Merge pull request #30393 from nextcloud/feature/add-group-concat-aggregator-function

Add group_concat aggregator function

lib/private/DB/QueryBuilder/FunctionBuilder/FunctionBuilder.php

@@ -26,18 +26,23 @@ namespace OC\DB\QueryBuilder\FunctionBuilder;
 use OC\DB\QueryBuilder\QueryFunction;
 use OC\DB\QueryBuilder\QuoteHelper;
 use OCP\DB\QueryBuilder\IFunctionBuilder;
+use OCP\DB\QueryBuilder\IQueryBuilder;
 use OCP\DB\QueryBuilder\IQueryFunction;
+use OCP\IDBConnection;
 
 class FunctionBuilder implements IFunctionBuilder {
+	/** @var IDBConnection */
+	protected $connection;
+
+	/** @var IQueryBuilder */
+	protected $queryBuilder;
+
 	/** @var QuoteHelper */
 	protected $helper;
 
-	/**
-	 * ExpressionBuilder constructor.
-	 *
-	 * @param QuoteHelper $helper
-	 */
-	public function __construct(QuoteHelper $helper) {
+	public function __construct(IDBConnection $connection, IQueryBuilder $queryBuilder, QuoteHelper $helper) {
+		$this->connection = $connection;
+		$this->queryBuilder = $queryBuilder;
 		$this->helper = $helper;
 	}
 
@@ -49,6 +54,11 @@ class FunctionBuilder implements IFunctionBuilder {
 		return new QueryFunction('CONCAT(' . $this->helper->quoteColumnName($x) . ', ' . $this->helper->quoteColumnName($y) . ')');
 	}
 
+	public function groupConcat($expr, ?string $separator = ','): IQueryFunction {
+		$separator = $this->connection->quote($separator);
+		return new QueryFunction('GROUP_CONCAT(' . $this->helper->quoteColumnName($expr) . ' SEPARATOR ' . $separator . ')');
+	}
+
 	public function substring($input, $start, $length = null): IQueryFunction {
 		if ($length) {
 			return new QueryFunction('SUBSTR(' . $this->helper->quoteColumnName($input) . ', ' . $this->helper->quoteColumnName($start) . ', ' . $this->helper->quoteColumnName($length) . ')');

lib/private/DB/QueryBuilder/FunctionBuilder/OCIFunctionBuilder.php

@@ -72,4 +72,14 @@ class OCIFunctionBuilder extends FunctionBuilder {
 
 		return parent::least($x, $y);
 	}
+
+	public function groupConcat($expr, ?string $separator = ','): IQueryFunction {
+		$orderByClause = ' WITHIN GROUP(ORDER BY NULL)';
+		if (is_null($separator)) {
+			return new QueryFunction('LISTAGG(' . $this->helper->quoteColumnName($expr) . ')' . $orderByClause);
+		}
+
+		$separator = $this->connection->quote($separator);
+		return new QueryFunction('LISTAGG(' . $this->helper->quoteColumnName($expr) . ', ' . $separator . ')' . $orderByClause);
+	}
 }

lib/private/DB/QueryBuilder/FunctionBuilder/PgSqlFunctionBuilder.php

@@ -24,10 +24,22 @@
 namespace OC\DB\QueryBuilder\FunctionBuilder;
 
 use OC\DB\QueryBuilder\QueryFunction;
+use OCP\DB\QueryBuilder\IQueryBuilder;
 use OCP\DB\QueryBuilder\IQueryFunction;
 
 class PgSqlFunctionBuilder extends FunctionBuilder {
 	public function concat($x, $y): IQueryFunction {
 		return new QueryFunction('(' . $this->helper->quoteColumnName($x) . ' || ' . $this->helper->quoteColumnName($y) . ')');
 	}
+
+	public function groupConcat($expr, ?string $separator = ','): IQueryFunction {
+		$castedExpression = $this->queryBuilder->expr()->castColumn($expr, IQueryBuilder::PARAM_STR);
+
+		if (is_null($separator)) {
+			return new QueryFunction('string_agg(' . $castedExpression . ')');
+		}
+
+		$separator = $this->connection->quote($separator);
+		return new QueryFunction('string_agg(' . $castedExpression . ', ' . $separator . ')');
+	}
 }

lib/private/DB/QueryBuilder/FunctionBuilder/SqliteFunctionBuilder.php

@@ -31,6 +31,11 @@ class SqliteFunctionBuilder extends FunctionBuilder {
 		return new QueryFunction('(' . $this->helper->quoteColumnName($x) . ' || ' . $this->helper->quoteColumnName($y) . ')');
 	}
 
