support qualified name in delete where

kv/union_iter.go

@@ -102,7 +102,7 @@ func (iter *UnionIter) updateCur() {
 			} else {
 				// record from dirty comes first
 				if len(iter.dirtyIt.Value()) == 0 {
-					log.Warnf("delete a record not exists? k = %s", string(iter.dirtyIt.Key()))
+					log.Warnf("delete a record not exists? k = %q", iter.dirtyIt.Key())
 					// jump over this deletion
 					iter.dirtyNext()
 					continue

stmt/stmts/delete.go

@@ -25,6 +25,7 @@ import (
 	"github.com/pingcap/tidb/column"
 	"github.com/pingcap/tidb/context"
 	"github.com/pingcap/tidb/expression"
+	"github.com/pingcap/tidb/field"
 	"github.com/pingcap/tidb/plan"
 	"github.com/pingcap/tidb/plan/plans"
 	"github.com/pingcap/tidb/rset"
@@ -125,16 +126,15 @@ func (s *DeleteStmt) planMultiTable(ctx context.Context) (plan.Plan, error) {
 	return r, nil
 }
 
-func (s *DeleteStmt) hitWhere(ctx context.Context, t table.Table, data []interface{}) (bool, error) {
+func (s *DeleteStmt) hitWhere(ctx context.Context, fields []*field.ResultField, data []interface{}) (bool, error) {
 	if s.Where == nil {
 		return true, nil
 	}
 	m := map[interface{}]interface{}{}
-
-	// Set parameter for evaluating expression.
-	for _, col := range t.Cols() {
-		m[col.Name.L] = data[col.Offset]
+	m[expression.ExprEvalIdentFunc] = func(name string) (interface{}, error) {
+		return plans.GetIdentValue(name, fields, data, field.DefaultFieldFlag)
 	}
+
 	ok, err := expression.EvalBoolExpr(ctx, s.Where, m)
 	if err != nil {
 		return false, errors.Trace(err)
@@ -186,7 +186,7 @@ func (s *DeleteStmt) tryDeleteUsingIndex(ctx context.Context, t table.Table) (bo
 			return false, err
 		}
 		log.Infof("try delete with index id:%d, ctx:%s", handle, ctx)
-		ok, err := s.hitWhere(ctx, t, data)
+		ok, err := s.hitWhere(ctx, p.GetFields(), data)
 		if err != nil {
 			return false, errors.Trace(err)
 		}
@@ -204,6 +204,7 @@ func (s *DeleteStmt) tryDeleteUsingIndex(ctx context.Context, t table.Table) (bo
 
 // Exec implements the stmt.Statement Exec interface.
 func (s *DeleteStmt) Exec(ctx context.Context) (_ rset.Recordset, err error) {
+	// TODO: unify single from and multi from together.
 	if s.MultiTable {
 		return s.execMultiTable(ctx)
 	}
@@ -222,12 +223,14 @@ func (s *DeleteStmt) Exec(ctx context.Context) (_ rset.Recordset, err error) {
 		return nil, nil
 	}
 
+	fields := field.ColsToResultFields(t.Cols(), t.TableName().L)
+
 	var cnt uint64
 	err = t.IterRecords(ctx, t.FirstKey(), t.Cols(), func(h int64, data []interface{}, cols []*column.Col) (bool, error) {
 		if s.Limit != nil && cnt >= s.Limit.Count {
 			return false, nil
 		}
-		ok, err = s.hitWhere(ctx, t, data)
+		ok, err = s.hitWhere(ctx, fields, data)
 		if err != nil {
 			return false, errors.Trace(err)
 		}
@@ -294,6 +297,7 @@ func (s *DeleteStmt) execMultiTable(ctx context.Context) (_ rset.Recordset, err
 		if row == nil {
 			break
 		}
+
 		for _, entry := range row.RowKeys {
 			tid := entry.Tbl.TableID()
 			if _, ok := tblIDMap[tid]; !ok {
@@ -302,6 +306,7 @@ func (s *DeleteStmt) execMultiTable(ctx context.Context) (_ rset.Recordset, err
 			rowKeyMap[entry.Key] = entry.Tbl
 		}
 	}
+
 	for k, t := range rowKeyMap {
 		handle, err := util.DecodeHandleFromRowKey(k)
 		if err != nil {
@@ -316,5 +321,6 @@ func (s *DeleteStmt) execMultiTable(ctx context.Context) (_ rset.Recordset, err
 			return nil, errors.Trace(err)
 		}
 	}
+
 	return nil, nil
 }

stmt/stmts/delete_test.go

@@ -87,6 +87,10 @@ func (s *testStmtSuite) TestDelete(c *C) {
 	r = mustExec(c, s.testDB, `DELETE from test where 0;`)
 	checkResult(c, r, 0, 0)
 
+	mustExec(c, s.testDB, "insert into test values (2, 'abc')")
+	r = mustExec(c, s.testDB, `delete from test where test.id = 2 limit 1`)
+	checkResult(c, r, 1, 0)
+
 	// Select data
 	tx := mustBegin(c, s.testDB)
 	rows, err := tx.Query(s.selectSql)
@@ -157,3 +161,43 @@ func (s *testStmtSuite) TestMultiTableDelete(c *C) {
 	c.Assert(cnt, Equals, 3)
 	rows.Close()
 }
+
+func (s *testStmtSuite) TestQualifedDelete(c *C) {
+	mustExec(c, s.testDB, "drop table if exists t1")
+	mustExec(c, s.testDB, "drop table if exists t2")
+	mustExec(c, s.testDB, "create table t1 (c1 int, c2 int, index (c1))")
+	mustExec(c, s.testDB, "create table t2 (c1 int, c2 int)")
+	mustExec(c, s.testDB, "insert into t1 values (1, 1), (2, 2)")
+
+	// delete with index
+	r := mustExec(c, s.testDB, "delete from t1 where t1.c1 = 1")
+	checkResult(c, r, 1, 0)
+
+	// delete with no index
+	r = mustExec(c, s.testDB, "delete from t1 where t1.c2 = 2")
+	checkResult(c, r, 1, 0)
+
+	rows, err := s.testDB.Query("select * from t1")
+	c.Assert(err, IsNil)
+	cnt := 0
+	for rows.Next() {
+		cnt++
+	}
+	rows.Close()
+	c.Assert(cnt, Equals, 0)
+
+	_, err = s.testDB.Exec("delete from t1 as a where a.c1 = 1")
+	c.Assert(err, NotNil)
+
+	mustExec(c, s.testDB, "insert into t1 values (1, 1), (2, 2)")
+	mustExec(c, s.testDB, "insert into t2 values (2, 1), (3,1)")
+
+	r = mustExec(c, s.testDB, "delete t1, t2 from t1 join t2 where t1.c1 = t2.c2")
+	checkResult(c, r, 3, 0)
+
+	mustExec(c, s.testDB, "insert into t2 values (2, 1), (3,1)")
+	r = mustExec(c, s.testDB, "delete a, b from t1 as a join t2 as b where a.c2 = b.c1")
+	checkResult(c, r, 2, 0)
+
+	mustExec(c, s.testDB, "drop table t1, t2")
+}