instead, we use two entities A and B that are both NULL. A and B may be fields, variables, or even composite subexpressions — as long as they’re NULL, they’ll all behave the same in the enclosing expressions

has been aliased, it is the alias, not the original name, that must be used in the PLAN clause. Composite plans When a join is made, you can specify the index which is to be used for matching. You must specified columns. If the primary or unique key referenced by the foreign key of the other table is composite then all columns of the key must be specified. ALL Combines SELECT, INSERT, UPDATE, DELETE and

has been aliased, it is the alias, not the original name, that must be used in the PLAN clause. Composite plans When a join is made, you can specify the index which is to be used for matching. You must specified columns. If the primary or unique key referenced by the foreign key of the other table is composite then all columns of the key must be specified. ALL [PRIVILEGES] Combines SELECT, INSERT, UPDATE