Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

planner: fix expression rewriter wrong compare logic (#8269) #8289

Merged
merged 1 commit into from
Nov 13, 2018
Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
33 changes: 14 additions & 19 deletions planner/core/expression_rewriter.go
Original file line number Diff line number Diff line change
Expand Up @@ -169,15 +169,11 @@ type expressionRewriter struct {
}

// 1. If op are EQ or NE or NullEQ, constructBinaryOpFunctions converts (a0,a1,a2) op (b0,b1,b2) to (a0 op b0) and (a1 op b1) and (a2 op b2)
// 2. If op are LE or GE, constructBinaryOpFunctions converts (a0,a1,a2) op (b0,b1,b2) to
// `IF( (a0 op b0) EQ 0, 0,
// IF ( (a1 op b1) EQ 0, 0, a2 op b2))`
// 3. If op are LT or GT, constructBinaryOpFunctions converts (a0,a1,a2) op (b0,b1,b2) to
// 2. Else constructBinaryOpFunctions converts (a0,a1,a2) op (b0,b1,b2) to
// `IF( a0 NE b0, a0 op b0,
// IF( a1 NE b1,
// a1 op b1,
// a2 op b2)
// )`
// IF ( isNull(a0 NE b0), Null,
// IF ( a1 NE b1, a1 op b1,
// IF ( isNull(a1 NE b1), Null, a2 op b2))))`
func (er *expressionRewriter) constructBinaryOpFunction(l expression.Expression, r expression.Expression, op string) (expression.Expression, error) {
lLen, rLen := expression.GetRowLen(l), expression.GetRowLen(r)
if lLen == 1 && rLen == 1 {
Expand All @@ -198,15 +194,10 @@ func (er *expressionRewriter) constructBinaryOpFunction(l expression.Expression,
return expression.ComposeCNFCondition(er.ctx, funcs...), nil
default:
larg0, rarg0 := expression.GetFuncArg(l, 0), expression.GetFuncArg(r, 0)
var expr1, expr2, expr3 expression.Expression
if op == ast.LE || op == ast.GE {
expr1 = expression.NewFunctionInternal(er.ctx, op, types.NewFieldType(mysql.TypeTiny), larg0, rarg0)
expr1 = expression.NewFunctionInternal(er.ctx, ast.EQ, types.NewFieldType(mysql.TypeTiny), expr1, expression.Zero)
expr2 = expression.Zero
} else if op == ast.LT || op == ast.GT {
expr1 = expression.NewFunctionInternal(er.ctx, ast.NE, types.NewFieldType(mysql.TypeTiny), larg0, rarg0)
expr2 = expression.NewFunctionInternal(er.ctx, op, types.NewFieldType(mysql.TypeTiny), larg0, rarg0)
}
var expr1, expr2, expr3, expr4, expr5 expression.Expression
expr1 = expression.NewFunctionInternal(er.ctx, ast.NE, types.NewFieldType(mysql.TypeTiny), larg0, rarg0)
expr2 = expression.NewFunctionInternal(er.ctx, op, types.NewFieldType(mysql.TypeTiny), larg0, rarg0)
expr3 = expression.NewFunctionInternal(er.ctx, ast.IsNull, types.NewFieldType(mysql.TypeTiny), expr1)
var err error
l, err = expression.PopRowFirstArg(er.ctx, l)
if err != nil {
Expand All @@ -216,11 +207,15 @@ func (er *expressionRewriter) constructBinaryOpFunction(l expression.Expression,
if err != nil {
return nil, errors.Trace(err)
}
expr3, err = er.constructBinaryOpFunction(l, r, op)
expr4, err = er.constructBinaryOpFunction(l, r, op)
if err != nil {
return nil, errors.Trace(err)
}
expr5, err = expression.NewFunction(er.ctx, ast.If, types.NewFieldType(mysql.TypeTiny), expr3, expression.Null, expr4)
if err != nil {
return nil, errors.Trace(err)
}
return expression.NewFunction(er.ctx, ast.If, types.NewFieldType(mysql.TypeTiny), expr1, expr2, expr3)
return expression.NewFunction(er.ctx, ast.If, types.NewFieldType(mysql.TypeTiny), expr1, expr2, expr5)
}
}

Expand Down
60 changes: 60 additions & 0 deletions planner/core/expression_rewriter_test.go
Original file line number Diff line number Diff line change
@@ -0,0 +1,60 @@
// Copyright 2018 PingCAP, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// See the License for the specific language governing permissions and
// limitations under the License.

package core_test

import (
. "github.com/pingcap/check"
"github.com/pingcap/tidb/util/testkit"
"github.com/pingcap/tidb/util/testleak"
)

var _ = Suite(&testExpressionRewriterSuite{})

type testExpressionRewriterSuite struct {
}

func (s *testExpressionRewriterSuite) TestIfNullEliminateColName(c *C) {
defer testleak.AfterTest(c)()
store, dom, err := newStoreWithBootstrap()
c.Assert(err, IsNil)
tk := testkit.NewTestKit(c, store)
defer func() {
dom.Close()
store.Close()
}()
tk.MustExec("use test")
tk.MustExec("drop table if exists t")
tk.MustExec("create table t(a int not null, b int not null)")
rs, err := tk.Exec("select ifnull(a,b) from t")
c.Assert(err, IsNil)
fields := rs.Fields()
c.Assert(fields[0].Column.Name.L, Equals, "ifnull(a,b)")
}

func (s *testExpressionRewriterSuite) TestBinaryOpFunction(c *C) {
defer testleak.AfterTest(c)()
store, dom, err := newStoreWithBootstrap()
c.Assert(err, IsNil)
tk := testkit.NewTestKit(c, store)
defer func() {
dom.Close()
store.Close()
}()
tk.MustExec("use test")
tk.MustExec("drop table if exists t")
tk.MustExec("CREATE TABLE t(a int, b int, c int);")
tk.MustExec("INSERT INTO t VALUES (1, 2, 3), (NULL, 2, 3 ), (1, NULL, 3),(1, 2, NULL),(NULL, 2, 3+1), (1, NULL, 3+1), (1, 2+1, NULL),(NULL, 2, 3-1), (1, NULL, 3-1), (1, 2-1, NULL)")
tk.MustQuery("SELECT * FROM t WHERE (a,b,c) <= (1,2,3) order by b").Check(testkit.Rows("1 1 <nil>", "1 2 3"))
tk.MustQuery("SELECT * FROM t WHERE (a,b,c) > (1,2,3) order by b").Check(testkit.Rows("1 3 <nil>"))
}