Chapter 13 How MySQL Transforms Subqueries

Table of Contents     [+/-]

13.1 Item_in_subselect::select_transformer     [+/-]

13.1.1 Scalar IN Subquery

13.1.2 Row IN Subquery

13.2 Item_allany_subselect

13.3 Item_singlerow_subselect

The Item_subselect virtual method select_transformer is used to rewrite subqueries. It is called from Item_subselect::init (which is called just after the call to the fix_fields() method for all items in JOIN::prepare).