 			AND c.TABLE_NAME = k.TABLE_NAME 
 			AND c.COLUMN_NAME = k.COLUMN_NAME 
 			AND k.CONSTRAINT_NAME = 'PRIMARY'
-		WHERE c.TABLE_SCHEMA = DATABASE() AND c.TABLE_NAME = ?
+		WHERE c.TABLE_SCHEMA = ? AND c.TABLE_NAME = ?
 		ORDER BY c.ORDINAL_POSITION`
-	rows, err := dbConn.QueryContext(ctx, query, tableName)
+	rows, err := dbConn.QueryContext(ctx, query, schemaName, tableName)
 	if err != nil {
 		return nil, err
 	}
@@ -140,10 +140,10 @@ func getIndexes(ctx context.Context, dbConn *sql.DB, schemaName, tableName strin
 			INDEX_NAME = 'PRIMARY' AS is_primary,
 			COLUMN_NAME
 		FROM information_schema.STATISTICS 
-		WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = ?
+		WHERE TABLE_SCHEMA = ? AND TABLE_NAME = ?
 		ORDER BY INDEX_NAME, SEQ_IN_INDEX`
 
-	rows, err := dbConn.QueryContext(ctx, query, tableName)
+	rows, err := dbConn.QueryContext(ctx, query, schemaName, tableName)
 	if err != nil {
 		return nil, err
 	}
@@ -193,10 +193,10 @@ func getConstraints(ctx context.Context, dbConn *sql.DB, schemaName, tableName s
 		FROM information_schema.TABLE_CONSTRAINTS tc
 		JOIN information_schema.KEY_COLUMN_USAGE kcu
 			ON tc.CONSTRAINT_NAME = kcu.CONSTRAINT_NAME AND tc.TABLE_SCHEMA = kcu.TABLE_SCHEMA
-		WHERE tc.TABLE_SCHEMA = DATABASE() AND tc.TABLE_NAME = ? AND tc.CONSTRAINT_TYPE IN ('PRIMARY KEY', 'UNIQUE', 'CHECK')
+		WHERE tc.TABLE_SCHEMA = ? AND tc.TABLE_NAME = ? AND tc.CONSTRAINT_TYPE IN ('PRIMARY KEY', 'UNIQUE', 'CHECK')
 		ORDER BY tc.CONSTRAINT_NAME, kcu.ORDINAL_POSITION`
 
-	rows, err := dbConn.QueryContext(ctx, query, tableName)
+	rows, err := dbConn.QueryContext(ctx, query, schemaName, tableName)
 	if err != nil {
 		return nil, err
 	}
@@ -239,10 +239,10 @@ func getForeignKeys(ctx context.Context, dbConn *sql.DB, schemaName, tableName s
 			REFERENCED_TABLE_NAME,
 			REFERENCED_COLUMN_NAME
 		FROM information_schema.KEY_COLUMN_USAGE 
-		WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = ? AND REFERENCED_TABLE_NAME IS NOT NULL
+		WHERE TABLE_SCHEMA = ? AND TABLE_NAME = ? AND REFERENCED_TABLE_NAME IS NOT NULL
 		ORDER BY CONSTRAINT_NAME, ORDINAL_POSITION`
 
-	rows, err := dbConn.QueryContext(ctx, query, tableName)
+	rows, err := dbConn.QueryContext(ctx, query, schemaName, tableName)
 	if err != nil {
 		return nil, err
 	}
@@ -274,9 +274,9 @@ func getForeignKeys(ctx context.Context, dbConn *sql.DB, schemaName, tableName s
 	var fks []types.ForeignKey
 	for _, name := range orderedNames {
 		// fetch on update / delete
-		rcQuery := `SELECT UPDATE_RULE, DELETE_RULE FROM information_schema.REFERENTIAL_CONSTRAINTS WHERE CONSTRAINT_SCHEMA = DATABASE() AND CONSTRAINT_NAME = ?`
+		rcQuery := `SELECT UPDATE_RULE, DELETE_RULE FROM information_schema.REFERENTIAL_CONSTRAINTS WHERE CONSTRAINT_SCHEMA = ? AND CONSTRAINT_NAME = ?`
 		var onUpd, onDel string
-		if err := dbConn.QueryRowContext(ctx, rcQuery, name).Scan(&onUpd, &onDel); err == nil {
+		if err := dbConn.QueryRowContext(ctx, rcQuery, schemaName, name).Scan(&onUpd, &onDel); err == nil {
 			fkMap[name].OnUpdate = onUpd
 			fkMap[name].OnDelete = onDel
 		}
@@ -287,8 +287,8 @@ func getForeignKeys(ctx context.Context, dbConn *sql.DB, schemaName, tableName s
 }
 
 func getViews(ctx context.Context, dbConn *sql.DB, schemaName string) ([]types.View, error) {
-	query := `SELECT TABLE_NAME, VIEW_DEFINITION FROM information_schema.VIEWS WHERE TABLE_SCHEMA = DATABASE()`
-	rows, err := dbConn.QueryContext(ctx, query)
+	query := `SELECT TABLE_NAME, VIEW_DEFINITION FROM information_schema.VIEWS WHERE TABLE_SCHEMA = ?`
+	rows, err := dbConn.QueryContext(ctx, query, schemaName)
 	if err != nil {
 		return nil, err
 	}
diff --git a/internal/db/mysql/queries_test.go b/internal/db/mysql/queries_test.go
@@ -78,11 +78,12 @@ func TestListTables(t *testing.T) {
 		AddRow("posts").
 		AddRow("_created_at") // This should be ignored by DefaultIgnorePatterns
 
-	// The query uses DATABASE() and 'BASE TABLE'
-	mock.ExpectQuery(`SELECT table_name FROM information_schema.tables WHERE table_schema = DATABASE\(\) AND table_type = 'BASE TABLE'`).
+	// The query now uses parameterized schema
+	mock.ExpectQuery(`SELECT table_name FROM information_schema.tables WHERE table_schema = \? AND table_type = 'BASE TABLE'`).
+		WithArgs("testdb").
 		WillReturnRows(rows)
 
-	tables, err := d.ListTables(ctx, "testdb", DefaultIgnorePatterns) // schema arg is ignored in query string anyway
+	tables, err := d.ListTables(ctx, "testdb", DefaultIgnorePatterns)
 	if err != nil {
 		t.Errorf("unexpected error: %s", err)
 	}
