Add types to Go SQL driver

This adds two interfaces, one for the type names and one for nullable to
the Go SQL driver for Vitess. This is missing and means this type
information can't be easily retrieved from result sets.

Signed-off-by: Dirkjan Bussink <[email protected]>

go/vt/vitessdriver/rows.go

@@ -119,3 +119,80 @@ func (ri *rows) ColumnTypeScanType(index int) reflect.Type {
 		return typeUnknown
 	}
 }
+
+func (ri *rows) ColumnTypeDatabaseTypeName(index int) string {
+	field := ri.qr.Fields[index]
+	switch field.GetType() {
+	case query.Type_INT8:
+		return "TINYINT"
+	case query.Type_UINT8:
+		return "UNSIGNED TINYINT"
+	case query.Type_INT16:
+		return "SMALLINT"
+	case query.Type_UINT16:
+		return "UNSIGNED SMALLINT"
+	case query.Type_YEAR:
+		return "YEAR"
+	case query.Type_INT24:
+		return "MEDIUMINT"
+	case query.Type_UINT24:
+		return "UNSIGNED MEDIUMINT"
+	case query.Type_INT32:
+		return "INT"
+	case query.Type_UINT32:
+		return "UNSIGNED INT"
+	case query.Type_INT64:
+		return "BIGINT"
+	case query.Type_UINT64:
+		return "UNSIGNED BIGINT"
+	case query.Type_FLOAT32:
+		return "FLOAT"
+	case query.Type_FLOAT64:
+		return "DOUBLE"
+	case query.Type_DECIMAL:
+		return "DECIMAL"
+	case query.Type_VARCHAR:
+		return "VARCHAR"
+	case query.Type_TEXT:
+		return "TEXT"
+	case query.Type_BLOB:
+		return "BLOB"
+	case query.Type_VARBINARY:
+		return "VARBINARY"
+	case query.Type_CHAR:
+		return "CHAR"
+	case query.Type_BINARY:
+		return "BINARY"
+	case query.Type_BIT:
+		return "BIT"
+	case query.Type_ENUM:
+		return "ENUM"
+	case query.Type_SET:
+		return "SET"
+	case query.Type_HEXVAL:
+		return "VARBINARY"
+	case query.Type_HEXNUM:
+		return "VARBINARY"
+	case query.Type_BITNUM:
+		return "VARBINARY"
+	case query.Type_GEOMETRY:
+		return "GEOMETRY"
+	case query.Type_JSON:
+		return "JSON"
+	case query.Type_TIMESTAMP:
+		return "TIMESTAMP"
+	case query.Type_DATE:
+		return "DATE"
+	case query.Type_TIME:
+		return "TIME"
+	case query.Type_DATETIME:
+		return "DATETIME"
+	default:
+		return ""
+	}
+}
+
+func (ri *rows) ColumnTypeNullable(index int) (nullable, ok bool) {
+	field := ri.qr.Fields[index]
+	return field.GetFlags()&uint32(query.MySqlFlag_NOT_NULL_FLAG) == 0, true
+}

go/vt/vitessdriver/rows_test.go

@@ -226,3 +226,123 @@ func TestColumnTypeScanType(t *testing.T) {
 		assert.Equal(t, ri.ColumnTypeScanType(i), wantTypes[i], fmt.Sprintf("unexpected type %v, wanted %v", ri.ColumnTypeScanType(i), wantTypes[i]))
 	}
 }
+
+// Test that the ColumnTypeScanType function returns the correct reflection type for each
+// sql type. The sql type in turn comes from a table column's type.
+func TestColumnTypeDatabaseTypeName(t *testing.T) {
+	var r = sqltypes.Result{
+		Fields: []*querypb.Field{
+			{
+				Name: "field1",
+				Type: sqltypes.Int8,
+			},
+			{
+				Name: "field2",
+				Type: sqltypes.Uint8,
+			},
+			{
+				Name: "field3",
+				Type: sqltypes.Int16,
+			},
+			{
+				Name: "field4",
+				Type: sqltypes.Uint16,
+			},
+			{
+				Name: "field5",
+				Type: sqltypes.Int24,
+			},
+			{
+				Name: "field6",
+				Type: sqltypes.Uint24,
+			},
+			{
+				Name: "field7",
+				Type: sqltypes.Int32,
+			},
+			{
+				Name: "field8",
+				Type: sqltypes.Uint32,
+			},
+			{
+				Name: "field9",
+				Type: sqltypes.Int64,
+			},
+			{
+				Name: "field10",
+				Type: sqltypes.Uint64,
+			},
+			{
+				Name: "field11",
+				Type: sqltypes.Float32,
+			},
+			{
+				Name: "field12",
+				Type: sqltypes.Float64,
+			},
+			{
+				Name: "field13",
+				Type: sqltypes.VarBinary,
+			},
+			{
+				Name: "field14",
+				Type: sqltypes.Datetime,
+			},
+		},
+	}
+
+	ri := newRows(&r, &converter{}).(driver.RowsColumnTypeDatabaseTypeName)
+	defer ri.Close()
+
+	wantTypes := []string{
+		"TINYINT",
+		"UNSIGNED TINYINT",
+		"SMALLINT",
+		"UNSIGNED SMALLINT",
+		"MEDIUMINT",
+		"UNSIGNED MEDIUMINT",
+		"INT",
+		"UNSIGNED INT",
+		"BIGINT",
+		"UNSIGNED BIGINT",
+		"FLOAT",
+		"DOUBLE",
+		"VARBINARY",
+		"DATETIME",
+	}
+
+	for i := 0; i < len(wantTypes); i++ {
+		assert.Equal(t, ri.ColumnTypeDatabaseTypeName(i), wantTypes[i], fmt.Sprintf("unexpected type %v, wanted %v", ri.ColumnTypeDatabaseTypeName(i), wantTypes[i]))
+	}
+}
+
+// Test that the ColumnTypeScanType function returns the correct reflection type for each
+// sql type. The sql type in turn comes from a table column's type.
+func TestColumnTypeNullable(t *testing.T) {
+	var r = sqltypes.Result{
+		Fields: []*querypb.Field{
+			{
+				Name:  "field1",
+				Type:  sqltypes.Int64,
+				Flags: uint32(querypb.MySqlFlag_NOT_NULL_FLAG),
+			},
+			{
+				Name: "field2",
+				Type: sqltypes.Int64,
+			},
+		},
+	}
+
+	ri := newRows(&r, &converter{}).(driver.RowsColumnTypeNullable)
+	defer ri.Close()
+
+	nullable := []bool{
+		false,
+		true,
+	}
+
+	for i := 0; i < len(nullable); i++ {
+		null, _ := ri.ColumnTypeNullable(i)
+		assert.Equal(t, null, nullable[i], fmt.Sprintf("unexpected type %v, wanted %v", null, nullable[i]))
+	}
+}