Add PostgreSQL version of SQLite integ tests

- Add PostgreSQL throwaway database
- Add optional length parameter for random string
- Fix syntax for PostgreSQL in several areas
- Add optional ID for whereById type determination

src/Query/RemoveFields.php

@@ -26,7 +26,8 @@ class RemoveFields
     {
         switch (Configuration::$mode) {
             case Mode::PgSQL:
-                return "UPDATE $tableName SET data = data - " . array_keys($parameters)[0] . " WHERE $whereClause";
+                return "UPDATE $tableName SET data = data - " . array_keys($parameters)[0]
+                    . "::text[] WHERE $whereClause";
             case Mode::SQLite:
                 $paramNames = implode(', ', array_keys($parameters));
                 return "UPDATE $tableName SET data = json_remove(data, $paramNames) WHERE $whereClause";
@@ -40,12 +41,13 @@ class RemoveFields
      *
      * @param string $tableName The name of the table in which the document should be manipulated
      * @param array $parameters The parameter list for the query
+     * @param mixed $docId The ID of the document from which fields should be removed (optional; string ID assumed)
      * @return string The UPDATE statement to remove fields from a document by its ID
      * @throws DocumentException If the database mode has not been set
      */
-    public static function byId(string $tableName, array $parameters): string
+    public static function byId(string $tableName, array $parameters, mixed $docId = null): string
     {
-        return self::update($tableName, $parameters, Query::whereById());
+        return self::update($tableName, $parameters, Query::whereById(docId: $docId));
     }
 
     /**