fix cascade for foreign keys with multiple references (#2704)

Author: jycor

enginetest/queries/foreign_key_queries.go

@@ -2616,6 +2616,74 @@ var ForeignKeyTests = []ScriptTest{
 			},
 		},
 	},
+	{
+		Name: "multiple foreign key refs",
+		SetUpScript: []string{
+			"create table parent1 (i int primary key);",
+			"create table child1 (j int, k int, foreign key (j) references parent1(i) on delete cascade on update cascade, foreign key (k) references parent1 (i) on delete cascade on update cascade);",
+			"insert into parent1 values (1), (2), (3);",
+			"insert into child1 values (1, 2), (2, 3), (3, 1);",
+		},
+		Assertions: []ScriptTestAssertion{
+			{
+				Query: "select * from parent1;",
+				Expected: []sql.Row{
+					{1},
+					{2},
+					{3},
+				},
+			},
+			{
+				Query: "select * from child1 order by j, k;",
+				Expected: []sql.Row{
+					{1, 2},
+					{2, 3},
+					{3, 1},
+				},
+			},
+			{
+				Query: "update parent1 set i = 20 where i = 2;",
+				Expected: []sql.Row{
+					{types.OkResult{RowsAffected: 1, Info: plan.UpdateInfo{Matched: 1, Updated: 1}}},
+				},
+			},
+			{
+				Query: "select * from parent1 order by i;",
+				Expected: []sql.Row{
+					{1},
+					{3},
+					{20},
+				},
+			},
+			{
+				Query: "select * from child1 order by j, k;",
+				Expected: []sql.Row{
+					{1, 20},
+					{3, 1},
+					{20, 3},
+				},
+			},
+			{
+				Query: "delete from parent1 where i = 1;",
+				Expected: []sql.Row{
+					{types.OkResult{RowsAffected: 1}},
+				},
+			},
+			{
+				Query: "select * from parent1;",
+				Expected: []sql.Row{
+					{3},
+					{20},
+				},
+			},
+			{
+				Query: "select * from child1 order by j, k;",
+				Expected: []sql.Row{
+					{20, 3},
+				},
+			},
+		},
+	},
 }
 
 var CreateForeignKeyTests = []ScriptTest{

enginetest/queries/update_queries.go

@@ -707,9 +707,9 @@ var UpdateIgnoreScripts = []ScriptTest{
 		Name: "UPDATE IGNORE with foreign keys",
 		SetUpScript: []string{
 			"CREATE TABLE colors ( id INT NOT NULL, color VARCHAR(32) NOT NULL, PRIMARY KEY (id), INDEX color_index(color));",
-			"CREATE TABLE objects (id INT NOT NULL, name VARCHAR(64) NOT NULL,color VARCHAR(32), PRIMARY KEY(id),FOREIGN KEY (color) REFERENCES colors(color))",
-			"INSERT INTO colors (id,color) VALUES (1,'red'),(2,'green'),(3,'blue'),(4,'purple')",
-			"INSERT INTO objects (id,name,color) VALUES (1,'truck','red'),(2,'ball','green'),(3,'shoe','blue')",
+			"CREATE TABLE objects (id INT NOT NULL, name VARCHAR(64) NOT NULL,color VARCHAR(32), PRIMARY KEY(id),FOREIGN KEY (color) REFERENCES colors(color));",
+			"INSERT INTO colors (id,color) VALUES (1,'red'),(2,'green'),(3,'blue'),(4,'purple');",
+			"INSERT INTO objects (id,name,color) VALUES (1,'truck','red'),(2,'ball','green'),(3,'shoe','blue');",
 		},
 		Assertions: []ScriptTestAssertion{
 			{

sql/analyzer/apply_foreign_keys.go

@@ -40,9 +40,7 @@ func applyForeignKeys(ctx *sql.Context, a *Analyzer, n sql.Node, scope *plan.Sco
 // and caching of table editors.
 func applyForeignKeysToNodes(ctx *sql.Context, a *Analyzer, n sql.Node, cache *foreignKeyCache) (sql.Node, transform.TreeIdentity, error) {
 	var err error
-	fkChain := foreignKeyChain{
-		fkUpdate: make(map[foreignKeyTableName]sql.ForeignKeyEditor),
-	}
+	fkChain := newForeignKeyChain()
 
 	switch n := n.(type) {
 	case *plan.CreateTable:
@@ -209,7 +207,11 @@ func getForeignKeyEditor(ctx *sql.Context, a *Analyzer, tbl sql.ForeignKeyTable,
 	if err != nil {
 		return nil, err
 	}
-	return getForeignKeyRefActions(ctx, a, tbl, cache, fkChain, fkEditor, checkRows)
+	fkEditor, err = getForeignKeyRefActions(ctx, a, tbl, cache, fkChain, fkEditor, checkRows)
+	if err != nil {
+		return nil, err
+	}
+	return fkEditor, err
 }
 
