add DATE support to the appender (marcboeker#209)

Author: taniabogatsch

appender_test.go

@@ -663,6 +663,24 @@ func TestAppenderTime(t *testing.T) {
 	cleanupAppender(t, c, con, a)
 }
 
+func TestAppenderDate(t *testing.T) {
+	c, con, a := prepareAppender(t, `CREATE TABLE test (date DATE)`)
+
+	ts := time.Date(1996, time.July, 23, 11, 42, 23, 0, time.UTC)
+	require.NoError(t, a.AppendRow(ts))
+	require.NoError(t, a.Flush())
+
+	// Verify results.
+	row := sql.OpenDB(c).QueryRowContext(context.Background(), `SELECT date FROM test`)
+
+	var res time.Time
+	require.NoError(t, row.Scan(&res))
+	require.Equal(t, ts.Year(), res.Year())
+	require.Equal(t, ts.Month(), res.Month())
+	require.Equal(t, ts.Day(), res.Day())
+	cleanupAppender(t, c, con, a)
+}
+
 func TestAppenderBlob(t *testing.T) {
 	c, con, a := prepareAppender(t, `CREATE TABLE test (data BLOB)`)
 
@@ -824,6 +842,6 @@ func TestAppenderWithJSON(t *testing.T) {
 
 	require.Equal(t, len(jsonInputs), i)
 
-  require.NoError(t, res.Close())
+	require.NoError(t, res.Close())
 	cleanupAppender(t, c, con, a)
 }

appender_vector.go

@@ -13,6 +13,9 @@ import (
 	"unsafe"
 )
 
+// secondsPerDay to calculate the days since 1970-01-01.
+const secondsPerDay = 24 * 60 * 60
+
 // vector storage of a DuckDB column.
 type vector struct {
 	// The underlying DuckDB vector.
@@ -63,7 +66,7 @@ func (vec *vector) tryCast(val any) (any, error) {
 	case C.DUCKDB_TYPE_BLOB:
 		return tryPrimitiveCast[[]byte](val, reflect.TypeOf([]byte{}).String())
 	case C.DUCKDB_TYPE_TIMESTAMP, C.DUCKDB_TYPE_TIMESTAMP_S, C.DUCKDB_TYPE_TIMESTAMP_MS,
-		C.DUCKDB_TYPE_TIMESTAMP_NS, C.DUCKDB_TYPE_TIMESTAMP_TZ:
+		C.DUCKDB_TYPE_TIMESTAMP_NS, C.DUCKDB_TYPE_TIMESTAMP_TZ, C.DUCKDB_TYPE_DATE:
 		return tryPrimitiveCast[time.Time](val, reflect.TypeOf(time.Time{}).String())
 	case C.DUCKDB_TYPE_UUID:
 		return tryPrimitiveCast[UUID](val, reflect.TypeOf(UUID{}).String())
@@ -215,6 +218,8 @@ func (vec *vector) init(logicalType C.duckdb_logical_type, colIdx int) error {
 		vec.initTS(duckdbType)
 	case C.DUCKDB_TYPE_UUID:
 		vec.initUUID()
+	case C.DUCKDB_TYPE_DATE:
+		vec.initDate()
 	case C.DUCKDB_TYPE_LIST:
 		return vec.initList(logicalType, colIdx)
 	case C.DUCKDB_TYPE_STRUCT:
@@ -295,6 +300,12 @@ func (vec *vector) setTime(rowIdx C.idx_t, ticks int64) {
 	setPrimitive[C.duckdb_timestamp](vec, rowIdx, ts)
 }
 
+func (vec *vector) setDate(rowIdx C.idx_t, days int32) {
+	var date C.duckdb_date
+	date.days = C.int32_t(days)
+	setPrimitive[C.duckdb_date](vec, rowIdx, date)
+}
+
 func (vec *vector) setList(rowIdx C.idx_t, val any) {
 	if val == nil {
 		vec.setNull(rowIdx)
@@ -384,6 +395,21 @@ func (vec *vector) initUUID() {
 	vec.duckdbType = C.DUCKDB_TYPE_UUID
 }
 
+func (vec *vector) initDate() {
+	vec.fn = func(vec *vector, rowIdx C.idx_t, val any) {
+		if val == nil {
+			vec.setNull(rowIdx)
+			return
+		}
+
+		v := val.(time.Time)
+		// Days since 1970-01-01.
+		days := int32(v.UTC().Unix() / secondsPerDay)
+		vec.setDate(rowIdx, days)
+	}
+	vec.duckdbType = C.DUCKDB_TYPE_DATE
+}
+
 func (vec *vector) initList(logicalType C.duckdb_logical_type, colIdx int) error {
 	// Get the child vector type.
 	childType := C.duckdb_list_type_child_type(logicalType)

types.go

@@ -15,7 +15,6 @@ import (
 
 var unsupportedAppenderTypeMap = map[C.duckdb_type]string{
 	C.DUCKDB_TYPE_INVALID:  "INVALID",
-	C.DUCKDB_TYPE_DATE:     "DATE",
 	C.DUCKDB_TYPE_TIME:     "TIME",
 	C.DUCKDB_TYPE_INTERVAL: "INTERVAL",
 	C.DUCKDB_TYPE_HUGEINT:  "HUGEINT",