Symfony Doctrine Models for Entity Without Primary Keys - symfony1

Question

I'm working with a legacy database while re-building the web application. I want to use Symfony2.x which obviously has Doctrine as ORM.
I've around 50 (mysql) tables which has NO Primary Keys. When I try to generate models, it does not let me do and throw an exception with "No Primary Key on ... table".
Do I must have Primary Keys on tables to use Doctrine or is there any way around it?
Any help would be great.
Thanks.

Answer 1

Doctrine requires every entity class to have an identifier/primary key.
Take a look at this page: http://www.doctrine-project.org/docs/orm/2.0/en/reference/basic-mapping.html#identifiers-primary-keys

Answer 2

It is a requirement for Doctrine to have an identifier/primary key.
Take a look at this page: http://www.doctrine-project.org/docs/orm/2.0/en/reference/basic-mapping.html#identifiers-primary-keys
But there is a way to generate mappings and entities from tables that do not have a primary key. A table with no primary key is an unusual and bad database design but such a scenario exists in case of legacy databases.
Solution:
Note: All references below refer to Doctrine 2.0
1. Find the file DatabaseDriver.php (in Doctrine/ORM/Mapping/Driver/DatabaseDriver.php)
2. Find the method reverseEngineerMappingFromDatabase. Modify the code as stated below. The original code is:
private function reverseEngineerMappingFromDatabase()
{
if ($this->tables !== null) {
return;
}
$tables = array();
foreach ($this->_sm->listTableNames() as $tableName) {
$tables[$tableName] = $this->_sm->listTableDetails($tableName);
}
$this->tables = $this->manyToManyTables = $this->classToTableNames = array();
foreach ($tables as $tableName => $table) {
/* #var $table \Doctrine\DBAL\Schema\Table */
if ($this->_sm->getDatabasePlatform()->supportsForeignKeyConstraints()) {
$foreignKeys = $table->getForeignKeys();
} else {
$foreignKeys = array();
}
$allForeignKeyColumns = array();
foreach ($foreignKeys as $foreignKey) {
$allForeignKeyColumns = array_merge($allForeignKeyColumns, $foreignKey->getLocalColumns());
}
if ( ! $table->hasPrimaryKey()) {
throw new MappingException(
"Table " . $table->getName() . " has no primary key. Doctrine does not ".
"support reverse engineering from tables that don't have a primary key."
);
}
$pkColumns = $table->getPrimaryKey()->getColumns();
sort($pkColumns);
sort($allForeignKeyColumns);
if ($pkColumns == $allForeignKeyColumns && count($foreignKeys) == 2) {
$this->manyToManyTables[$tableName] = $table;
} else {
// lower-casing is necessary because of Oracle Uppercase Tablenames,
// assumption is lower-case + underscore separated.
$className = $this->getClassNameForTable($tableName);
$this->tables[$tableName] = $table;
$this->classToTableNames[$className] = $tableName;
}
}
}
The modified code is:
private function reverseEngineerMappingFromDatabase()
{
if ($this->tables !== null) {
return;
}
$tables = array();
foreach ($this->_sm->listTableNames() as $tableName) {
$tables[$tableName] = $this->_sm->listTableDetails($tableName);
}
$this->tables = $this->manyToManyTables = $this->classToTableNames = array();
foreach ($tables as $tableName => $table) {
/* #var $table \Doctrine\DBAL\Schema\Table */
if ($this->_sm->getDatabasePlatform()->supportsForeignKeyConstraints()) {
$foreignKeys = $table->getForeignKeys();
} else {
$foreignKeys = array();
}
$allForeignKeyColumns = array();
foreach ($foreignKeys as $foreignKey) {
$allForeignKeyColumns = array_merge($allForeignKeyColumns, $foreignKey->getLocalColumns());
}
$pkColumns=array();
if ($table->hasPrimaryKey()) {
$pkColumns = $table->getPrimaryKey()->getColumns();
sort($pkColumns);
}
sort($allForeignKeyColumns);
if ($pkColumns == $allForeignKeyColumns && count($foreignKeys) == 2) {
$this->manyToManyTables[$tableName] = $table;
} else {
// lower-casing is necessary because of Oracle Uppercase Tablenames,
// assumption is lower-case + underscore separated.
$className = $this->getClassNameForTable($tableName);
$this->tables[$tableName] = $table;
$this->classToTableNames[$className] = $tableName;
}
}
}
3. Find the method loadMetadataForClass in the same file. Modify the code as stated below.
Find the code stated below:
try {
$primaryKeyColumns = $this->tables[$tableName]->getPrimaryKey()->getColumns();
} catch(SchemaException $e) {
$primaryKeyColumns = array();
}
Modify it like this:
try {
$primaryKeyColumns = ($this->tables[$tableName]->hasPrimaryKey())?$this->tables[$tableName]->getPrimaryKey()->getColumns():array();
} catch(SchemaException $e) {
$primaryKeyColumns = array();
}
The above solution creates mappings(xml/yml/annotation) even for tables that don't have a primary key.