Security/Guides/SQL Queries and 3rd Party Packages

SQL Queries
Connecting your application and database layers can pose security risks. Notably, SQL injection. Below is an outline of the do's and dont's of executing SQL queries in MediaWiki.

Always Incorrect
MediaWiki developers should never directly execute SQL queries through PHP's database extension functions (such as  or  ).

Why? Directly inserting a SQL string in one of these provided functions makes the developer responsible for escaping the SQL string themselves. Otherwise, applications are susceptible to SQL injection attacks.

De-Facto
Most of the time, developers can us existing wrapper functions like  or   to perform SQL queries. When supplying input to these wrapper functions, it is important to use  on raw user data, as it correctly escapes the provided input (such as table name and  /  statements) to prevent SQL injection.

MW >1.35
As of MediaWiki 1.35, developers should use the SelectQueryBuilder class to create SQL  statements. This class allows function chaining so SQL queries are easily readable and don't require specifically formatted input parameters (like  does). The parameters to SelectQueryBuilder wrapper functions such as SelectQueryBuilder::where should also be escaped via  before being passed in.

Custom Queries
Rarely, you may need to execute a custom SQL query, one that does not fit within the parameters of the IDatabase wrapper functions or the  in which case you can use. This is useful for queries that are explicitly DBMS-dependent and are unsupported by the query wrappers such as.