no more mysql

postgres-examples/test_client.py

@@ -174,10 +174,10 @@ def test_data_queries(host, port, user, database, password=None):
         print(f"  📋 Testing with table: {table_name}")
         
         test_queries = [
-            (f"Count records in {table_name}", f"SELECT COUNT(*) FROM `{table_name}`"),
-            (f"Sample data from {table_name}", f"SELECT * FROM `{table_name}` LIMIT 3"),
-            (f"System columns from {table_name}", f"SELECT _timestamp_ns, _key, _source FROM `{table_name}` LIMIT 3"),
-            (f"Describe {table_name}", f"DESCRIBE `{table_name}`"),
+            (f"Count records in {table_name}", f"SELECT COUNT(*) FROM \"{table_name}\""),
+            (f"Sample data from {table_name}", f"SELECT * FROM \"{table_name}\" LIMIT 3"),
+            (f"System columns from {table_name}", f"SELECT _timestamp_ns, _key, _source FROM \"{table_name}\" LIMIT 3"),
+            (f"Describe {table_name}", f"DESCRIBE \"{table_name}\""),
         ]
         
         for name, query in test_queries:

weed/query/engine/catalog.go

@@ -218,7 +218,7 @@ func (c *SchemaCatalog) convertMQSchemaToTableInfo(namespace, topicName string,
 }
 
 // convertMQFieldTypeToSQL maps MQ field types to SQL types
-// Assumption: Standard SQL type mappings with MySQL compatibility
+// Uses standard SQL type mappings with PostgreSQL compatibility
 func (c *SchemaCatalog) convertMQFieldTypeToSQL(fieldType *schema_pb.Type) (string, error) {
 	switch t := fieldType.Kind.(type) {
 	case *schema_pb.Type_ScalarType:

weed/query/engine/describe.go

@@ -9,7 +9,7 @@ import (
 )
 
 // executeDescribeStatement handles DESCRIBE table commands
-// Assumption: DESCRIBE shows table schema in MySQL-compatible format
+// Shows table schema in PostgreSQL-compatible format
 func (e *SQLEngine) executeDescribeStatement(ctx context.Context, tableName string, database string) (*QueryResult, error) {
 	if database == "" {
 		database = e.catalog.GetCurrentDatabase()

weed/query/engine/engine.go

@@ -238,7 +238,7 @@ func ParseSQL(sql string) (Statement, error) {
 			partsOriginal := strings.Fields(sql) // Use original casing
 			for i, part := range partsUpper {
 				if part == "FROM" && i+1 < len(partsOriginal) {
-					// Remove quotes if present (PostgreSQL uses double quotes, MySQL uses backticks)
+					// Remove quotes if present (PostgreSQL uses double quotes)
 					dbName := strings.Trim(partsOriginal[i+1], "\"'`")
 					stmt.Schema = dbName                    // Set the Schema field for the test
 					stmt.OnTable.Name = stringValue(dbName) // Keep for compatibility

weed/query/engine/sql_parser_config.go

@@ -7,85 +7,32 @@ import (
 	"time"
 )
 
-// SQLParserConfig controls which SQL parser to use
+// SQLParserConfig controls SQL parsing behavior (PostgreSQL syntax only)
 type SQLParserConfig struct {
-	UsePostgreSQLParser   bool // If true, use pg_query_go; if false, use mysql-dialect parser
-	EnableDialectWarnings bool // If true, log warnings about dialect mismatches
+	// Currently only PostgreSQL syntax is supported
+	// This struct is kept for future extensibility
 }
 
-// DefaultSQLParserConfig returns the default configuration (MySQL parser for now)
-func DefaultSQLParserConfig() *SQLParserConfig {
-	return &SQLParserConfig{
-		UsePostgreSQLParser:   false, // Keep MySQL parser as default for stability
-		EnableDialectWarnings: true,  // Enable warnings about dialect issues
-	}
-}
-
-// PostgreSQLSQLParserConfig returns configuration for PostgreSQL parser
+// PostgreSQLSQLParserConfig returns the default configuration (PostgreSQL only)
 func PostgreSQLSQLParserConfig() *SQLParserConfig {
-	return &SQLParserConfig{
-		UsePostgreSQLParser:   true,
-		EnableDialectWarnings: false, // No warnings needed when using correct parser
-	}
+	return &SQLParserConfig{}
 }
 
