dolthub/dolt#9641 - Fix BIT Overflow

enginetest/queries/script_queries.go

@@ -120,6 +120,74 @@ type ScriptTestAssertion struct {
 // Unlike other engine tests, ScriptTests must be self-contained. No other tables are created outside the definition of
 // the tests.
 var ScriptTests = []ScriptTest{
+	{
+		// Regression test for https://github.com/dolthub/dolt/issues/9641
+		Name: "bit union max1err dolt#9641",
+		SetUpScript: []string{
+			"CREATE TABLE report_card (id INT PRIMARY KEY, archived BIT(1))",
+			"INSERT INTO report_card VALUES (1, 0)",
+		},
+		Assertions: []ScriptTestAssertion{
+			{
+				// max1err
+				Query: `SELECT archived FROM report_card WHERE id = 1
+					UNION ALL  
+					SELECT 48 FROM report_card WHERE id = 1`,
+				Expected: []sql.Row{{int64(0)}, {int64(48)}},
+			},
+		},
+	},
+	{
+		// Regression test for https://github.com/dolthub/dolt/issues/9641
+		Name:    "bit union comprehensive regression test dolt#9641",
+		Dialect: "mysql",
+		SetUpScript: []string{
+			`CREATE TABLE t1 (
+				id int PRIMARY KEY,
+				name varchar(254),
+				archived bit(1) NOT NULL DEFAULT b'0',
+				archived_directly bit(1) NOT NULL DEFAULT b'0'
+			)`,
+			`CREATE TABLE t2 (
+				id int PRIMARY KEY,
+				name varchar(254),
+				archived bit(1) NOT NULL DEFAULT b'0'
+			)`,
+			"INSERT INTO t1 VALUES (1, 'Card1', b'0', b'0')",
+			"INSERT INTO t2 VALUES (2, 'Collection1', b'0')",
+		},
+		Assertions: []ScriptTestAssertion{
+			{
+				Query: `SELECT *,
+					COUNT(*) OVER () AS total_count
+				FROM (
+					SELECT
+						5 AS model_ranking,
+						id,
+						name,
+						archived,
+						archived_directly
+					FROM t1
+					WHERE archived_directly = FALSE
+
+					UNION ALL
+
+					SELECT
+						7 AS model_ranking,
+						id,
+						name,
+						archived,
+						NULL AS archived_directly
+					FROM t2
+					WHERE archived = FALSE AND id <> 1
+				) AS dummy_alias`,
+				Expected: []sql.Row{
+					{int64(5), int64(1), "Card1", uint64(0), int64(0), int64(2)},
+					{int64(7), int64(2), "Collection1", uint64(0), nil, int64(2)},
+				},
+			},
+		},
+	},
 	{
 		Name: "outer join finish unmatched right side",
 		SetUpScript: []string{

enginetest/server_engine.go

@@ -378,6 +378,16 @@ func rowIterForGoSqlRows(ctx *sql.Context, sch sql.Schema, rows *gosql.Rows) (sq
 func convertValue(ctx *sql.Context, sch sql.Schema, row sql.Row) sql.Row {
 	for i, col := range sch {
 		switch col.Type.Type() {
+		case query.Type_BIT:
+			if row[i] != nil {
+				if bytes, ok := row[i].([]byte); ok {
+					if bt, ok := col.Type.(types.BitType); ok {
+						if v, _, err := bt.Convert(ctx, bytes); err == nil {
+							row[i] = v
+						}
+					}
+				}
+			}
 		case query.Type_GEOMETRY:
 			if row[i] != nil {
 				r, _, err := types.GeometryType{}.Convert(ctx, row[i].([]byte))
@@ -562,9 +572,12 @@ func emptyRowForSchema(sch sql.Schema) ([]any, error) {
 func emptyValuePointerForType(t sql.Type) (any, error) {
 	switch t.Type() {
 	case query.Type_INT8, query.Type_INT16, query.Type_INT24, query.Type_INT64,
-		query.Type_BIT, query.Type_YEAR:
+		query.Type_YEAR:
 		var i gosql.NullInt64
 		return &i, nil
+	case query.Type_BIT:
+		var b []byte
+		return &b, nil
 	case query.Type_INT32:
 		var i gosql.NullInt32
 		return &i, nil
@@ -624,8 +637,10 @@ func schemaForRows(rows *gosql.Rows) (sql.Schema, error) {
 
 func convertGoSqlType(columnType *gosql.ColumnType) (sql.Type, error) {
 	switch strings.ToLower(columnType.DatabaseTypeName()) {
-	case "tinyint", "smallint", "mediumint", "int", "bigint", "bit":
+	case "tinyint", "smallint", "mediumint", "int", "bigint":
 		return types.Int64, nil
+	case "bit":
+		return types.MustCreateBitType(1), nil
 	case "unsigned tinyint", "unsigned smallint", "unsigned mediumint", "unsigned int", "unsigned bigint":
 		return types.Uint64, nil
 	case "float", "double":

sql/analyzer/resolve_unions.go

@@ -99,6 +99,10 @@ func finalizeUnions(ctx *sql.Context, a *Analyzer, n sql.Node, scope *plan.Scope
 		if err != nil {
 			return nil, transform.SameTree, err
 		}
+
+		// UNION can return multiple rows even when child queries use LIMIT 1, so disable Max1Row optimization
+		qFlags.Unset(sql.QFlagMax1Row)
+
 		return newN, transform.NewTree, nil
 	})
 }

sql/expression/convert.go

@@ -123,6 +123,9 @@ func GetConvertToType(l, r sql.Type) string {
 	if types.IsDecimal(l) || types.IsDecimal(r) {
 		return ConvertToDecimal
 	}
+	if types.IsBit(l) || types.IsBit(r) {
+		return ConvertToSigned
+	}
 	if types.IsUnsigned(l) && types.IsUnsigned(r) {
 		return ConvertToUnsigned
 	}

sql/plan/set_op.go

@@ -19,6 +19,7 @@ import (
 	"strings"
 
 	"github.com/dolthub/go-mysql-server/sql"
+	"github.com/dolthub/go-mysql-server/sql/types"
 )
 
 const (
@@ -100,6 +101,7 @@ func (s *SetOp) Schema() sql.Schema {
 	for i := range ls {
 		c := *ls[i]
 		if i < len(rs) {
+			c.Type = types.GeneralizeTypes(ls[i].Type, rs[i].Type)
 			c.Nullable = ls[i].Nullable || rs[i].Nullable
 		}
 		ret[i] = &c

sql/types/conversion.go

@@ -692,7 +692,6 @@ func GeneralizeTypes(a, b sql.Type) sql.Type {
 		// TODO: match blob length to max of the blob lengths
 		return LongBlob
 	}
-
 	aIsBit := IsBit(a)
 	bIsBit := IsBit(b)
 	if aIsBit && bIsBit {
@@ -705,7 +704,6 @@ func GeneralizeTypes(a, b sql.Type) sql.Type {
 	if bIsBit {
 		b = Int64
 	}
-
 	aIsYear := IsYear(a)
 	bIsYear := IsYear(b)
 	if aIsYear && bIsYear {