Manual:SQL patch file

You might write an SQL file either for a schema change in the core (see policy>Special:MyLanguage/Development_policy#Database_patches|Development_policy#Database_patches, ) or for an extension (see ).

Example
An SQL file to create a table might look something like this:

Variable replacement
will be replaced with $wgDBprefix;  will be replaced with an index prefix;   will be replaced with the value of $wgDBTableOptions. These three need to be used in patch files, as in the example above. There are other variable replacements but they are not used in practice; see the documentation of DatabaseBase::replaceVars for the full list.