expression: forbid binary string to be json key (#37541)

close pingcap/tidb#37509

executor/aggfuncs/func_json_objectagg.go

@@ -79,6 +79,10 @@ func (e *jsonObjectAgg) UpdatePartialResult(sctx sessionctx.Context, rowsInGroup
 			return 0, json.ErrJSONDocumentNULLKey
 		}
 
+		if e.args[0].GetType().GetCharset() == charset.CharsetBin {
+			return 0, json.ErrInvalidJSONCharset.GenWithStackByArgs(e.args[0].GetType().GetCharset())
+		}
+
 		value, err := e.args[1].Eval(row)
 		if err != nil {
 			return 0, errors.Trace(err)

executor/aggfuncs/func_json_objectagg_test.go

@@ -56,6 +56,10 @@ func TestMergePartialResult4JsonObjectagg(t *testing.T) {
 	}
 	var argCombines [][]*types.FieldType
 	for i := 0; i < len(typeList); i++ {
+		if typeList[i].GetCharset() == charset.CharsetBin {
+			// skip because binary charset cannot be used as key.
+			continue
+		}
 		for j := 0; j < len(typeList); j++ {
 			argTypes := []*types.FieldType{typeList[i], typeList[j]}
 			argCombines = append(argCombines, argTypes)
@@ -112,6 +116,10 @@ func TestJsonObjectagg(t *testing.T) {
 	}
 	var argCombines [][]*types.FieldType
 	for i := 0; i < len(typeList); i++ {
+		if typeList[i].GetCharset() == charset.CharsetBin {
+			// skip because binary charset cannot be used as key.
+			continue
+		}
 		for j := 0; j < len(typeList); j++ {
 			argTypes := []*types.FieldType{typeList[i], typeList[j]}
 			argCombines = append(argCombines, argTypes)

expression/aggregation/base_func.go

@@ -119,7 +119,7 @@ func (a *baseFuncDesc) TypeInfer(ctx sessionctx.Context) error {
 	case ast.AggFuncJsonArrayagg:
 		a.typeInfer4JsonArrayAgg(ctx)
 	case ast.AggFuncJsonObjectAgg:
-		a.typeInfer4JsonObjectAgg(ctx)
+		return a.typeInfer4JsonObjectAgg(ctx)
 	default:
 		return errors.Errorf("unsupported agg function: %s", a.Name)
 	}
@@ -294,10 +294,11 @@ func (a *baseFuncDesc) typeInfer4JsonArrayAgg(ctx sessionctx.Context) {
 	types.SetBinChsClnFlag(a.RetTp)
 }
 
-func (a *baseFuncDesc) typeInfer4JsonObjectAgg(ctx sessionctx.Context) {
+func (a *baseFuncDesc) typeInfer4JsonObjectAgg(ctx sessionctx.Context) error {
 	a.RetTp = types.NewFieldType(mysql.TypeJSON)
 	types.SetBinChsClnFlag(a.RetTp)
 	a.Args[0] = expression.WrapWithCastAsString(ctx, a.Args[0])
+	return nil
 }
 
 func (a *baseFuncDesc) typeInfer4NumberFuncs() {

expression/builtin_json.go

@@ -22,6 +22,7 @@ import (
 
 	"github.com/pingcap/errors"
 	"github.com/pingcap/tidb/parser/ast"
+	"github.com/pingcap/tidb/parser/charset"
 	"github.com/pingcap/tidb/parser/mysql"
 	"github.com/pingcap/tidb/sessionctx"
 	"github.com/pingcap/tidb/types"
@@ -496,6 +497,9 @@ func (c *jsonObjectFunctionClass) getFunction(ctx sessionctx.Context, args []Exp
 	}
 	argTps := make([]types.EvalType, 0, len(args))
 	for i := 0; i < len(args)-1; i += 2 {
+		if args[i].GetType().EvalType() == types.ETString && args[i].GetType().GetCharset() == charset.CharsetBin {
+			return nil, json.ErrInvalidJSONCharset.GenWithStackByArgs(args[i].GetType().GetCharset())
+		}
 		argTps = append(argTps, types.ETString, types.ETJson)
 	}
 	bf, err := newBaseBuiltinFuncWithTp(ctx, c.funcName, args, types.ETJson, argTps...)

expression/integration_test.go

@@ -7449,6 +7449,20 @@ func TestIssue36358(t *testing.T) {
 	tk.MustQuery("select extract(day_microsecond from c) from t").Check(testkit.Rows("1020304050607"))
 }
 
+func TestJSONObjectWithBinaryCharset(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+	tk.MustExec("create table t(a char(20), b blob);")
+	tk.MustExec("insert into t values ('a string', 'a binary string');")
+	tk.MustExec("select json_object(a, b) from t;")
+	tk.MustExec("select json_objectagg(a, b) from t;")
+	tk.MustGetErrCode("select json_object(b, a) from t;", errno.ErrInvalidJSONCharset)
+	err := tk.QueryToErr("select json_objectagg(b, a) from t;")
+	require.Error(t, err)
+	require.Equal(t, "[json:3144]Cannot create a JSON value from a string with CHARACTER SET 'binary'.", err.Error())
+}
+
 func TestCastJSONOpaqueValueToNumeric(t *testing.T) {
 	store := testkit.CreateMockStore(t)
 	tk := testkit.NewTestKit(t, store)