planner: refactor the code of buildUpdate to solve some bugs (pingcap…

…#13208)

executor/executor_test.go

@@ -1653,6 +1653,13 @@ func (s *testSuite) TestGeneratedColumnRead(c *C) {
 	result = tk.MustQuery(`SELECT * FROM test_gc_read ORDER BY a`)
 	result.Check(testkit.Rows(`10 <nil> <nil> <nil>`, `11 2 13 22`, `13 4 17 52`, `18 8 26 144`))
 
+	tk.MustExec("drop table if exists t")
+	tk.MustExec("create table t(a int)")
+	tk.MustExec("insert into t values(18)")
+	tk.MustExec("update test_gc_read set a = a+1 where a in (select a from t)")
+	result = tk.MustQuery("select * from test_gc_read order by a")
+	result.Check(testkit.Rows(`10 <nil> <nil> <nil> <nil>`, `11 2 13 22 26`, `13 4 17 52 34`, `19 8 27 152 54`))
+
 	// Test different types between generation expression and generated column.
 	tk.MustExec(`CREATE TABLE test_gc_read_cast(a VARCHAR(255), b VARCHAR(255), c INT AS (JSON_EXTRACT(a, b)), d INT AS (JSON_EXTRACT(a, b)) STORED)`)
 	tk.MustExec(`INSERT INTO test_gc_read_cast (a, b) VALUES ('{"a": "3"}', '$.a')`)

executor/update_test.go

@@ -227,3 +227,13 @@ func (s *testUpdateSuite) TestUpdateWithSubquery(c *C) {
 	tk.MustExec("update t1 set status = 'N' where status = 'F' and (id in (select id from t2 where field = 'MAIN') or id2 in (select id from t2 where field = 'main'))")
 	tk.MustQuery("select * from t1").Check(testkit.Rows("abc N abc"))
 }
+
+func (s *testUpdateSuite) TestUpdateMultiDatabaseTable(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec("use test")
+	tk.MustExec("drop database if exists test2")
+	tk.MustExec("create database test2")
+	tk.MustExec("create table t(a int, b int generated always  as (a+1) virtual)")
+	tk.MustExec("create table test2.t(a int, b int generated always  as (a+1) virtual)")
+	tk.MustExec("update t, test2.t set test.t.a=1")
+}

planner/core/logical_plan_builder.go

@@ -2323,8 +2323,6 @@ func (b *planBuilder) buildUpdateLists(tableList []*ast.TableName, list []*ast.A
 	// If columns in set list contains generated columns, raise error.
 	// And, fill virtualAssignments here; that's for generated columns.
 	virtualAssignments := make([]*ast.Assignment, 0)
-	tableAsName := make(map[*model.TableInfo][]*model.CIStr)
-	extractTableAsNameForUpdate(p, tableAsName)
 
 	for _, tn := range tableList {
 		tableInfo := tn.TableInfo
@@ -2340,12 +2338,10 @@ func (b *planBuilder) buildUpdateLists(tableList []*ast.TableName, list []*ast.A
 			if _, ok := modifyColumns[columnFullName]; ok {
 				return nil, nil, ErrBadGeneratedColumn.GenWithStackByArgs(colInfo.Name.O, tableInfo.Name.O)
 			}
-			for _, asName := range tableAsName[tableInfo] {
-				virtualAssignments = append(virtualAssignments, &ast.Assignment{
-					Column: &ast.ColumnName{Table: *asName, Name: colInfo.Name},
-					Expr:   tableVal.Cols()[i].GeneratedExpr,
-				})
-			}
+			virtualAssignments = append(virtualAssignments, &ast.Assignment{
+				Column: &ast.ColumnName{Schema: tn.Schema, Table: tn.Name, Name: colInfo.Name},
+				Expr:   tableVal.Cols()[i].GeneratedExpr,
+			})
 		}
 	}
 
@@ -2395,47 +2391,6 @@ func (b *planBuilder) buildUpdateLists(tableList []*ast.TableName, list []*ast.A
 	return newList, p, nil
 }
 
-// extractTableAsNameForUpdate extracts tables' alias names for update.
-func extractTableAsNameForUpdate(p LogicalPlan, asNames map[*model.TableInfo][]*model.CIStr) {
-	switch x := p.(type) {
-	case *DataSource:
-		alias := extractTableAlias(p)
-		if alias != nil {
-			if _, ok := asNames[x.tableInfo]; !ok {
-				asNames[x.tableInfo] = make([]*model.CIStr, 0, 1)
-			}
-			asNames[x.tableInfo] = append(asNames[x.tableInfo], alias)
-		}
-	case *LogicalProjection:
-		if !x.calculateGenCols {
-			return
-		}
-
-		ds, isDS := x.Children()[0].(*DataSource)
-		if !isDS {
-			// try to extract the DataSource below a LogicalUnionScan.
-			if us, isUS := x.Children()[0].(*LogicalUnionScan); isUS {
-				ds, isDS = us.Children()[0].(*DataSource)
-			}
-		}
-		if !isDS {
-			return
-		}
-
-		alias := extractTableAlias(x)
-		if alias != nil {
-			if _, ok := asNames[ds.tableInfo]; !ok {
-				asNames[ds.tableInfo] = make([]*model.CIStr, 0, 1)
-			}
-			asNames[ds.tableInfo] = append(asNames[ds.tableInfo], alias)
-		}
-	default:
-		for _, child := range p.Children() {
-			extractTableAsNameForUpdate(child, asNames)
-		}
-	}
-}
-
 func (b *planBuilder) buildDelete(delete *ast.DeleteStmt) (Plan, error) {
 	if b.pushTableHints(delete.TableHints) {
 		// table hints are only visible in the current DELETE statement.
@@ -2569,6 +2524,7 @@ func extractTableList(node ast.ResultSetNode, input []*ast.TableName, asName boo
 			if x.AsName.L != "" && asName {
 				newTableName := *s
 				newTableName.Name = x.AsName
+				newTableName.Schema = model.NewCIStr("")
 				input = append(input, &newTableName)
 			} else {
 				input = append(input, s)