V1.5.24

cmd/sling/sling_test.go

@@ -1158,23 +1158,26 @@ func TestSuiteDatabaseD1(t *testing.T) {
 
 func TestSuiteDatabaseDuckDb(t *testing.T) {
 	t.Parallel()
+
+	// DUCKDB
 	testSuite(t, dbio.TypeDbDuckDb)
-}
+	if os.Getenv("DUCKDB_USE_ARROW") == "" {
+		os.Setenv("DUCKDB_USE_ARROW", "true")
+		testSuite(t, dbio.TypeDbDuckDb)
+		os.Setenv("DUCKDB_USE_ARROW", "false")
+	}
 
-func TestSuiteDatabaseDuckLake(t *testing.T) {
-	t.Parallel()
+	// MOTHERDUCK
+	testSuite(t, dbio.TypeDbMotherDuck)
+
+	// DUCKLAKE
 	tests := "1-17,19+" // soft-delete is not supported
 	testSuite(t, dbio.TypeDbDuckLake, tests)
 	// testSuite(t, dbio.Type("ducklake_az"), tests)
 	testSuite(t, dbio.Type("ducklake_r2"), tests)
 	testSuite(t, dbio.Type("ducklake_s3"), tests)
 }
 
-func TestSuiteDatabaseMotherDuck(t *testing.T) {
-	t.Parallel()
-	testSuite(t, dbio.TypeDbMotherDuck)
-}
-
 func TestSuiteDatabaseExasol(t *testing.T) {
 	t.Skip() // FIXME: cannot drop table, cannot create view without auto-commit
 	t.Parallel()

core/dbio/connection/connection.go

@@ -480,6 +480,47 @@ func (c *Connection) AsAPIContext(ctx context.Context, options ...AsConnOptions)
 	return c.API, nil
 }
 
+// setUseADBC turns on ADBC for supported databases when SLING_USE_ADBC is set,
+// so a whole environment can be switched over without editing every connection.
+// An explicit use_adbc on the connection always wins.
+func (c *Connection) setUseADBC() {
+
+	// adbcSupportedTypes are the database types that can be driven over ADBC.
+	// Must stay in sync with the switch in database.NewAdbcConn.
+	var adbcSupportedTypes = []dbio.Type{
+		dbio.TypeDbPostgres,
+		dbio.TypeDbSQLServer,
+		dbio.TypeDbSnowflake,
+		dbio.TypeDbSQLite,
+		dbio.TypeDbDuckDb,
+		dbio.TypeDbBigQuery,
+		dbio.TypeDbMySQL,
+		dbio.TypeDbTrino,
+	}
+
+	if !cast.ToBool(os.Getenv("SLING_USE_ADBC")) {
+		return
+	}
+
+	if _, ok := c.Data["use_adbc"]; ok {
+		return // explicitly set on the connection, leave it alone
+	}
+
+	// c.Type is not resolved yet at this point, so derive it
+	connType := c.Type
+	if connType == "" {
+		if t, ok := c.Data["type"]; ok {
+			connType = dbio.Type(cast.ToString(t))
+		} else if url := c.URL(); url != "" {
+			connType = SchemeType(url)
+		}
+	}
+
+	if g.In(connType, adbcSupportedTypes...) {
+		c.Data["use_adbc"] = true
+	}
+}
+
 func (c *Connection) setFromEnv() {
 	if c.Name == "" && strings.HasPrefix(c.URL(), "$") {
 		c.Name = strings.TrimLeft(c.URL(), "$")
@@ -513,6 +554,7 @@ func (c *Connection) ConnSetDatabase(dbName string) *Connection {
 
 func (c *Connection) setURL() (err error) {
 	c.setFromEnv()
+	c.setUseADBC()
 
 	// setIfMissing sets a default value if key is not present
 	setIfMissing := func(key string, val interface{}) {

core/dbio/database/database.go

@@ -2385,8 +2385,8 @@ func (conn *BaseConn) castBoolForSelect(srcCol iop.Column, tgtCol iop.Column) (s
 		castExpr := g.R(castFuncInt, "field", qName, "type", intType)
 		sql := `case when {col} = 'true' then 1 when {col} = 'false' then 0 else {col_as_int} end`
 		selectStr = g.R(sql, "col", qName, "col_as_int", castExpr)
-	case (srcCol.IsInteger() || srcCol.IsBool()) && tgtCol.IsString():
-		// assume bool, convert from 1/0 to true/false
+	case srcCol.IsInteger() && tgtCol.IsString():
+		// assume bool-as-int, convert from 1/0 to true/false
 		stringType := conn.GetType().GetTemplateValue("general_type_map.string")
 		if g.In(conn.GetType(), dbio.TypeDbMySQL, dbio.TypeDbMariaDB) {
 			// MySQL/MariaDB needs `CAST(column AS CHAR(length))`
@@ -2397,6 +2397,11 @@ func (conn *BaseConn) castBoolForSelect(srcCol iop.Column, tgtCol iop.Column) (s
 		castExpr := g.R(castFunc, "field", qName, "type", stringType)
 		sql := `case when {col} = 1 then 'true' when {col} = 0 then 'false' else {col_as_string} end`
 		selectStr = g.R(sql, "col", qName, "col_as_string", castExpr)
+	case srcCol.IsBool() && tgtCol.IsString():
+		// Genuine boolean: PG-family rejects `boolean = integer`, and Redshift
+		// rejects `CAST(boolean AS varchar)`. Use truthiness (no = 1 / no cast).
+		sql := `case when {col} is null then null when {col} then 'true' else 'false' end`
+		selectStr = g.R(sql, "col", qName)
 	default:
 		selectStr = qName
 	}