1 files changed, 33 insertions, 0 deletions
diff --git a/lib/private/DB/QueryBuilder/FunctionBuilder/PgSqlFunctionBuilder.php b/lib/private/DB/QueryBuilder/FunctionBuilder/PgSqlFunctionBuilder.php
new file mode 100644
index 00000000000..354a2b126d7
--- /dev/null
+++ b/lib/private/DB/QueryBuilder/FunctionBuilder/PgSqlFunctionBuilder.php
@@ -0,0 +1,33 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2017 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+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($x, ...$expr): IQueryFunction {
+		$args = func_get_args();
+		$list = [];
+		foreach ($args as $item) {
+			$list[] = $this->queryBuilder->expr()->castColumn($item, IQueryBuilder::PARAM_STR);
+		}
+		return new QueryFunction(sprintf('(%s)', implode(' || ', $list)));
+	}
+
+	public function groupConcat($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 . ')');
+	}
+}