Chapter 5 Building Triggers and Procedures

What are trigger template items?

Trigger template items are named reusable blocks of script that can be inserted into trigger templates or triggers.

In a generated trigger script, a template item calls a macro that implements a trigger referential integrity constraint or does any other updating work on tables in the database.

Example

A trigger template for Sybase Adaptive Server Anywhere 6 contains the .InsertChildParentExist template item, which corresponds to the following definition:

.FOREACH_PARENT()
/*  Parent "[%PQUALIFIER%]%PARENT%" must exist when inserting a child in "[%CQUALIFIER%]%CHILD%"  */
if (.JOIN("new_ins.%FK% is not null", "", " and", ") then")
begin
   set found = 0;
   select 1
    into  found
    from  dummy
   where  exists (select 1
                   from  [%PQUALIFIER%]%PARENT%
                  where  .JOIN("%PK% = new_ins.%FK%", "and   ", "", ");")
   if found <> 1 then
      message 'Error: Trigger(%TRIGGER%) of table [%QUALIFIER%]%TABLE%';
      message '        Parent code must exist when inserting a child!';
      signal user_defined_exception;
   end if;
end
end if;
.ENDFOR

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