planner: fix the problem of using enum like 'x%' to build the wrong…

… range (pingcap#27267)

planner/core/integration_test.go

@@ -3937,3 +3937,42 @@ func (s *testIntegrationSuite) TestGroupBySetVar(c *C) {
 		res.Check(testkit.Rows(output[i].Plan...))
 	}
 }
+
+func (s *testIntegrationSuite) TestIssues27130(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec("use test")
+
+	tk.MustExec("drop table if exists t1")
+	tk.MustExec("create table t1( a enum('y','b','Abc','null'),b enum('y','b','Abc','null'),key(a));")
+	tk.MustQuery(`explain format=brief select * from t1 where a like "A%"`).Check(testkit.Rows(
+		"TableReader 8000.00 root  data:Selection",
+		"└─Selection 8000.00 cop[tikv]  like(test.t1.a, \"A%\", 92)",
+		"  └─TableFullScan 10000.00 cop[tikv] table:t1 keep order:false, stats:pseudo",
+	))
+	tk.MustQuery(`explain format=brief select * from t1 where b like "A%"`).Check(testkit.Rows(
+		"TableReader 8000.00 root  data:Selection",
+		"└─Selection 8000.00 cop[tikv]  like(test.t1.b, \"A%\", 92)",
+		"  └─TableFullScan 10000.00 cop[tikv] table:t1 keep order:false, stats:pseudo",
+	))
+
+	tk.MustExec("drop table if exists t2")
+	tk.MustExec("create table t2( a enum('y','b','Abc','null'),b enum('y','b','Abc','null'),key(a, b));")
+	tk.MustQuery(`explain format=brief select * from t2 where a like "A%"`).Check(testkit.Rows(
+		"TableReader 8000.00 root  data:Selection",
+		"└─Selection 8000.00 cop[tikv]  like(test.t2.a, \"A%\", 92)",
+		"  └─TableFullScan 10000.00 cop[tikv] table:t2 keep order:false, stats:pseudo",
+	))
+	tk.MustQuery(`explain format=brief select * from t2 where a like "A%" and b like "A%"`).Check(testkit.Rows(
+		"TableReader 8000.00 root  data:Selection",
+		"└─Selection 8000.00 cop[tikv]  like(test.t2.a, \"A%\", 92), like(test.t2.b, \"A%\", 92)",
+		"  └─TableFullScan 10000.00 cop[tikv] table:t2 keep order:false, stats:pseudo",
+	))
+
+	tk.MustExec("drop table if exists t3")
+	tk.MustExec("create table t3( a int,b enum('y','b','Abc','null'), c enum('y','b','Abc','null'),key(a, b, c));")
+	tk.MustQuery(`explain format=brief select * from t3 where a = 1 and b like "A%"`).Check(testkit.Rows(
+		"IndexReader 8.00 root  index:Selection",
+		"└─Selection 8.00 cop[tikv]  like(test.t3.b, \"A%\", 92)",
+		"  └─IndexRangeScan 10.00 cop[tikv] table:t3, index:a(a, b, c) range:[1,1], keep order:false, stats:pseudo",
+	))
+}

util/ranger/checker.go

@@ -15,6 +15,7 @@ package ranger
 
 import (
 	"github.com/pingcap/parser/ast"
+	"github.com/pingcap/parser/mysql"
 	"github.com/pingcap/tidb/expression"
 	"github.com/pingcap/tidb/types"
 	"github.com/pingcap/tidb/util/collate"
@@ -143,12 +144,22 @@ func (c *conditionChecker) checkLikeFunc(scalar *expression.ScalarFunction) bool
 			return false
 		}
 		if patternStr[i] == '%' {
+			// We currently do not support using `enum like 'xxx%'` to build range
+			// see https://github.com/pingcap/tidb/issues/27130 for more details
+			if scalar.GetArgs()[0].GetType().Tp == mysql.TypeEnum {
+				return false
+			}
 			if i != len(patternStr)-1 {
 				c.shouldReserve = true
 			}
 			break
 		}
 		if patternStr[i] == '_' {
+			// We currently do not support using `enum like 'xxx_'` to build range
+			// see https://github.com/pingcap/tidb/issues/27130 for more details
+			if scalar.GetArgs()[0].GetType().Tp == mysql.TypeEnum {
+				return false
+			}
 			c.shouldReserve = true
 			break
 		}