fix(kingbase): return time columns as time of day

agents/drivers/kingbase-go/main.go

@@ -1688,6 +1688,12 @@ func normalizeValue(value any, columnTypeName string) any {
 		}
 		return map[string]string{"$binary": base64.StdEncoding.EncodeToString(typed)}
 	case time.Time:
+		// A "time" column holds a time of day and no date. gokb decodes one into a
+		// time.Time on Go's zero date, so formatting a date part shows every time of
+		// day as 0000-01-01T<time> (issue #12188).
+		if isKingbaseTimeOnlyType(columnTypeName) {
+			return typed.Format("15:04:05.999999999")
+		}
 		// KingBase "timestamp"/"date" columns are wall-clock values with no timezone
 		// meaning; the gokb driver decodes them into a time.Time labeled with the
 		// process-local zone, which is not a real UTC instant. Formatting those with
@@ -1710,15 +1716,29 @@ func normalizeValue(value any, columnTypeName string) any {
 }
 
 func isKingbaseTimezoneLessDateTime(columnTypeName string) bool {
-	normalized := strings.ToUpper(strings.ReplaceAll(strings.TrimSpace(columnTypeName), " ", ""))
-	switch normalized {
-	case "DATE", "TIMESTAMP", "TIME":
+	switch normalizedKingbaseColumnType(columnTypeName) {
+	case "DATE", "TIMESTAMP":
 		return true
 	default:
 		return false
 	}
 }
 
+// isKingbaseTimeOnlyType matches the type names a "time" column can carry: the
+// driver's own name (`DatabaseTypeName`) and the information_schema spelling.
+func isKingbaseTimeOnlyType(columnTypeName string) bool {
+	switch normalizedKingbaseColumnType(columnTypeName) {
+	case "TIME", "TIMEWITHOUTTIMEZONE":
+		return true
+	default:
+		return false
+	}
+}
+
+func normalizedKingbaseColumnType(columnTypeName string) string {
+	return strings.ToUpper(strings.ReplaceAll(strings.TrimSpace(columnTypeName), " ", ""))
+}
+
 func isTextBytes(value []byte) bool {
 	for _, char := range value {
 		if char == 0 || char < 0x09 || char > 0x0d && char < 0x20 {

agents/drivers/kingbase-go/main_test.go

@@ -4936,7 +4936,7 @@ func containsString(values []string, target string) bool {
 }
 
 // Regression test for https://github.com/t8y2/dbx/issues/7681: a timezone-less
-// "timestamp"/"date"/"time" column must not be labeled as an absolute UTC
+// "timestamp"/"date" column must not be labeled as an absolute UTC
 // instant (RFC3339Nano with a "Z"/offset suffix), or clients that convert it
 // to a display timezone will double-apply the shift.
 func TestNormalizeValueKingbaseTimezoneLessDateTime(t *testing.T) {
@@ -4944,7 +4944,7 @@ func TestNormalizeValueKingbaseTimezoneLessDateTime(t *testing.T) {
 	// the process-local zone, which is not a real UTC instant.
 	wallClock := time.Date(2026, time.January, 30, 10, 0, 3, 0, time.UTC)
 
-	for _, columnType := range []string{"TIMESTAMP", "timestamp", "DATE", "TIME"} {
+	for _, columnType := range []string{"TIMESTAMP", "timestamp", "DATE"} {
 		got := normalizeValue(wallClock, columnType)
 		want := "2026-01-30T10:00:03"
 		gotStr, ok := got.(string)
@@ -4967,6 +4967,24 @@ func TestNormalizeValueKingbaseTimezoneLessDateTime(t *testing.T) {
 	}
 }
 
+// Regression test for https://github.com/t8y2/dbx/issues/12188: gokb decodes a
+// "time" column into a time.Time on Go's zero date, so the date part must not
+// reach the client. Showing it rendered every time of day as 0000-01-01T17:19:34.
+func TestNormalizeValueKingbaseTimeColumnKeepsTimeOfDay(t *testing.T) {
+	timeOfDay := time.Date(0, time.January, 1, 17, 19, 34, 0, time.UTC)
+
+	for _, columnType := range []string{"TIME", "time", "time without time zone"} {
+		got := normalizeValue(timeOfDay, columnType)
+		gotStr, ok := got.(string)
+		if !ok {
+			t.Fatalf("columnType=%s: expected a string, got %#v", columnType, got)
+		}
+		if gotStr != "17:19:34" {
+			t.Fatalf("columnType=%s: got %q, want %q", columnType, gotStr, "17:19:34")
+		}
+	}
+}
+
 func TestCatalogColumnsPreservesJsonAndJsonbTypes(t *testing.T) {
 	state := &metadataDriverState{query: func(query string) (driver.Rows, error) {
 		if !strings.Contains(query, "WHEN t.typname = 'json' THEN 'json'") ||