fix the issue that the default value for BIT is wrong

Signed-off-by: Yang Keao <[email protected]>

pkg/ddl/add_column.go

@@ -1225,6 +1225,23 @@ func checkColumnDefaultValue(ctx exprctx.BuildContext, col *table.Column, value
 			}
 		}
 	}
+	if value != nil && col.GetType() == mysql.TypeBit {
+		v, ok := value.(string)
+		if !ok {
+			return hasDefaultValue, value, types.ErrInvalidDefault.GenWithStackByArgs(col.Name.O)
+		}
+
+		uintVal, err := types.BinaryLiteral(v).ToInt(ctx.GetEvalCtx().TypeCtx())
+		if err != nil {
+			return hasDefaultValue, value, types.ErrInvalidDefault.GenWithStackByArgs(col.Name.O)
+		}
+		if col.GetFlen() >= 64 || col.GetFlen() <= 0 {
+			return hasDefaultValue, value, types.ErrInvalidDefault.GenWithStackByArgs(col.Name.O)
+		}
+		if col.GetFlen() < 64 && uintVal >= 1<<(uint64(col.GetFlen())) {
+			return hasDefaultValue, value, types.ErrInvalidDefault.GenWithStackByArgs(col.Name.O)
+		}
+	}
 	return hasDefaultValue, value, nil
 }
 

pkg/executor/test/writetest/write_test.go

@@ -230,13 +230,13 @@ func TestIssue18681(t *testing.T) {
 	tk := testkit.NewTestKit(t, store)
 	tk.MustExec("use test")
 	createSQL := `drop table if exists load_data_test;
-		create table load_data_test (a bit(1),b bit(1),c bit(1),d bit(1));`
+		create table load_data_test (a bit(1),b bit(1),c bit(1),d bit(1),e bit(32),f bit(1));`
 	tk.MustExec(createSQL)
 	loadSQL := "load data local infile '/tmp/nonexistence.csv' ignore into table load_data_test"
 	ctx := tk.Session().(sessionctx.Context)
 
 	deleteSQL := "delete from load_data_test"
-	selectSQL := "select bin(a), bin(b), bin(c), bin(d) from load_data_test;"
+	selectSQL := "select bin(a), bin(b), bin(c), bin(d), bin(e), bin(f) from load_data_test;"
 	levels := ctx.GetSessionVars().StmtCtx.ErrLevels()
 	levels[errctx.ErrGroupDupKey] = errctx.LevelWarn
 	levels[errctx.ErrGroupBadNull] = errctx.LevelWarn
@@ -248,7 +248,7 @@ func TestIssue18681(t *testing.T) {
 	}()
 	sc.SetTypeFlags(oldTypeFlags.WithIgnoreTruncateErr(true))
 	tests := []testCase{
-		{[]byte("true\tfalse\t0\t1\n"), []string{"1|0|0|1"}, "Records: 1  Deleted: 0  Skipped: 0  Warnings: 0"},
+		{[]byte("true\tfalse\t0\t1\tb'1'\tb'1'\n"), []string{"1|1|1|1|1100010001001110011000100100111|1"}, "Records: 1  Deleted: 0  Skipped: 0  Warnings: 5"},
 	}
 	checkCases(tests, loadSQL, t, tk, ctx, selectSQL, deleteSQL)
 	require.Equal(t, uint16(0), sc.WarningCount())

pkg/types/datum.go

@@ -1705,38 +1705,13 @@ func (d *Datum) ConvertToMysqlYear(ctx Context, target *FieldType) (Datum, error
 	return ret, errors.Trace(err)
 }
 
-func (d *Datum) convertStringToMysqlBit(ctx Context) (uint64, error) {
-	bitStr, err := ParseBitStr(BinaryLiteral(d.b).ToString())
-	if err != nil {
-		// It cannot be converted to bit type, so we need to convert it to int type.
-		return BinaryLiteral(d.b).ToInt(ctx)
-	}
-	return bitStr.ToInt(ctx)
-}
-
 func (d *Datum) convertToMysqlBit(ctx Context, target *FieldType) (Datum, error) {
 	var ret Datum
 	var uintValue uint64
 	var err error
 	switch d.k {
-	case KindBytes:
+	case KindString, KindBytes:
 		uintValue, err = BinaryLiteral(d.b).ToInt(ctx)
-	case KindString:
-		// For single bit value, we take string like "true", "1" as 1, and "false", "0" as 0,
-		// this behavior is not documented in MySQL, but it behaves so, for more information, see issue #18681
-		s := BinaryLiteral(d.b).ToString()
-		if target.GetFlen() == 1 {
-			switch strings.ToLower(s) {
-			case "true", "1":
-				uintValue = 1
-			case "false", "0":
-				uintValue = 0
-			default:
-				uintValue, err = d.convertStringToMysqlBit(ctx)
-			}
-		} else {
-			uintValue, err = d.convertStringToMysqlBit(ctx)
-		}
 	case KindInt64:
 		// if input kind is int64 (signed), when trans to bit, we need to treat it as unsigned
 		d.k = KindUint64

