Use charset literals in partial JSON expression

Signed-off-by: Matt Lord <[email protected]>

go/mysql/binlog/binlog_json.go

@@ -105,7 +105,10 @@ func ParseBinaryJSONDiff(data []byte) (sqltypes.Value, error) {
 	path := data[pos : uint64(pos)+pathLen]
 	pos += int(pathLen)
 	log.Errorf("DEBUG: json diff path: %s", string(path))
-	diff.WriteString(fmt.Sprintf("'%s', ", path))
+	// We have to specify the unicode character set for the strings we
+	// use in the expression as the connection can be using a different
+	// character set (e.g. vreplication always uses set names binary).
+	diff.WriteString(fmt.Sprintf("_utf8mb4'%s', ", path))
 
 	if opType == jsonDiffOpRemove { // No value for remove
 		diff.WriteString(")")
@@ -124,6 +127,9 @@ func ParseBinaryJSONDiff(data []byte) (sqltypes.Value, error) {
 		return sqltypes.Value{}, fmt.Errorf("cannot read JSON diff value for path %s: %w", path, err)
 	}
 	log.Errorf("DEBUG: json diff value: %v", value)
+	if value.Type() == json.TypeString {
+		diff.WriteString("_utf8mb4")
+	}
 	diff.WriteString(fmt.Sprintf("%s)", value))
 
 	return sqltypes.MakeTrusted(sqltypes.Expression, diff.Bytes()), nil

go/mysql/binlog_event_mysql56_test.go

@@ -353,7 +353,7 @@ func TestMySQL56PartialUpdateRowsEvent(t *testing.T) {
 		vals, err := ev.StringValuesForTests(tm, i)
 		require.NoError(t, err)
 		// The third column is the JSON column.
-		require.Equal(t, vals[2], `JSON_INSERT(%s, '$.role', "manager")`)
+		require.Equal(t, `JSON_INSERT(%s, _utf8mb4'$.role', _utf8mb4"manager")`, vals[2])
 		t.Logf("Rows: %v", vals)
 	}
 }

go/vt/vttablet/tabletmanager/rpc_vreplication_test.go

@@ -1753,7 +1753,7 @@ func addInvariants(dbClient *binlogplayer.MockDBClient, vreplID, sourceTabletUID
 		fmt.Sprintf("%s||0|0|Stopped|1|%s|0|0", position, workflow),
 	))
 	dbClient.AddInvariant(setSessionTZ, &sqltypes.Result{})
-	//dbClient.AddInvariant(setNames, &sqltypes.Result{})
+	dbClient.AddInvariant(setNames, &sqltypes.Result{})
 	dbClient.AddInvariant(setNetReadTimeout, &sqltypes.Result{})
 	dbClient.AddInvariant(setNetWriteTimeout, &sqltypes.Result{})
 

go/vt/vttablet/tabletmanager/vreplication/controller.go

@@ -215,6 +215,11 @@ func setDBClientSettings(dbClient binlogplayer.DBClient, workflowConfig *vttable
 	if _, err := dbClient.ExecuteFetch("set @@session.time_zone = '+00:00'", maxRows); err != nil {
 		return err
 	}
+	// Tables may have varying character sets. To ship the bits without interpreting them
+	// we set the character set to be binary.
+	if _, err := dbClient.ExecuteFetch("set names 'binary'", maxRows); err != nil {
+		return err
+	}
 	if _, err := dbClient.ExecuteFetch(fmt.Sprintf("set @@session.net_read_timeout = %v",
 		workflowConfig.NetReadTimeout), maxRows); err != nil {
 		return err

proto/binlogdata.proto

@@ -340,7 +340,7 @@ message RowChange {
   // set if the value in the after image is a partial JSON value that
   // is represented as an expression of
   // JSON_[INSERT|REPLACE|REMOVE](%s, '$.path', value) which then is
-  // used to add/update/replace a path in the JSON document. When the
+  // used to add/update/remove a path in the JSON document. When the
   // value is used the fmt directive must be replaced by the actual
   // column name of the JSON field.
   Bitmap json_partial_values = 4;