expression_filter(dm): fix append update filter for non-update item (#…

…7851) (#7907) close #7831
pingcap · Jan 18, 2023 · 4432cb5 · 4432cb5
1 parent 2cbcba3
commit 4432cb5
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Showing 5 changed files with 22 additions and 5 deletions.
diff --git a/dm/syncer/expr_filter_group.go b/dm/syncer/expr_filter_group.go
@@ -114,6 +114,9 @@ func (g *ExprFilterGroup) GetUpdateExprs(table *filter.Table, ti *model.TableInf
 
 	if _, ok := g.hasUpdateFilter[tableID]; ok {
 		for _, c := range g.configs[tableID] {
+			if c.UpdateOldValueExpr == "" && c.UpdateNewValueExpr == "" {
+				continue
+			}
 			if c.UpdateOldValueExpr != "" {
 				expr, err := getSimpleExprOfTable(g.tidbCtx, c.UpdateOldValueExpr, ti, g.logCtx.L())
 				if err != nil {

diff --git a/dm/syncer/expr_filter_group_test.go b/dm/syncer/expr_filter_group_test.go
@@ -497,8 +497,13 @@ create table t (
 	for i, c := range cases {
 		t.Logf("case #%d", i)
 		g := NewExprFilterGroup(tcontext.Background(), sessCtx, []*config.ExpressionFilter{c})
-		oldExprs, newExprs, err := g.GetUpdateExprs(table, tableInfo)
-		require.NoError(t, err)
+		oldExprs, newExprs, err2 := g.GetUpdateExprs(table, tableInfo)
+		require.NoError(t, err2)
 		require.Equal(t, len(oldExprs), len(newExprs))
 	}
+	g := NewExprFilterGroup(tcontext.Background(), sessCtx, cases)
+	oldExprs, newExprs, err := g.GetUpdateExprs(table, tableInfo)
+	require.NoError(t, err)
+	require.Equal(t, len(oldExprs), len(newExprs))
+	require.Len(t, oldExprs, 3)
 }
diff --git a/dm/tests/expression_filter/conf/dm-task2.yaml b/dm/tests/expression_filter/conf/dm-task2.yaml
@@ -13,6 +13,7 @@ mysql-instances:
     black-white-list: "instance"
     expression-filters:
       - "even_c"
+      - "always_false"
       - "future_date"
       - "pythagorean"
       - "update_old_lt_100"
@@ -26,6 +27,11 @@ expression-filter:
     schema: "expr_filter"
     table: "t2"
     insert-value-expr: "c % 2 = 0"
+  always_false:
+    schema: "expr_filter"
+    table: "t2"
+    update-old-value-expr: "1 = 0"
+    update-new-value-expr: "1 = 0"
   future_date:
     schema: "expr_filter"
     table: "t3"

diff --git a/dm/tests/expression_filter/data/db1.increment2.sql b/dm/tests/expression_filter/data/db1.increment2.sql
@@ -10,7 +10,8 @@ alter table t2 drop column c;
 insert into t2 (id, should_skip) values (5, 0), (6, 0);
 -- test filter become valid again, and the checking column is a generated column
 alter table t2 add column c int as (id + 1);
-insert into t2 (id, should_skip, d) values (7, 1, 100), (8, 0, 200);
+insert into t2 (id, should_skip, d) values (7, 1, 100), (8, 0, 200), (10, 2, 300);
+update t2 set should_skip = 0 where id = 10;
 
 -- test a new created table
 create table t3 (id int primary key,

diff --git a/dm/tests/expression_filter/run.sh b/dm/tests/expression_filter/run.sh
@@ -40,8 +40,10 @@ function complex_behaviour() {
 		"\"result\": true" 2 \
 		"\"synced\": true" 1
 
-	run_sql_tidb "select count(1) from expr_filter.t2"
-	check_contains "count(1): 5"
+	run_sql_tidb "select count(0) from expr_filter.t2"
+	check_contains "count(0): 6"
+	run_sql_tidb "select count(1) from expr_filter.t2 where should_skip = 0"
+	check_contains "count(1): 6"
 	run_sql_tidb "select count(2) from expr_filter.t2 where should_skip = 1"
 	check_contains "count(2): 0"