pkg/types/datum_test.go

@@ -517,22 +517,35 @@ func prepareCompareDatums() ([]Datum, []Datum) {
 
 func TestStringToMysqlBit(t *testing.T) {
 	tests := []struct {
-		a   Datum
-		out []byte
+		a         Datum
+		out       []byte
+		flen      int
+		truncated bool
 	}{
-		{NewStringDatum("true"), []byte{1}},
-		{NewStringDatum("false"), []byte{0}},
-		{NewStringDatum("1"), []byte{1}},
-		{NewStringDatum("0"), []byte{0}},
-		{NewStringDatum("b'1'"), []byte{1}},
-		{NewStringDatum("b'0'"), []byte{0}},
-	}
-	tp := NewFieldType(mysql.TypeBit)
-	tp.SetFlen(1)
+		{NewStringDatum("true"), []byte{1}, 1, true},
+		{NewStringDatum("true"), []byte{0x74, 0x72, 0x75, 0x65}, 32, false},
+		{NewStringDatum("false"), []byte{0x1}, 1, true},
+		{NewStringDatum("false"), []byte{0x66, 0x61, 0x6c, 0x73, 0x65}, 40, false},
+		{NewStringDatum("1"), []byte{1}, 1, true},
+		{NewStringDatum("1"), []byte{0x31}, 8, false},
+		{NewStringDatum("0"), []byte{1}, 1, true},
+		{NewStringDatum("0"), []byte{0x30}, 8, false},
+		{NewStringDatum("b'1'"), []byte{0x62, 0x27, 0x31, 0x27}, 32, false},
+		{NewStringDatum("b'0'"), []byte{0x62, 0x27, 0x30, 0x27}, 32, false},
+	}
 	for _, tt := range tests {
-		bin, err := tt.a.convertToMysqlBit(DefaultStmtNoWarningContext, tp)
-		require.NoError(t, err)
-		require.Equal(t, tt.out, bin.b)
+		t.Run(fmt.Sprintf("%s %d %t", tt.a.GetString(), tt.flen, tt.truncated), func(t *testing.T) {
+			tp := NewFieldType(mysql.TypeBit)
+			tp.SetFlen(tt.flen)
+
+			bin, err := tt.a.convertToMysqlBit(DefaultStmtNoWarningContext, tp)
+			if tt.truncated {
+				require.Contains(t, err.Error(), "Data Too Long")
+			} else {
+				require.NoError(t, err)
+			}
+			require.Equal(t, tt.out, bin.b)
+		})
 	}
 }
 

tests/integrationtest/r/ddl/column.result

@@ -84,3 +84,11 @@ t	CREATE TABLE `t` (
   `a` decimal(10,0) DEFAULT NULL,
   `b` decimal(10,0) DEFAULT NULL
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin
+drop table if exists t;
+create table t(a bit(2) default b'111');
+Error 1067 (42000): Invalid default value for 'a'
+create table t(a bit(3) default b'111');
+drop table t;
+create table t(a bit(3) default b'000111');
+drop table t;
+create table t(a bit(32) default b'1111111111111111111111111111111');

tests/integrationtest/r/table/tables.result

@@ -24,3 +24,9 @@ select count(distinct(_tidb_rowid>>48)) from shard_t;
 count(distinct(_tidb_rowid>>48))
 3
 set @@tidb_shard_allocate_step=default;
+drop table if exists t;
+create table t(a bit(32) default b'1100010001001110011000100100111');
+insert into t values ();
+select hex(a) from t;
+hex(a)
+62273127

tests/integrationtest/t/ddl/column.test

@@ -44,3 +44,13 @@ alter table t1 add column d date default '2024-10';
 drop table if exists t;
 create table t(a decimal(0,0), b decimal(0));
 show create table t;
+
+# TestTooLongDefaultValueForBit
+drop table if exists t;
+-- error 1067
+create table t(a bit(2) default b'111');
+create table t(a bit(3) default b'111');
+drop table t;
+create table t(a bit(3) default b'000111');
+drop table t;
+create table t(a bit(32) default b'1111111111111111111111111111111');

tests/integrationtest/t/table/tables.test

@@ -22,3 +22,9 @@ insert into shard_t values (12);
 select count(distinct(_tidb_rowid>>48)) from shard_t;
 
 set @@tidb_shard_allocate_step=default;
+
+# TestInsertBitDefaultValue
+drop table if exists t;
+create table t(a bit(32) default b'1100010001001110011000100100111');
+insert into t values ();
+select hex(a) from t;