fix(pgdriver): return PostgreSQL DATE as a string

driver/pgdriver/column.go

@@ -51,7 +51,8 @@ func readColumnValue(rd *reader, dataType int32, dataLen int) (interface{}, erro
 	case pgTimestamptz:
 		return readTimeCol(rd, dataLen)
 	case pgDate:
-		return readTimeCol(rd, dataLen)
+		// Return a string and let the scanner to convert string to time.Time if necessary.
+		return readStringCol(rd, dataLen)
 	case pgText, pgVarchar:
 		return readStringCol(rd, dataLen)
 	case pgBytea:

internal/dbtest/db_test.go

@@ -225,6 +225,7 @@ func TestDB(t *testing.T) {
 		{testScanBytes},
 		{testPointers},
 		{testExists},
+		{testScanTimeIntoString},
 	}
 
 	testEachDB(t, func(t *testing.T, dbName string, db *bun.DB) {
@@ -886,3 +887,12 @@ func testExists(t *testing.T, db *bun.DB) {
 	require.NoError(t, err)
 	require.False(t, exists)
 }
+
+func testScanTimeIntoString(t *testing.T, db *bun.DB) {
+	ctx := context.Background()
+
+	var str string
+	err := db.NewSelect().ColumnExpr("CURRENT_TIMESTAMP").Scan(ctx, &str)
+	require.NoError(t, err)
+	require.NotZero(t, str)
+}

internal/dbtest/pg_test.go

@@ -264,7 +264,7 @@ func TestPGScanWithoutResult(t *testing.T) {
 	require.Equal(t, sql.ErrNoRows, err)
 }
 
-func TestIPNet(t *testing.T) {
+func TestPGIPNet(t *testing.T) {
 	type Model struct {
 		Network net.IPNet `bun:"type:inet"`
 	}
@@ -287,7 +287,7 @@ func TestIPNet(t *testing.T) {
 	require.Equal(t, *ipv4Net, model.Network)
 }
 
-func TestBytea(t *testing.T) {
+func TestPGBytea(t *testing.T) {
 	type Model struct {
 		Bytes []byte
 	}
@@ -306,3 +306,13 @@ func TestBytea(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, []byte("hello"), model.Bytes)
 }
+
+func TestPGDate(t *testing.T) {
+	db := pg(t)
+	defer db.Close()
+
+	var str string
+	err := db.NewSelect().ColumnExpr("'2021-09-15'::DATE").Scan(ctx, &str)
+	require.NoError(t, err)
+	require.Equal(t, "2021-09-15", str)
+}

schema/scan.go

@@ -207,6 +207,9 @@ func scanString(dest reflect.Value, src interface{}) error {
 	case []byte:
 		dest.SetString(string(src))
 		return nil
+	case time.Time:
+		dest.SetString(src.Format(time.RFC3339Nano))
+		return nil
 	}
 	return fmt.Errorf("bun: can't scan %#v into %s", src, dest.Type())
 }