add foreign key constraints for bills and bill_owers tables

lib/Migration/Version010503Date20221030201200.php

@@ -0,0 +1,115 @@
+<?php
+
+namespace OCA\Cospend\Migration;
+
+use Closure;
+use Doctrine\DBAL\Schema\SchemaException;
+use OCP\DB\Exception;
+use OCP\DB\ISchemaWrapper;
+use OCP\DB\QueryBuilder\IQueryBuilder;
+use OCP\IDBConnection;
+use OCP\Migration\SimpleMigrationStep;
+use OCP\Migration\IOutput;
+
+class Version010503Date20221030201200 extends SimpleMigrationStep {
+	/**
+	 * @var IDBConnection
+	 */
+	private IDBConnection $connection;
+
+	/**
+	 * @param IDBConnection $connection
+	 */
+	public function __construct(IDBConnection $connection) {
+		$this->connection = $connection;
+	}
+
+	/**
+	 * @param IOutput $output
+	 * @param Closure $schemaClosure The `\Closure` returns a `ISchemaWrapper`
+	 * @param array $options
+	 * @throws Exception
+	 */
+	public function preSchemaChange(IOutput $output, Closure $schemaClosure, array $options) {
+		$queryBuilder = $this->connection->getQueryBuilder();
+
+		// get existing project ids
+		$queryBuilder->select('id')
+			->from('cospend_projects');
+		$result = $queryBuilder->executeQuery();
+
+		$existingProjectIds = [];
+		while ($row = $result->fetch()) {
+			$existingProjectIds[] = $queryBuilder->createNamedParameter($row['id'], IQueryBuilder::PARAM_STR);
+		}
+
+		$result->closeCursor();
+		$queryBuilder->resetQueryParts();
+
+		// delete bills without project
+		$queryBuilder->delete('cospend_bills')->where(
+			$queryBuilder->expr()->notIn('projectid', $existingProjectIds)
+		);
+		$queryBuilder->executeStatement();
+		$queryBuilder->resetQueryParts();
+
+		// get existing bill ids
+		$queryBuilder->select('id')
+			->from('cospend_bills');
+		$result = $queryBuilder->executeQuery();
+
+		$existingBillIds = [];
+		while ($row = $result->fetch()) {
+			$existingBillIds[] = $queryBuilder->createNamedParameter((int)$row['id'], IQueryBuilder::PARAM_INT);
+		}
+
+		$result->closeCursor();
+		$queryBuilder->resetQueryParts();
+
+		// delete bill owers without bill
+		$queryBuilder->delete('cospend_bill_owers')->where(
+			$queryBuilder->expr()->notIn('billid', $existingBillIds)
+		);
+		$queryBuilder->executeStatement();
+		$queryBuilder->resetQueryParts();
+	}
+
+	/**
+	 * @param IOutput $output
+	 * @param Closure $schemaClosure The `\Closure` returns a `ISchemaWrapper`
+	 * @param array $options
+	 * @return null|ISchemaWrapper
+	 * @throws SchemaException
+	 */
+	public function changeSchema(IOutput $output, Closure $schemaClosure, array $options): ?ISchemaWrapper {
+		/** @var ISchemaWrapper $schema */
+		$schema = $schemaClosure();
+
+		$schema->getTable('cospend_bills')
+			->addForeignKeyConstraint(
+				$schema->getTable('cospend_projects'),
+				['projectid'],
+				['id'],
+				['onDelete' => 'CASCADE', 'onUpdate' => 'CASCADE']
+			);
+
+		$schema->getTable('cospend_bill_owers')
+			->addForeignKeyConstraint(
+				$schema->getTable('cospend_bills'),
+				['billid'],
+				['id'],
+				['onDelete' => 'CASCADE', 'onUpdate' => 'CASCADE']
+			);
+
+
+		return $schema;
+	}
+
+	/**
+	 * @param IOutput $output
+	 * @param Closure $schemaClosure The `\Closure` returns a `ISchemaWrapper`
+	 * @param array $options
+	 */
+	public function postSchemaChange(IOutput $output, Closure $schemaClosure, array $options) {
+	}
+}