+	public function groupConcat($expr, ?string $separator = ','): IQueryFunction {
+		$separator = $this->connection->quote($separator);
+		return new QueryFunction('GROUP_CONCAT(' . $this->helper->quoteColumnName($expr) . ', ' . $separator . ')');
+	}
+
 	public function greatest($x, $y): IQueryFunction {
 		return new QueryFunction('MAX(' . $this->helper->quoteColumnName($x) . ', ' . $this->helper->quoteColumnName($y) . ')');
 	}

lib/private/DB/QueryBuilder/QueryBuilder.php

@@ -155,16 +155,16 @@ class QueryBuilder implements IQueryBuilder {
 	 */
 	public function func() {
 		if ($this->connection->getDatabasePlatform() instanceof OraclePlatform) {
-			return new OCIFunctionBuilder($this->helper);
+			return new OCIFunctionBuilder($this->connection, $this, $this->helper);
 		}
 		if ($this->connection->getDatabasePlatform() instanceof SqlitePlatform) {
-			return new SqliteFunctionBuilder($this->helper);
+			return new SqliteFunctionBuilder($this->connection, $this, $this->helper);
 		}
 		if ($this->connection->getDatabasePlatform() instanceof PostgreSQL94Platform) {
-			return new PgSqlFunctionBuilder($this->helper);
+			return new PgSqlFunctionBuilder($this->connection, $this, $this->helper);
 		}
 
-		return new FunctionBuilder($this->helper);
+		return new FunctionBuilder($this->connection, $this, $this->helper);
 	}
 
 	/**

lib/public/DB/QueryBuilder/IFunctionBuilder.php

@@ -44,13 +44,29 @@ interface IFunctionBuilder {
 	 * Combines two input strings
 	 *
 	 * @param string|ILiteral|IParameter|IQueryFunction $x The first input string
-	 * @param string|ILiteral|IParameter|IQueryFunction $y The seccond input string
+	 * @param string|ILiteral|IParameter|IQueryFunction $y The second input string
 	 *
 	 * @return IQueryFunction
 	 * @since 12.0.0
 	 */
 	public function concat($x, $y): IQueryFunction;
 
+	/**
+	 * Returns a string which is the concatenation of all non-NULL values of X
+	 *
+	 * Usage examples:
+	 *
+	 * groupConcat('column') -- with comma as separator (default separator)
+	 *
+	 * groupConcat('column', ';') -- with different separator
+	 *
+	 * @param string|IQueryFunction $expr The expression to group
+	 * @param string|null $separator The separator
+	 * @return IQueryFunction
+	 * @since 24.0.0
+	 */
+	public function groupConcat($expr, ?string $separator = ','): IQueryFunction;
+
 	/**
 	 * Takes a substring from the input string
 	 *

tests/lib/DB/QueryBuilder/FunctionBuilderTest.php

@@ -54,6 +54,149 @@ class FunctionBuilderTest extends TestCase {
 		$this->assertEquals('foobar', $column);
 	}
 
