Merge pull request #28777 from nextcloud/backport/28677/stable22

[stable22] make it possible to override the default collation on mysql
nextcloud · Sep 10, 2021 · c57a621 · c57a621
2 parents c7159f9 + f353dd9
commit c57a621
Show file tree

Hide file tree

Showing 4 changed files with 31 additions and 9 deletions.
diff --git a/config/config.sample.php b/config/config.sample.php
@@ -1543,6 +1543,24 @@
  */
 'mysql.utf8mb4' => false,
 
+/**
+ * For search queries in the database, a default collation – depending on the
+ * character set – is chosen. In some cases a different behaviour is desired,
+ * for instances when a accent sensitive search is desired.
+ *
+ * MariaDB and MySQL have an overlap in available collations, but also
+ * incompatible ones, also depending on the version of the database server.
+ *
+ * This option allows to override the automatic choice. Example:
+ *
+ * 'mysql.collation' => 'utf8mb4_0900_as_ci',
+ *
+ * This setting has no effect on setup or creating tables. In those cases
+ * always utf8[mb4]_bin is being used. This setting is only taken into
+ * consideration in SQL queries that utilize LIKE comparison operators.
+ */
+'mysql.collation' => null,
+
 /**
  * Database types that are supported for installation.
  *

diff --git a/lib/private/DB/AdapterMySQL.php b/lib/private/DB/AdapterMySQL.php
@@ -25,7 +25,7 @@
 class AdapterMySQL extends Adapter {
 
 	/** @var string */
-	protected $charset;
+	protected $collation;
 
 	/**
 	 * @param string $tableName
@@ -39,16 +39,16 @@ public function unlockTable() {
 	}
 
 	public function fixupStatement($statement) {
-		$statement = str_replace(' ILIKE ', ' COLLATE ' . $this->getCharset() . '_general_ci LIKE ', $statement);
+		$statement = str_replace(' ILIKE ', ' COLLATE ' . $this->getCollation() . ' LIKE ', $statement);
 		return $statement;
 	}
 
-	protected function getCharset() {
-		if (!$this->charset) {
+	protected function getCollation(): string {
+		if (!$this->collation) {
 			$params = $this->conn->getParams();
-			$this->charset = isset($params['charset']) ? $params['charset'] : 'utf8';
+			$this->collation = $params['collation'] ?? (($params['charset'] ?? 'utf8') . '_general_ci');
 		}
 
-		return $this->charset;
+		return $this->collation;
 	}
 }
diff --git a/lib/private/DB/ConnectionFactory.php b/lib/private/DB/ConnectionFactory.php
@@ -89,6 +89,10 @@ public function __construct(SystemConfig $systemConfig) {
 		if ($this->config->getValue('mysql.utf8mb4', false)) {
 			$this->defaultConnectionParams['mysql']['charset'] = 'utf8mb4';
 		}
+		$collationOverride = $this->config->getValue('mysql.collation', null);
+		if ($collationOverride) {
+			$this->defaultConnectionParams['mysql']['collation'] = $collationOverride;
+		}
 	}
 
 	/**

diff --git a/lib/private/DB/QueryBuilder/ExpressionBuilder/MySqlExpressionBuilder.php b/lib/private/DB/QueryBuilder/ExpressionBuilder/MySqlExpressionBuilder.php
@@ -31,7 +31,7 @@
 class MySqlExpressionBuilder extends ExpressionBuilder {
 
 	/** @var string */
-	protected $charset;
+	protected $collation;
 
 	/**
 	 * @param ConnectionAdapter $connection
@@ -41,7 +41,7 @@ public function __construct(ConnectionAdapter $connection, IQueryBuilder $queryB
 		parent::__construct($connection, $queryBuilder);
 
 		$params = $connection->getInner()->getParams();
-		$this->charset = isset($params['charset']) ? $params['charset'] : 'utf8';
+		$this->collation = $params['collation'] ?? (($params['charset'] ?? 'utf8') . '_general_ci');
 	}
 
 	/**
@@ -50,6 +50,6 @@ public function __construct(ConnectionAdapter $connection, IQueryBuilder $queryB
 	public function iLike($x, $y, $type = null): string {
 		$x = $this->helper->quoteColumnName($x);
 		$y = $this->helper->quoteColumnName($y);
-		return $this->expressionBuilder->comparison($x, ' COLLATE ' . $this->charset . '_general_ci LIKE', $y);
+		return $this->expressionBuilder->comparison($x, ' COLLATE ' . $this->collation . ' LIKE', $y);
 	}
 }