refactor: move ClickHouse support to parse command only

Remove ClickHouse from compiler/engine.go and config.go.
Add --dialect clickhouse support to the sqlc parse command.

Co-Authored-By: Claude <noreply@anthropic.com>

Author: kyleconroy

internal/cmd/parse.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/spf13/cobra"
 
+	"github.com/sqlc-dev/sqlc/internal/engine/clickhouse"
 	"github.com/sqlc-dev/sqlc/internal/engine/dolphin"
 	"github.com/sqlc-dev/sqlc/internal/engine/postgresql"
 	"github.com/sqlc-dev/sqlc/internal/engine/sqlite"
@@ -27,15 +28,18 @@ Examples:
   echo "SELECT * FROM users" | sqlc parse --dialect mysql
 
   # Parse SQLite SQL
-  sqlc parse --dialect sqlite queries.sql`,
+  sqlc parse --dialect sqlite queries.sql
+
+  # Parse ClickHouse SQL
+  sqlc parse --dialect clickhouse queries.sql`,
 	Args: cobra.MaximumNArgs(1),
 	RunE: func(cmd *cobra.Command, args []string) error {
 		dialect, err := cmd.Flags().GetString("dialect")
 		if err != nil {
 			return err
 		}
 		if dialect == "" {
-			return fmt.Errorf("--dialect flag is required (postgresql, mysql, or sqlite)")
+			return fmt.Errorf("--dialect flag is required (postgresql, mysql, sqlite, or clickhouse)")
 		}
 
 		// Determine input source
@@ -71,8 +75,11 @@ Examples:
 		case "sqlite":
 			parser := sqlite.NewParser()
 			stmts, err = parser.Parse(input)
+		case "clickhouse":
+			parser := clickhouse.NewParser()
+			stmts, err = parser.Parse(input)
 		default:
-			return fmt.Errorf("unsupported dialect: %s (use postgresql, mysql, or sqlite)", dialect)
+			return fmt.Errorf("unsupported dialect: %s (use postgresql, mysql, sqlite, or clickhouse)", dialect)
 		}
 		if err != nil {
 			return fmt.Errorf("parse error: %w", err)

internal/compiler/engine.go

@@ -7,7 +7,6 @@ import (
 	"github.com/sqlc-dev/sqlc/internal/analyzer"
 	"github.com/sqlc-dev/sqlc/internal/config"
 	"github.com/sqlc-dev/sqlc/internal/dbmanager"
-	"github.com/sqlc-dev/sqlc/internal/engine/clickhouse"
 	"github.com/sqlc-dev/sqlc/internal/engine/dolphin"
 	"github.com/sqlc-dev/sqlc/internal/engine/postgresql"
 	pganalyze "github.com/sqlc-dev/sqlc/internal/engine/postgresql/analyzer"
@@ -83,10 +82,6 @@ func NewCompiler(conf config.SQL, combo config.CombinedSettings, parserOpts opts
 		c.parser = dolphin.NewParser()
 		c.catalog = dolphin.NewCatalog()
 		c.selector = newDefaultSelector()
-	case config.EngineClickHouse:
-		c.parser = clickhouse.NewParser()
-		c.catalog = clickhouse.NewCatalog()
-		c.selector = newDefaultSelector()
 	case config.EnginePostgreSQL:
 		parser := postgresql.NewParser()
 		c.parser = parser

internal/config/config.go

@@ -51,10 +51,9 @@ func (p *Paths) UnmarshalYAML(unmarshal func(interface{}) error) error {
 }
 
 const (
-	EngineMySQL       Engine = "mysql"
-	EnginePostgreSQL  Engine = "postgresql"
-	EngineSQLite      Engine = "sqlite"
-	EngineClickHouse  Engine = "clickhouse"
+	EngineMySQL      Engine = "mysql"
+	EnginePostgreSQL Engine = "postgresql"
+	EngineSQLite     Engine = "sqlite"
 )
 
 type Config struct {