planner: fix cannot find column bug for natural join

Signed-off-by: guo-shaoge <[email protected]>

Author: guo-shaoge

pkg/planner/core/casetest/logicalplan/logical_plan_builder_test.go

@@ -45,3 +45,11 @@ WHERE EXISTS
                GROUP BY a1.col_pk_char)) )`).Check(testkit.Rows("TableDual 0.00 root  rows:0"))
 	})
 }
+
+func TestNaturalJoinExpressionRewriter(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+	tk.MustExec("create table `mysql_1` (`col_bigint` bigint, col_numeric numeric);")
+	tk.MustQuery("select 0 from mysql_1 t1 where  exists ( select a2.col_bigint from mysql_1 a1 natural left join mysql_1 a2 where t1.col_bigint = (select distinct a2.col_bigint from  mysql_1 a2  where  ( t1.col_numeric <> '0.0330047607421875' ) ) )").Check(testkit.Rows())
+}

pkg/planner/core/logical_plan_builder.go

@@ -877,12 +877,12 @@ func (b *PlanBuilder) coalesceCommonColumns(p *logicalop.LogicalJoin, leftPlan,
 		}
 	}
 
-	schemaCols := make([]*expression.Column, len(lColumns)+len(rColumns)-commonLen)
+	schemaCols := make([]*expression.Column, len(lColumns)+len(rColumns))
 	copy(schemaCols[:len(lColumns)], lColumns)
-	copy(schemaCols[len(lColumns):], rColumns[commonLen:])
+	copy(schemaCols[len(lColumns):], rColumns)
 	names := make(types.NameSlice, len(schemaCols))
 	copy(names, lNames)
-	copy(names[len(lNames):], rNames[commonLen:])
+	copy(names[len(lNames):], rNames)
 
 	conds := make([]expression.Expression, 0, commonLen)
 	for i := range commonLen {