diff --git a/README.md b/README.md index 001f25cc..4da9a0fd 100644 --- a/README.md +++ b/README.md @@ -147,6 +147,13 @@ db.AutoMigrate(&User{}, &Product{}, &Order{}) // Add index db.Model(&User{}).AddIndex("idx_user_name", "name") +// Add foreign key +// 1st param : foreignkey field +// 2nd param : destination table(id) +// 3rd param : ONDELETE +// 4th param : ONUPDATE +db.Model(&User{}).AddForeignKey("user_id", "destination_table(id)", "CASCADE", "RESTRICT") + // Multiple column index db.Model(&User{}).AddIndex("idx_user_name_age", "name", "age") diff --git a/main.go b/main.go index 9d833969..57c7d2a0 100644 --- a/main.go +++ b/main.go @@ -397,6 +397,17 @@ func (s *DB) AddIndex(indexName string, column ...string) *DB { return s } +/* +Add foreign key to the given scope + +Example: + db.Model(&User{}).AddForeignKey("city_id", "cities(id)", "RESTRICT", "RESTRICT") +*/ +func (s *DB) AddForeignKey(field string, dest string, onDelete string, onUpdate string) *DB { + s.clone().NewScope(s.Value).addForeignKey(field, dest, onDelete, onUpdate) + return s +} + func (s *DB) AddUniqueIndex(indexName string, column ...string) *DB { s.clone().NewScope(s.Value).addIndex(true, indexName, column...) return s diff --git a/scope_private.go b/scope_private.go index f481f378..1f173516 100644 --- a/scope_private.go +++ b/scope_private.go @@ -633,6 +633,20 @@ func (scope *Scope) addIndex(unique bool, indexName string, column ...string) { scope.Raw(fmt.Sprintf("%s %v ON %v(%v);", sqlCreate, indexName, scope.QuotedTableName(), strings.Join(columns, ", "))).Exec() } +func (scope *Scope) addForeignKey(field string, dest string, onDelete string, onUpdate string) { + var table string = scope.TableName() + var keyName string = fmt.Sprintf("%s_%s_foreign", table, field) + var query string = ` + ALTER TABLE %s + ADD CONSTRAINT %s + FOREIGN KEY (%s) + REFERENCES %s + ON DELETE %s + ON UPDATE %s; + ` + scope.Raw(fmt.Sprintf(query, table, keyName, field, dest, onDelete, onUpdate)).Exec() +} + func (scope *Scope) removeIndex(indexName string) { scope.Dialect().RemoveIndex(scope, indexName) }