ddl: store default value as string when value type is binary or bit (#…

…9897)

ddl/db_integration_test.go

@@ -1430,3 +1430,13 @@ func (s *testIntegrationSuite) TestTreatOldVersionUTF8AsUTF8MB4(c *C) {
 		"  `b` varchar(50) CHARACTER SET ascii COLLATE ascii_bin DEFAULT NULL\n" +
 		") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"))
 }
+
+func (s *testIntegrationSuite) TestDefaultValueIsString(c *C) {
+	s.tk = testkit.NewTestKit(c, s.store)
+	s.tk.MustExec("use test")
+	s.tk.MustExec("drop table if exists t")
+	defer s.tk.MustExec("drop table if exists t")
+	s.tk.MustExec("create table t (a int default b'1');")
+	tbl := testGetTableByName(c, s.ctx, "test", "t")
+	c.Assert(tbl.Meta().Columns[0].DefaultValue, Equals, "1")
+}

ddl/ddl_api.go

@@ -21,6 +21,7 @@ import (
 	"bytes"
 	"context"
 	"fmt"
+	"strconv"
 	"strings"
 	"sync/atomic"
 	"time"
@@ -532,8 +533,12 @@ func getDefaultValue(ctx sessionctx.Context, colName string, c *ast.ColumnOption
 			// its raw string content here.
 			return v.GetBinaryLiteral().ToString(), nil
 		}
-		// For other kind of fields (e.g. INT), we supply its integer value so that it acts as integers.
-		return v.GetBinaryLiteral().ToInt(ctx.GetSessionVars().StmtCtx)
+		// For other kind of fields (e.g. INT), we supply its integer as string value.
+		value, err := v.GetBinaryLiteral().ToInt(ctx.GetSessionVars().StmtCtx)
+		if err != nil {
+			return nil, err
+		}
+		return strconv.FormatUint(value, 10), nil
 	}
 
 	if tp == mysql.TypeDuration {