expression: do not rewrite like to = if new collation is enabled (#…

…21893)
pingcap · Dec 23, 2020 · 49791bc · 49791bc
1 parent 392043a
commit 49791bc
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Showing 3 changed files with 19 additions and 6 deletions.
diff --git a/expression/integration_test.go b/expression/integration_test.go
@@ -8375,6 +8375,19 @@ func (s *testIntegrationSuite) TestIssue12205(c *C) {
 		testkit.Rows("Warning 1292 Truncated incorrect time value: '18446744072635875000'"))
 }
 
+func (s *testIntegrationSerialSuite) TestLikeWithCollation(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	collate.SetNewCollationEnabledForTest(true)
+	defer collate.SetNewCollationEnabledForTest(false)
+
+	tk.MustQuery(`select 'a' like 'A' collate utf8mb4_unicode_ci;`).Check(testkit.Rows("1"))
+	tk.MustGetErrMsg(`select 'a' collate utf8mb4_bin like 'A' collate utf8mb4_unicode_ci;`, "[expression:1270]Illegal mix of collations (utf8mb4_bin,EXPLICIT), (utf8mb4_unicode_ci,EXPLICIT), (utf8mb4_bin,NUMERIC) for operation 'like'")
+	tk.MustQuery(`select '😛' collate utf8mb4_general_ci like '😋';`).Check(testkit.Rows("1"))
+	tk.MustQuery(`select '😛' collate utf8mb4_general_ci = '😋';`).Check(testkit.Rows("1"))
+	tk.MustQuery(`select '😛' collate utf8mb4_unicode_ci like '😋';`).Check(testkit.Rows("0"))
+	tk.MustQuery(`select '😛' collate utf8mb4_unicode_ci = '😋';`).Check(testkit.Rows("1"))
+}
+
 func (s *testIntegrationSuite) TestIssue11333(c *C) {
 	defer s.cleanEnv(c)
 	tk := testkit.NewTestKit(c, s.store)

diff --git a/planner/core/expression_rewriter.go b/planner/core/expression_rewriter.go
@@ -1482,8 +1482,8 @@ func (er *expressionRewriter) patternLikeToExpression(v *ast.PatternLikeExpr) {
 	var function expression.Expression
 	fieldType := &types.FieldType{}
 	isPatternExactMatch := false
-	// Treat predicate 'like' the same way as predicate '=' when it is an exact match.
-	if patExpression, ok := er.ctxStack[l-1].(*expression.Constant); ok {
+	// Treat predicate 'like' the same way as predicate '=' when it is an exact match and new collation is not enabled.
+	if patExpression, ok := er.ctxStack[l-1].(*expression.Constant); ok && !collate.NewCollationEnabled() {
 		patString, isNull, err := patExpression.EvalString(nil, chunk.Row{})
 		if err != nil {
 			er.err = err

diff --git a/util/ranger/ranger_test.go b/util/ranger/ranger_test.go
@@ -377,14 +377,14 @@ create table t(
 		{
 			indexPos:    0,
 			exprStr:     "a LIKE 'abc'",
-			accessConds: "[eq(test.t.a, abc)]",
+			accessConds: "[like(test.t.a, abc, 92)]",
 			filterConds: "[]",
 			resultStr:   "[[\"abc\",\"abc\"]]",
 		},
 		{
 			indexPos:    0,
 			exprStr:     `a LIKE "ab\_c"`,
-			accessConds: "[eq(test.t.a, ab_c)]",
+			accessConds: "[like(test.t.a, ab\\_c, 92)]",
 			filterConds: "[]",
 			resultStr:   "[[\"ab_c\",\"ab_c\"]]",
 		},
@@ -398,14 +398,14 @@ create table t(
 		{
 			indexPos:    0,
 			exprStr:     `a LIKE '\%a'`,
-			accessConds: "[eq(test.t.a, %a)]",
+			accessConds: "[like(test.t.a, \\%a, 92)]",
 			filterConds: "[]",
 			resultStr:   `[["%a","%a"]]`,
 		},
 		{
 			indexPos:    0,
 			exprStr:     `a LIKE "\\"`,
-			accessConds: "[eq(test.t.a, \\)]",
+			accessConds: "[like(test.t.a, \\, 92)]",
 			filterConds: "[]",
 			resultStr:   "[[\"\\\",\"\\\"]]",
 		},