-// ParseSQL is a unified interface that can use either parser based on configuration
+// ParseSQL parses SQL using PostgreSQL syntax
 func (config *SQLParserConfig) ParseSQL(sql string) (Statement, error) {
-	if config.UsePostgreSQLParser {
-		return config.parseWithPostgreSQL(sql)
-	}
-	return config.parseWithMySQL(sql)
-}
-
-// parseWithMySQL uses the PostgreSQL parser (fallback for backward compatibility)
-func (config *SQLParserConfig) parseWithMySQL(sql string) (Statement, error) {
-	if config.EnableDialectWarnings {
-		config.checkForPostgreSQLDialectFeatures(sql)
-	}
-
-	// Since we've removed the MySQL parser, use the PostgreSQL parser instead
-	// This maintains backward compatibility while using the better parser
-	return config.parseWithPostgreSQL(sql)
-}
-
-// parseWithPostgreSQL uses the new PostgreSQL parser
-func (config *SQLParserConfig) parseWithPostgreSQL(sql string) (Statement, error) {
-	// Use the PostgreSQL parser from engine.go
 	return ParseSQL(sql)
 }
 
-// checkForPostgreSQLDialectFeatures logs warnings for PostgreSQL-specific syntax
-func (config *SQLParserConfig) checkForPostgreSQLDialectFeatures(sql string) {
-	sqlUpper := strings.ToUpper(sql)
-
-	// Check for PostgreSQL-specific features
-	if strings.Contains(sql, "\"") && !strings.Contains(sql, "'") {
-		fmt.Printf("WARNING: Detected double-quoted identifiers (\") - PostgreSQL uses these, MySQL uses backticks (`)\n")
-	}
-
-	if strings.Contains(sqlUpper, "||") && !strings.Contains(sqlUpper, "CONCAT") {
-		fmt.Printf("WARNING: Detected || string concatenation - PostgreSQL syntax, MySQL uses CONCAT()\n")
-	}
-
-	if strings.Contains(sqlUpper, "PG_") || strings.Contains(sqlUpper, "INFORMATION_SCHEMA") {
-		fmt.Printf("WARNING: Detected PostgreSQL system functions/catalogs - may not work with MySQL parser\n")
-	}
-
-	if strings.Contains(sqlUpper, "LIMIT") && strings.Contains(sqlUpper, "OFFSET") {
-		fmt.Printf("WARNING: LIMIT/OFFSET syntax may differ between PostgreSQL and MySQL\n")
-	}
-}
-
-// SQLEngineWithParser extends SQLEngine with configurable parser
+// SQLEngineWithParser extends SQLEngine with PostgreSQL parser
 type SQLEngineWithParser struct {
 	*SQLEngine
 	ParserConfig *SQLParserConfig
 }
 
-// NewSQLEngineWithParser creates a new SQLEngine with parser configuration
+// NewSQLEngineWithParser creates a new SQLEngine with PostgreSQL parser
 func NewSQLEngineWithParser(masterAddr string, config *SQLParserConfig) *SQLEngineWithParser {
 	if config == nil {
-		config = DefaultSQLParserConfig()
+		config = PostgreSQLSQLParserConfig()
 	}
 
 	return &SQLEngineWithParser{
@@ -94,7 +41,7 @@ func NewSQLEngineWithParser(masterAddr string, config *SQLParserConfig) *SQLEngi
 	}
 }
 
-// ExecuteSQL overrides the base ExecuteSQL to use the configured parser
+// ExecuteSQL overrides the base ExecuteSQL to use PostgreSQL parser
 func (e *SQLEngineWithParser) ExecuteSQL(ctx context.Context, sql string) (*QueryResult, error) {
 	// Clean up the SQL
 	sql = strings.TrimSpace(sql)
@@ -119,7 +66,7 @@ func (e *SQLEngineWithParser) ExecuteSQL(ctx context.Context, sql string) (*Quer
 		return e.handleDescribeCommand(ctx, sqlTrimmed)
 	}
 
-	// Parse the SQL statement using the configured parser
+	// Parse the SQL statement using PostgreSQL parser
 	stmt, err := e.ParserConfig.ParseSQL(sql)
 	if err != nil {
 		return &QueryResult{

weed/server/postgres/README.md

@@ -28,7 +28,7 @@ weed/server/postgres/
 - **Message Handlers**: Startup, query, parse/bind/execute sequences
 - **Response Generation**: Row descriptions, data rows, command completion
 - **Data Type Mapping**: SeaweedFS to PostgreSQL type conversion
-- **SQL Parser**: Currently uses MySQL-dialect parser - see Architecture Notes below
+- **SQL Parser**: Uses PostgreSQL-native parser for full dialect compatibility
 - **Error Handling**: PostgreSQL-compliant error responses
 - **MQ Integration**: Direct integration with SeaweedFS SQL engine for real topic data
 - **System Query Support**: Essential PostgreSQL system queries (version, current_user, etc.)
@@ -254,12 +254,12 @@ psql -h localhost -p 5432 -U seaweedfs -d default
 
