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

Add group_concat aggregator function

6 files changed, 64 insertions, 11 deletions

diff --git a/lib/private/DB/QueryBuilder/FunctionBuilder/FunctionBuilder.php b/lib/private/DB/QueryBuilder/FunctionBuilder/FunctionBuilder.php
index dfc0d0a6d61..37518bda3ec 100644
--- a/lib/private/DB/QueryBuilder/FunctionBuilder/FunctionBuilder.php
+++ b/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) . ')');
diff --git a/lib/private/DB/QueryBuilder/FunctionBuilder/OCIFunctionBuilder.php b/lib/private/DB/QueryBuilder/FunctionBuilder/OCIFunctionBuilder.php
index 5581207a166..3871070a583 100644
--- a/lib/private/DB/QueryBuilder/FunctionBuilder/OCIFunctionBuilder.php
+++ b/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);
+	}
 }
diff --git a/lib/private/DB/QueryBuilder/FunctionBuilder/PgSqlFunctionBuilder.php b/lib/private/DB/QueryBuilder/FunctionBuilder/PgSqlFunctionBuilder.php
index 853c65ac32a..0b22775acc8 100644
--- a/lib/private/DB/QueryBuilder/FunctionBuilder/PgSqlFunctionBuilder.php
+++ b/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 . ')');
+	}
 }
diff --git a/lib/private/DB/QueryBuilder/FunctionBuilder/SqliteFunctionBuilder.php b/lib/private/DB/QueryBuilder/FunctionBuilder/SqliteFunctionBuilder.php
index 19cff52546b..1067f8f0925 100644
--- a/lib/private/DB/QueryBuilder/FunctionBuilder/SqliteFunctionBuilder.php
+++ b/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) . ')');
 	}
diff --git a/lib/private/DB/QueryBuilder/QueryBuilder.php b/lib/private/DB/QueryBuilder/QueryBuilder.php
index 89265c74fae..a362ff8016e 100644
--- a/lib/private/DB/QueryBuilder/QueryBuilder.php
+++ b/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);
 	}
 
 	/**
diff --git a/lib/public/DB/QueryBuilder/IFunctionBuilder.php b/lib/public/DB/QueryBuilder/IFunctionBuilder.php
index 33d0fbe3b1a..1e8d8c89f81 100644
--- a/lib/public/DB/QueryBuilder/IFunctionBuilder.php
+++ b/lib/public/DB/QueryBuilder/IFunctionBuilder.php
@@ -44,7 +44,7 @@ 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 $y The second input string
 	 *
 	 * @return IQueryFunction
 	 * @since 12.0.0
@@ -52,6 +52,22 @@ interface IFunctionBuilder {
 	public function concat($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
 	 *
 	 * @param string|ILiteral|IParameter|IQueryFunction $input The input string