planner: update's select should not change the output columns (#12476)

pingcap · Sep 29, 2019 · 6169553 · 6169553
1 parent 41ac571
commit 6169553
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Showing 2 changed files with 13 additions and 0 deletions.
diff --git a/planner/core/logical_plan_builder.go b/planner/core/logical_plan_builder.go
@@ -2743,12 +2743,21 @@ func (b *PlanBuilder) buildUpdate(ctx context.Context, update *ast.UpdateStmt) (
 		b.visitInfo = appendVisitInfo(b.visitInfo, mysql.SelectPriv, dbName, t.Name.L, "", nil)
 	}
 
+	oldSchemaLen := p.Schema().Len()
 	if update.Where != nil {
 		p, err = b.buildSelection(ctx, p, update.Where, nil)
 		if err != nil {
 			return nil, err
 		}
 	}
+	// TODO: expression rewriter should not change the output columns. We should cut the columns here.
+	if p.Schema().Len() != oldSchemaLen {
+		proj := LogicalProjection{Exprs: expression.Column2Exprs(p.Schema().Columns[:oldSchemaLen])}.Init(b.ctx, b.getSelectOffset())
+		proj.SetSchema(expression.NewSchema(make([]*expression.Column, oldSchemaLen)...))
+		copy(proj.schema.Columns, p.Schema().Columns[:oldSchemaLen])
+		proj.SetChildren(p)
+		p = proj
+	}
 	if update.Order != nil {
 		p, err = b.buildSort(ctx, p, update.Order.Items, nil, nil)
 		if err != nil {

diff --git a/planner/core/logical_plan_test.go b/planner/core/logical_plan_test.go
@@ -970,6 +970,10 @@ func (s *testPlanSuite) TestPlanBuilder(c *C) {
 			// binlog columns, because the schema and data are not consistent.
 			plan: "LeftHashJoin{LeftHashJoin{TableReader(Table(t))->IndexLookUp(Index(t.c_d_e)[[666,666]], Table(t))}(Column#1,Column#14)->IndexReader(Index(t.c_d_e)[[42,42]])}(Column#2,Column#27)->Sel([or(Column#26, Column#40)])->Projection->Delete",
 		},
+		{
+			sql:  "update t set a = 2 where b in (select c from t)",
+			plan: "LeftHashJoin{TableReader(Table(t))->IndexReader(Index(t.c_d_e)[[NULL,+inf]])->HashAgg}(Column#2,Column#25)->Projection->Update",
+		},
 	}
 
 	ctx := context.Background()