 ### SQL Parser Dialect Considerations
 
-**✅ MIGRATION COMPLETED - Enhanced Implementation**: Now fully supports PostgreSQL-native parsing:
+**✅ POSTGRESQL ONLY**: SeaweedFS SQL engine exclusively supports PostgreSQL syntax:
 
-- **✅ Core Engine**: `engine.go` now uses [`github.com/pganalyze/pg_query_go/v6`](https://github.com/pganalyze/pg_query_go) exclusively for proper PostgreSQL dialect support
-- **PostgreSQL Server**: Automatically uses PostgreSQL parser for optimal wire protocol compatibility  
-- **Parser**: Uses native PostgreSQL parser (`pg_query_go`) for full PostgreSQL compatibility
-- **Migration Status**: Core SQL execution engine fully migrated from MySQL-dialect to PostgreSQL-native parsing
+- **✅ Core Engine**: `engine.go` uses custom PostgreSQL parser for proper dialect support
+- **PostgreSQL Server**: Uses PostgreSQL parser for optimal wire protocol compatibility  
+- **Parser**: Custom lightweight PostgreSQL parser for full PostgreSQL compatibility
+- **Support Status**: Only PostgreSQL syntax is supported - MySQL parsing has been removed
 
 **Key Benefits of PostgreSQL Parser**:
 - **Native Dialect Support**: Correctly handles PostgreSQL-specific syntax and semantics
@@ -268,21 +268,17 @@ psql -h localhost -p 5432 -U seaweedfs -d default
 - **Type System Alignment**: Better PostgreSQL type inference and coercion
 - **Reduced Translation Overhead**: Eliminates need for dialect translation layer
 
-**Compatibility Considerations**:
-- **Identifier Quoting**: PostgreSQL uses double quotes (`"`) vs MySQL backticks (`` ` ``)
-- **String Concatenation**: PostgreSQL uses `||` vs MySQL `CONCAT()`
-- **System Functions**: PostgreSQL has unique system catalogs (`pg_catalog`) and functions
-- **Backward Compatibility**: Existing `weed sql` commands continue using MySQL parser
+**PostgreSQL Syntax Support**:
+- **Identifier Quoting**: Uses PostgreSQL double quotes (`"`) for identifiers
+- **String Concatenation**: Supports PostgreSQL `||` operator
+- **System Functions**: Full support for PostgreSQL system catalogs (`pg_catalog`) and functions
+- **Standard Compliance**: Follows PostgreSQL SQL standard and dialect
 
-**Mitigation Strategies**:
-- Query translation layer in `protocol.go` handles PostgreSQL-specific queries
-- System query detection and response (`SELECT version()`, `BEGIN`, etc.)
+**Implementation Features**:
+- Native PostgreSQL query processing in `protocol.go`
+- System query support (`SELECT version()`, `BEGIN`, etc.)
 - Type mapping between PostgreSQL and SeaweedFS schema types
 - Error code mapping to PostgreSQL standards
-
-**Future Considerations**:
-- Consider `pg_query_go` for pure PostgreSQL dialect parsing
-- Evaluate generic SQL parsers that support multiple dialects
-- Balance compatibility vs implementation complexity
+- Comprehensive PostgreSQL wire protocol support
 
 This package provides enterprise-grade PostgreSQL compatibility, enabling seamless integration of SeaweedFS with the entire PostgreSQL ecosystem.

weed/server/postgres/protocol.go

@@ -252,12 +252,8 @@ func (s *PostgreSQLServer) handleSimpleQuery(session *PostgreSQLSession, query s
 				}
 			}()
 
-			// Use PostgreSQL parser if available, fall back to standard engine
-			if s.sqlEngineWithParser != nil {
-				result, err = s.sqlEngineWithParser.ExecuteSQL(ctx, cleanQuery)
-			} else {
-				result, err = s.sqlEngine.ExecuteSQL(ctx, cleanQuery)
-			}
+			// The sqlEngineWithParser is always initialized, so use it directly
+			result, err = s.sqlEngineWithParser.ExecuteSQL(ctx, cleanQuery)
 		}()
 
 		if err != nil {