 // getForeignKeyReferences returns an editor containing only the references for the given table.
@@ -238,7 +240,7 @@ func getForeignKeyReferences(ctx *sql.Context, a *Analyzer, tbl sql.ForeignKeyTa
 	if err != nil {
 		return nil, err
 	}
-	fkChain = fkChain.AddTable(fks[0].ParentDatabase, fks[0].ParentTable).AddTableUpdater(fks[0].ParentDatabase, fks[0].ParentTable, updater)
+	fkChain = fkChain.AddTable(fks[0].Database, fks[0].Table).AddTableUpdater(fks[0].Database, fks[0].Table, updater)
 
 	tblSch := tbl.Schema()
 	fkEditor := &plan.ForeignKeyEditor{
@@ -426,6 +428,13 @@ type foreignKeyTableName struct {
 	tblName string
 }
 
+func newForeignKeyTableName(dbName, tblName string) foreignKeyTableName {
+	return foreignKeyTableName{
+		dbName:  strings.ToLower(dbName),
+		tblName: strings.ToLower(tblName),
+	}
+}
+
 // foreignKeyTableUpdater is a foreign key table along with its updater.
 type foreignKeyTableUpdater struct {
 	tbl     sql.ForeignKeyTable
@@ -539,9 +548,17 @@ func (cache *foreignKeyCache) GetEditor(fkEditor *plan.ForeignKeyEditor, dbName
 // updaters that are not a part of this chain. In addition, any updaters that cannot be modified (such as those
 // belonging to strictly RESTRICT referential actions) will not appear in the chain.
 type foreignKeyChain struct {
-	fkNames  map[string]struct{}
-	fkTables map[foreignKeyTableName]struct{}
-	fkUpdate map[foreignKeyTableName]sql.ForeignKeyEditor
+	fkNames    map[string]struct{}
+	fkTables   map[foreignKeyTableName]struct{}
+	fkUpdaters map[foreignKeyTableName]sql.ForeignKeyEditor
+}
+
+func newForeignKeyChain() foreignKeyChain {
+	return foreignKeyChain{
+		fkNames:    make(map[string]struct{}),
+		fkTables:   make(map[foreignKeyTableName]struct{}),
+		fkUpdaters: make(map[foreignKeyTableName]sql.ForeignKeyEditor),
+	}
 }
 
 // AddTable returns a new chain with the added table.
@@ -554,23 +571,17 @@ func (chain foreignKeyChain) AddTable(dbName string, tblName string) foreignKeyC
 	for fkTable := range chain.fkTables {
 		newFkTables[fkTable] = struct{}{}
 	}
-	newFkTables[foreignKeyTableName{
-		dbName:  strings.ToLower(dbName),
-		tblName: strings.ToLower(tblName),
-	}] = struct{}{}
+	newFkTables[newForeignKeyTableName(dbName, tblName)] = struct{}{}
 	return foreignKeyChain{
-		fkNames:  newFkNames,
-		fkTables: newFkTables,
-		fkUpdate: chain.fkUpdate,
+		fkNames:    newFkNames,
+		fkTables:   newFkTables,
+		fkUpdaters: chain.fkUpdaters,
 	}
 }
 
 // AddTableUpdater returns a new chain with the added foreign key updater.
 func (chain foreignKeyChain) AddTableUpdater(dbName string, tblName string, fkUpdater sql.ForeignKeyEditor) foreignKeyChain {
-	chain.fkUpdate[foreignKeyTableName{
-		dbName:  strings.ToLower(dbName),
-		tblName: strings.ToLower(tblName),
-	}] = fkUpdater
+	chain.fkUpdaters[newForeignKeyTableName(dbName, tblName)] = fkUpdater
 	return chain
 }
 
@@ -586,35 +597,28 @@ func (chain foreignKeyChain) AddForeignKey(fkName string) foreignKeyChain {
 	}
 	newFkNames[strings.ToLower(fkName)] = struct{}{}
 	return foreignKeyChain{
-		fkNames:  newFkNames,
-		fkTables: newFkTables,
-		fkUpdate: chain.fkUpdate,
+		fkNames:    newFkNames,
+		fkTables:   newFkTables,
+		fkUpdaters: chain.fkUpdaters,
 	}
 }
 
 // HasTable returns whether the chain contains the given table. Case-insensitive.
 func (chain foreignKeyChain) HasTable(dbName string, tblName string) bool {
-	if _, ok := chain.fkTables[foreignKeyTableName{
-		dbName:  strings.ToLower(dbName),
-		tblName: strings.ToLower(tblName),
-	}]; ok {
-		return true
-	}
-	return false
+	_, ok := chain.fkTables[newForeignKeyTableName(dbName, tblName)]
+	return ok
 }
 
 // HasForeignKey returns whether the chain contains the given foreign key. Case-insensitive.
 func (chain foreignKeyChain) HasForeignKey(fkName string) bool {
-	if _, ok := chain.fkNames[strings.ToLower(fkName)]; ok {
-		return true
-	}
-	return false
+	_, ok := chain.fkNames[strings.ToLower(fkName)]
+	return ok
 }
 
 // GetUpdaters returns all foreign key updaters that have been added to the chain.
 func (chain foreignKeyChain) GetUpdaters() []sql.ForeignKeyEditor {
-	updaters := make([]sql.ForeignKeyEditor, 0, len(chain.fkUpdate))
-	for _, updater := range chain.fkUpdate {
+	updaters := make([]sql.ForeignKeyEditor, 0, len(chain.fkUpdaters))
+	for _, updater := range chain.fkUpdaters {
 		updaters = append(updaters, updater)
 	}
 	return updaters