rdbms: add limitResults() to IDatabase

[lhc/web/wiklou.git] / includes / libs / rdbms / database / IDatabase.php

diff --git a/includes/libs/rdbms/database/IDatabase.php b/includes/libs/rdbms/database/IDatabase.php
index 90b888d..592c9be 100644 (file)
--- a/includes/libs/rdbms/database/IDatabase.php
+++ b/includes/libs/rdbms/database/IDatabase.php
@@ -113,6 +113,8 @@ interface IDatabase {
         *   permanent as far as write tracking is concerned. This is useful for testing.
         */
        const QUERY_PSEUDO_PERMANENT = 2;
+       /** @var int Enforce that a query does not make effective writes */
+       const QUERY_REPLICA_ROLE = 4;
 
        /** @var bool Parameter to unionQueries() for UNION ALL */
        const UNION_ALL = true;
@@ -1011,6 +1013,7 @@ interface IDatabase {
         * @param string $valuename
         *
         * @return string
+        * @deprecated Since 1.33
         */
        public function aggregateValue( $valuedata, $valuename = 'value' );
 
@@ -1109,6 +1112,25 @@ interface IDatabase {
                $options = [], $join_conds = []
        );
 
+       /**
+        * Construct a LIMIT query with optional offset. This is used for query
+        * pages. The SQL should be adjusted so that only the first $limit rows
+        * are returned. If $offset is provided as well, then the first $offset
+        * rows should be discarded, and the next $limit rows should be returned.
+        * If the result of the query is not ordered, then the rows to be returned
+        * are theoretically arbitrary.
+        *
+        * $sql is expected to be a SELECT, if that makes a difference.
+        *
+        * @param string $sql SQL query we will append the limit too
+        * @param int $limit The SQL limit
+        * @param int|bool $offset The SQL offset (default false)
+        * @throws DBUnexpectedError
+        * @return string
+        * @since 1.34
+        */
+       public function limitResult( $sql, $limit, $offset = false );
+
        /**
         * Returns true if DBs are assumed to be on potentially different servers
         *