planner: forbiden nested view creation (pingcap#15420) (pingcap#15424)

executor/ddl_test.go

@@ -252,6 +252,15 @@ func (s *testSuite3) TestCreateView(c *C) {
 	tk.MustExec("drop view v")
 	tk.MustExec("create view v as (select * from t1 union select * from t2)")
 	tk.MustExec("drop view v")
+
+	// Test for create nested view.
+	tk.MustExec("create table test_v_nested(a int)")
+	tk.MustExec("create definer='root'@'localhost' view v_nested as select * from test_v_nested")
+	tk.MustExec("create definer='root'@'localhost' view v_nested2 as select * from v_nested")
+	_, err = tk.Exec("create or replace definer='root'@'localhost' view v_nested as select * from v_nested2")
+	c.Assert(terror.ErrorEqual(err, plannercore.ErrNoSuchTable), IsTrue)
+	tk.MustExec("drop table test_v_nested")
+	tk.MustExec("drop view v_nested, v_nested2")
 }
 
 func (s *testSuite3) TestCreateViewWithOverlongColName(c *C) {

planner/core/errors.go

@@ -125,6 +125,7 @@ var (
 	ErrWindowNoRedefineOrderBy         = terror.ClassOptimizer.New(codeWindowNoRedefineOrderBy, mysql.MySQLErrName[mysql.ErrWindowNoRedefineOrderBy])
 	ErrWindowDuplicateName             = terror.ClassOptimizer.New(codeWindowDuplicateName, mysql.MySQLErrName[mysql.ErrWindowDuplicateName])
 	ErrPartitionClauseOnNonpartitioned = terror.ClassOptimizer.New(codePartitionClauseOnNonpartitioned, mysql.MySQLErrName[mysql.ErrPartitionClauseOnNonpartitioned])
+	ErrNoSuchTable                     = terror.ClassOptimizer.New(mysql.ErrNoSuchTable, mysql.MySQLErrName[mysql.ErrNoSuchTable])
 	errTooBigPrecision                 = terror.ClassExpression.New(mysql.ErrTooBigPrecision, mysql.MySQLErrName[mysql.ErrTooBigPrecision])
 	ErrDBaccessDenied                  = terror.ClassOptimizer.New(mysql.ErrDBaccessDenied, mysql.MySQLErrName[mysql.ErrDBaccessDenied])
 	ErrTableaccessDenied               = terror.ClassOptimizer.New(mysql.ErrTableaccessDenied, mysql.MySQLErrName[mysql.ErrTableaccessDenied])

planner/core/logical_plan_builder.go

@@ -2234,6 +2234,9 @@ func (b *PlanBuilder) buildDataSource(ctx context.Context, tn *ast.TableName) (L
 	b.visitInfo = appendVisitInfo(b.visitInfo, mysql.SelectPriv, dbName.L, tableInfo.Name.L, "", authErr)
 
 	if tableInfo.IsView() {
+		if b.capFlag&collectUnderlyingViewName != 0 {
+			b.underlyingViewNames.Insert(dbName.L + "." + tn.Name.L)
+		}
 		return b.BuildDataSourceFromView(ctx, dbName, tableInfo)
 	}
 

planner/core/planbuilder.go

@@ -41,6 +41,7 @@ import (
 	"github.com/pingcap/tidb/util/chunk"
 	"github.com/pingcap/tidb/util/logutil"
 	"github.com/pingcap/tidb/util/ranger"
+	"github.com/pingcap/tidb/util/set"
 	"go.uber.org/zap"
 )
 
@@ -169,6 +170,9 @@ const (
 	// canExpandAST indicates whether the origin AST can be expanded during plan
 	// building. ONLY used for `CreateViewStmt` now.
 	canExpandAST
+	// collectUnderlyingViewName indicates whether to collect the underlying
+	// view names of a CreateViewStmt during plan building.
+	collectUnderlyingViewName
 )
 
 // PlanBuilder builds Plan from an ast.Node.
@@ -203,6 +207,8 @@ type PlanBuilder struct {
 
 	// SelectLock need this information to locate the lock on partitions.
 	partitionedTable []table.PartitionedTable
+	// CreateView needs this information to check whether exists nested view.
+	underlyingViewNames set.StringSet
 }
 
 // GetVisitInfo gets the visitInfo of the PlanBuilder.
@@ -2195,13 +2201,19 @@ func (b *PlanBuilder) buildDDL(ctx context.Context, node ast.DDLNode) (Plan, err
 		}
 	case *ast.CreateViewStmt:
 		b.capFlag |= canExpandAST
+		b.capFlag |= collectUnderlyingViewName
 		defer func() {
 			b.capFlag &= ^canExpandAST
+			b.capFlag &= ^collectUnderlyingViewName
 		}()
+		b.underlyingViewNames = set.NewStringSet()
 		plan, err := b.Build(ctx, v.Select)
 		if err != nil {
 			return nil, err
 		}
+		if b.underlyingViewNames.Exist(v.ViewName.Schema.L + "." + v.ViewName.Name.L) {
+			return nil, ErrNoSuchTable.GenWithStackByArgs(v.ViewName.Schema.O, v.ViewName.Name.O)
+		}
 		schema := plan.Schema()
 		if v.Cols == nil {
 			adjustOverlongViewColname(plan.(LogicalPlan))