Auto-generate foreign key constraint names when not provided

src/Db/Adapter/MysqlAdapter.php

@@ -977,7 +977,7 @@ protected function getAddForeignKeyInstructions(TableMetadata $table, ForeignKey
     {
         $alter = sprintf(
             'ADD %s',
-            $this->getForeignKeySqlDefinition($foreignKey),
+            $this->getForeignKeySqlDefinition($foreignKey, $table->getName()),
         );
 
         return new AlterInstructions([$alter]);
@@ -1192,14 +1192,13 @@ protected function getIndexSqlDefinition(Index $index): string
      * Gets the MySQL Foreign Key Definition for an ForeignKey object.
      *
      * @param \Migrations\Db\Table\ForeignKey $foreignKey Foreign key
+     * @param string $tableName Table name for auto-generating constraint name
      * @return string
      */
-    protected function getForeignKeySqlDefinition(ForeignKey $foreignKey): string
+    protected function getForeignKeySqlDefinition(ForeignKey $foreignKey, string $tableName): string
     {
-        $def = '';
-        if ($foreignKey->getName()) {
-            $def .= ' CONSTRAINT ' . $this->quoteColumnName((string)$foreignKey->getName());
-        }
+        $constraintName = $foreignKey->getName() ?: ($tableName . '_' . implode('_', $foreignKey->getColumns()));
+        $def = ' CONSTRAINT ' . $this->quoteColumnName($constraintName);
         $columnNames = [];
         foreach ($foreignKey->getColumns() as $column) {
             $columnNames[] = $this->quoteColumnName($column);

src/Db/Adapter/SqliteAdapter.php

@@ -1425,7 +1425,7 @@ protected function getAddForeignKeyInstructions(TableMetadata $table, ForeignKey
         $tableName = $table->getName();
         $instructions->addPostStep(function ($state) use ($foreignKey, $tableName) {
             $this->execute('pragma foreign_keys = ON');
-            $sql = substr($state['createSQL'], 0, -1) . ',' . $this->getForeignKeySqlDefinition($foreignKey) . '); ';
+            $sql = substr($state['createSQL'], 0, -1) . ',' . $this->getForeignKeySqlDefinition($foreignKey, $tableName) . '); ';
 
             //Delete indexes from original table and recreate them in temporary table
             $schema = $this->getSchemaName($tableName, true)['schema'];
@@ -1670,14 +1670,13 @@ public function getColumnTypes(): array
      * Gets the SQLite Foreign Key Definition for an ForeignKey object.
      *
      * @param \Migrations\Db\Table\ForeignKey $foreignKey Foreign key
+     * @param string $tableName Table name for auto-generating constraint name
      * @return string
      */
-    protected function getForeignKeySqlDefinition(ForeignKey $foreignKey): string
+    protected function getForeignKeySqlDefinition(ForeignKey $foreignKey, string $tableName): string
     {
-        $def = '';
-        if ($foreignKey->getName()) {
-            $def .= ' CONSTRAINT ' . $this->quoteColumnName((string)$foreignKey->getName());
-        }
+        $constraintName = $foreignKey->getName() ?: ($tableName . '_' . implode('_', $foreignKey->getColumns()));
+        $def = ' CONSTRAINT ' . $this->quoteColumnName($constraintName);
         $columnNames = [];
         foreach ($foreignKey->getColumns() as $column) {
             $columnNames[] = $this->quoteColumnName($column);

tests/comparisons/Diff/default/the_diff_default_mysql.php

@@ -16,7 +16,7 @@ class TheDiffDefaultMysql extends BaseMigration
     public function up(): void
     {
         $this->table('articles')
-            ->dropForeignKey([], 'articles_ibfk_1')
+            ->dropForeignKey([], 'articles_user_id')
             ->removeIndexByName('UNIQUE_SLUG')
             ->removeIndexByName('rating_index')
             ->removeIndexByName('BY_NAME')
@@ -86,7 +86,7 @@ public function up(): void
             ])
             ->addIndex(
                 $this->index('user_id')
-                    ->setName('categories_ibfk_1')
+                    ->setName('categories_user_id')
             )
             ->addIndex(
                 $this->index('name')
@@ -101,7 +101,7 @@ public function up(): void
                     ->setReferencedColumns('id')
                     ->setOnDelete('RESTRICT')
                     ->setOnUpdate('RESTRICT')
-                    ->setName('categories_ibfk_1')
+                    ->setName('categories_user_id')
             )
             ->update();
 
@@ -234,7 +234,7 @@ public function down(): void
                     ->setReferencedColumns('id')
                     ->setOnDelete('CASCADE')
                     ->setOnUpdate('CASCADE')
-                    ->setName('articles_ibfk_1')
+                    ->setName('articles_user_id')
             )
             ->update();
 

tests/comparisons/Diff/simple/the_diff_simple_mysql.php

@@ -72,7 +72,7 @@ public function up(): void
                     ->setReferencedColumns('id')
                     ->setOnDelete('RESTRICT')
                     ->setOnUpdate('RESTRICT')
-                    ->setName('articles_ibfk_1')
+                    ->setName('articles_user_id')
             )
             ->update();
     }