sync_diff: support json compare (#674)

close #606

sync_diff_inspector/diff.go

@@ -446,7 +446,7 @@ func (df *Diff) consume(ctx context.Context, rangeInfo *splitter.RangeInfo) bool
 		if err != nil {
 			df.report.SetTableMeetError(schema, table, err)
 		}
-		isEqual = isEqual && isDataEqual
+		isEqual = isDataEqual
 	}
 	dml.node.State = state
 	id := rangeInfo.ChunkRange.Index

sync_diff_inspector/utils/utils.go

@@ -16,8 +16,10 @@ package utils
 import (
 	"context"
 	"database/sql"
+	"encoding/json"
 	"fmt"
 	"math"
+	"reflect"
 	"sort"
 	"strconv"
 	"strings"
@@ -533,6 +535,22 @@ func CompareData(map1, map2 map[string]*dbutil.ColumnData, orderKeyCols, columns
 			if math.Abs(num1-num2) <= 1e-6 {
 				continue
 			}
+		} else if column.FieldType.GetType() == mysql.TypeJSON {
+			if (str1 == str2) || (data1.IsNull == data2.IsNull) {
+				continue
+			}
+			var v1, v2 any
+			err := json.Unmarshal(data1.Data, &v1)
+			if err != nil {
+				return false, 0, errors.Errorf("unmarshal json %s failed, error %v", str1, err)
+			}
+			err = json.Unmarshal(data2.Data, &v2)
+			if err != nil {
+				return false, 0, errors.Errorf("unmarshal json %s failed, error %v", str2, err)
+			}
+			if reflect.DeepEqual(v1, v2) {
+				continue
+			}
 		} else {
 			if (str1 == str2) && (data1.IsNull == data2.IsNull) {
 				continue