+	protected function clearDummyData(): void {
+		$delete = $this->connection->getQueryBuilder();
+
+		$delete->delete('appconfig')
+			->where($delete->expr()->eq('appid', $delete->createNamedParameter('group_concat')));
+		$delete->executeStatement();
+	}
+
+	protected function addDummyData(): void {
+		$this->clearDummyData();
+		$insert = $this->connection->getQueryBuilder();
+
+		$insert->insert('appconfig')
+			->setValue('appid', $insert->createNamedParameter('group_concat'))
+			->setValue('configvalue', $insert->createNamedParameter('unittest'))
+			->setValue('configkey', $insert->createParameter('value'));
+
+		$insert->setParameter('value', '1');
+		$insert->executeStatement();
+		$insert->setParameter('value', '3');
+		$insert->executeStatement();
+		$insert->setParameter('value', '2');
+		$insert->executeStatement();
+	}
+
+	public function testGroupConcatWithoutSeparator(): void {
+		$this->addDummyData();
+		$query = $this->connection->getQueryBuilder();
+
+		$query->select($query->func()->groupConcat('configkey'))
+			->from('appconfig')
+			->where($query->expr()->eq('appid', $query->createNamedParameter('group_concat')));
+
+		$result = $query->execute();
+		$column = $result->fetchOne();
+		$result->closeCursor();
+		$this->assertEquals('1,2,3', $column);
+		$this->assertStringContainsString(',', $column);
+		$actual = explode(',', $column);
+		$this->assertEqualsCanonicalizing([1,2,3], $actual);
+	}
+
+	public function testGroupConcatWithSeparator(): void {
+		$this->addDummyData();
+		$query = $this->connection->getQueryBuilder();
+
+		$query->select($query->func()->groupConcat('configkey', '#'))
+			->from('appconfig')
+			->where($query->expr()->eq('appid', $query->createNamedParameter('group_concat')));
+
+		$result = $query->execute();
+		$column = $result->fetchOne();
+		$result->closeCursor();
+		$this->assertStringContainsString('#', $column);
+		$actual = explode('#', $column);
+		$this->assertEqualsCanonicalizing([1,2,3], $actual);
+	}
+
+	public function testGroupConcatWithSingleQuoteSeparator(): void {
+		$this->addDummyData();
+		$query = $this->connection->getQueryBuilder();
+
+		$query->select($query->func()->groupConcat('configkey', '\''))
+			->from('appconfig')
+			->where($query->expr()->eq('appid', $query->createNamedParameter('group_concat')));
+
+		$result = $query->execute();
+		$column = $result->fetchOne();
+		$result->closeCursor();
+		$this->assertEquals('1\'2\'3', $column);
+	}
+
+	public function testGroupConcatWithDoubleQuoteSeparator(): void {
+		$this->addDummyData();
+		$query = $this->connection->getQueryBuilder();
+
+		$query->select($query->func()->groupConcat('configkey', '"'))
+			->from('appconfig')
+			->where($query->expr()->eq('appid', $query->createNamedParameter('group_concat')));
+
+		$result = $query->execute();
+		$column = $result->fetchOne();
+		$result->closeCursor();
+		$this->assertEquals('1"2"3', $column);
+	}
+
+	protected function clearIntDummyData(): void {
+		$delete = $this->connection->getQueryBuilder();
+
+		$delete->delete('systemtag')
+			->where($delete->expr()->eq('name', $delete->createNamedParameter('group_concat')));
+		$delete->executeStatement();
+	}
+
+	protected function addIntDummyData(): void {
+		$this->clearIntDummyData();
+		$insert = $this->connection->getQueryBuilder();
+
+		$insert->insert('systemtag')
+			->setValue('name', $insert->createNamedParameter('group_concat'))
+			->setValue('visibility', $insert->createNamedParameter(1))
+			->setValue('editable', $insert->createParameter('value'));
+
+		$insert->setParameter('value', 1);
+		$insert->executeStatement();
+		$insert->setParameter('value', 2);
+		$insert->executeStatement();
+		$insert->setParameter('value', 3);
+		$insert->executeStatement();
+	}
+
+	public function testIntGroupConcatWithoutSeparator(): void {
+		$this->addIntDummyData();
+		$query = $this->connection->getQueryBuilder();
+
+		$query->select($query->func()->groupConcat('editable'))
+			->from('systemtag')
+			->where($query->expr()->eq('name', $query->createNamedParameter('group_concat')));
+
+		$result = $query->execute();
+		$column = $result->fetchOne();
+		$result->closeCursor();
+		$this->assertStringContainsString(',', $column);
+		$actual = explode(',', $column);
+		$this->assertEqualsCanonicalizing([1,2,3], $actual);
+	}
+
+	public function testIntGroupConcatWithSeparator(): void {
+		$this->addIntDummyData();
+		$query = $this->connection->getQueryBuilder();
+
+		$query->select($query->func()->groupConcat('editable', '#'))
+			->from('systemtag')
+			->where($query->expr()->eq('name', $query->createNamedParameter('group_concat')));
+
+		$result = $query->execute();
+		$column = $result->fetchOne();
+		$result->closeCursor();
+		$this->assertStringContainsString('#', $column);
+		$actual = explode('#', $column);
+		$this->assertEqualsCanonicalizing([1,2,3], $actual);
+	}
+
 	public function testMd5() {
 		$query = $this->connection->getQueryBuilder();