Merge pull request #3110 from dolthub/angela/multidb

Use child column id's for union when assigning exec indexes

Author: angelamayxie

enginetest/queries/query_plans.go

@@ -11112,6 +11112,40 @@ where
 			},
 		},
 	},
+
+	{
+		// TODO: This test currently fails in Doltgres because Doltgres does not allow `create table...as select...`
+		// even though it's a valid Postgres query. Remove Dialect tag once fixed in Doltgres
+		// https://github.com/dolthub/doltgresql/issues/1669
+		Dialect: "mysql",
+		Name:    "union field indexes",
+		SetUpScript: []string{
+			"create table t(id int primary key auto_increment, words varchar(100))",
+			"insert into t(words) values ('foo'),('bar'),('baz'),('zap')",
+			"create table t2 as select * from t",
+			"update t2 set words = 'boo' where id = 1",
+		},
+		Assertions: []ScriptTestAssertion{
+			{
+				Query: "select * from " +
+					"(select id, words from t union " +
+					"select id,words from t2) as combined where combined.id=1",
+				Expected: []sql.Row{
+					{1, "foo"},
+					{1, "boo"},
+				},
+			},
+			{
+				Query: "select * from " +
+					"(select 'parent' as tbl, id, words from t union " +
+					"select 'child' as tbl, id,words from t2) as combined where combined.id=1",
+				Expected: []sql.Row{
+					{"parent", 1, "foo"},
+					{"child", 1, "boo"},
+				},
+			},
+		},
+	},
 }
 
 var SpatialScriptTests = []ScriptTest{

enginetest/queries/script_queries.go

@@ -692,6 +692,8 @@ func columnIdsForNode(n sql.Node) []sql.ColumnId {
 		default:
 			ret = append(ret, columnIdsForNode(n.Child)...)
 		}
+	case *plan.SetOp:
+		ret = append(ret, columnIdsForNode(n.Left())...)
 	case plan.TableIdNode:
 		if rt, ok := n.(*plan.ResolvedTable); ok && plan.IsDualTable(rt.Table) {
 			ret = append(ret, 0)
@@ -710,6 +712,8 @@ func columnIdsForNode(n sql.Node) []sql.ColumnId {
 				break
 			}
 		}
+		// TODO: columns are appended in increasing order by ColumnId instead of how they are actually ordered. likely
+		// needs to be fixed
 		cols.ForEach(func(col sql.ColumnId) {
 			ret = append(ret, col)
 		})

sql/analyzer/fix_exec_indexes.go

@@ -44,7 +44,8 @@ var _ sql.Node = (*SetOp)(nil)
 var _ sql.Expressioner = (*SetOp)(nil)
 var _ sql.CollationCoercible = (*SetOp)(nil)
 
-// var _ sql.NameableNode = (*SetOp)(nil)
+// TODO: This might not be necessary now that SetOp exec indexes are assigned based on its left child node, instead of
+// the cols in ColSet
 var _ TableIdNode = (*SetOp)(nil)
 
 // NewSetOp creates a new SetOp node with the given children.

sql/plan/set_op.go

@@ -90,7 +90,7 @@ func (b *Builder) buildRecursiveCte(inScope *scope, union *ast.SetOp, name strin
 		// not recursive
 		sqScope := inScope.pushSubquery()
 		cteScope := b.buildSelectStmt(sqScope, union)
-		b.renameSource(cteScope, name, columns)
+
 		switch n := cteScope.node.(type) {
 		case *plan.SetOp:
 			sq := plan.NewSubqueryAlias(name, "", n)
@@ -107,9 +107,9 @@ func (b *Builder) buildRecursiveCte(inScope *scope, union *ast.SetOp, name strin
 				colset.Add(sql.ColumnId(c.id))
 				scopeMapping[sql.ColumnId(c.id)] = c.scalarGf()
 			}
-
 			cteScope.node = sq.WithScopeMapping(scopeMapping).WithId(tabId).WithColumns(colset)
 		}
+		b.renameSource(cteScope, name, columns)
 		return cteScope
 	}