types: convert string to MySQL BIT correctly (#21310)

executor/write_test.go

@@ -1992,6 +1992,38 @@ func (s *testSuite8) TestLoadDataMissingColumn(c *C) {
 
 }
 
+func (s *testSuite4) TestIssue18681(c *C) {
+	tk := testkit.NewTestKit(c, s.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));`
+	tk.MustExec(createSQL)
+	tk.MustExec("load data local infile '/tmp/nonexistence.csv' ignore into table load_data_test")
+	ctx := tk.Se.(sessionctx.Context)
+	ld, ok := ctx.Value(executor.LoadDataVarKey).(*executor.LoadDataInfo)
+	c.Assert(ok, IsTrue)
+	defer ctx.SetValue(executor.LoadDataVarKey, nil)
+	c.Assert(ld, NotNil)
+
+	deleteSQL := "delete from load_data_test"
+	selectSQL := "select bin(a), bin(b), bin(c), bin(d) from load_data_test;"
+	ctx.GetSessionVars().StmtCtx.DupKeyAsWarning = true
+	ctx.GetSessionVars().StmtCtx.BadNullAsWarning = true
+	ld.SetMaxRowsInBatch(20000)
+
+	sc := ctx.GetSessionVars().StmtCtx
+	originIgnoreTruncate := sc.IgnoreTruncate
+	defer func() {
+		sc.IgnoreTruncate = originIgnoreTruncate
+	}()
+	sc.IgnoreTruncate = false
+	tests := []testCase{
+		{nil, []byte("true\tfalse\t0\t1\n"), []string{"1|0|0|1"}, nil, "Records: 1  Deleted: 0  Skipped: 0  Warnings: 0"},
+	}
+	checkCases(tests, ld, c, tk, ctx, selectSQL, deleteSQL)
+	c.Assert(sc.WarningCount(), Equals, uint16(0))
+}
+
 func (s *testSuite4) TestLoadData(c *C) {
 	trivialMsg := "Records: 1  Deleted: 0  Skipped: 0  Warnings: 0"
 	tk := testkit.NewTestKit(c, s.store)

types/datum.go

@@ -1432,13 +1432,38 @@ func (d *Datum) convertToMysqlFloatYear(sc *stmtctx.StatementContext, target *Fi
 	return ret, err
 }
 
+func (d *Datum) convertStringToMysqlBit(sc *stmtctx.StatementContext) (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(sc)
+	}
+	return bitStr.ToInt(sc)
+}
+
 func (d *Datum) convertToMysqlBit(sc *stmtctx.StatementContext, target *FieldType) (Datum, error) {
 	var ret Datum
 	var uintValue uint64
 	var err error
 	switch d.k {
-	case KindString, KindBytes:
+	case KindBytes:
 		uintValue, err = BinaryLiteral(d.b).ToInt(sc)
+	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.Flen == 1 {
+			switch strings.ToLower(s) {
+			case "true", "1":
+				uintValue = 1
+			case "false", "0":
+				uintValue = 0
+			default:
+				uintValue, err = d.convertStringToMysqlBit(sc)
+			}
+		} else {
+			uintValue, err = d.convertStringToMysqlBit(sc)
+		}
 	case KindInt64:
 		// if input kind is int64 (signed), when trans to bit, we need to treat it as unsigned
 		d.k = KindUint64

types/datum_test.go

@@ -524,6 +524,29 @@ func prepareCompareDatums() ([]Datum, []Datum) {
 	return vals, vals1
 }
 
+func (ts *testDatumSuite) TestStringToMysqlBit(c *C) {
+	tests := []struct {
+		a   Datum
+		out []byte
+	}{
+		{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}},
+	}
+	sc := new(stmtctx.StatementContext)
+	sc.IgnoreTruncate = true
+	tp := NewFieldType(mysql.TypeBit)
+	tp.Flen = 1
+	for _, tt := range tests {
+		bin, err := tt.a.convertToMysqlBit(nil, tp)
+		c.Assert(err, IsNil)
+		c.Assert(bin.b, BytesEquals, tt.out)
+	}
+}
+
 func BenchmarkCompareDatum(b *testing.B) {
 	vals, vals1 := prepareCompareDatums()
 	sc := new(stmtctx.StatementContext)