Restrictions

Restrictions

1. On stored programs

   • Lock/Unlock Tables, Alterview, Load Data/Table

2. Stored functions.

   • Flush, Select, Into, show, explain, check table
   • Stored functions cannot be used recursively.
   • A stored function or trigger cannot modify a table that is already being used (for reading or writing) by the statement that invoked the function or trigger.

3. Triggers

   • are not activated by foreign key actions.
   • Return/leave
     • not permitted in triggers, which cannot return a value. To exit a trigger immediately, use the LEAVE statement.

4. Name conflicts

   • The same identifier might be used for a routine parameter, a local variable, and a table column. Also, the same local variable name can be used in nested blocks.
     • A local variable takes precedence over a routine parameter or table column.
     • A routine parameter takes precedence over a table column.
     • A local variable in an inner block takes precedence over a local variable in an outer block.