Traps exist for triggers

A trigger is a special kind of stored procedure that cannot be called explicitly and is automatically activated only when an INSERT, UPDATE, delete operation is made to a table. So triggers can be used to implement complex integrity constraints on a table.

SQL Server creates two dedicated tables for each trigger: the inserted table and the deleted table. These two tables are maintained by the system, and they exist in memory rather than in the database. The structure of the two tables is always the same as the structure of the table to which the trigger is executed, and the two tables associated with the trigger are also deleted when the trigger is completed.

Operations on a table	Inserted logic table	Deleted logic Table
Add record (insert)	Storage of Added Records	No
Delete a record (delete)	No	To store deleted records
Modify record (update)	Storage of updated records	Store pre-update records

TRAPS: Update triggers are only triggered once by update, regardless of the number of records updated

Alter TRIGGERDbo.tmp_table1_update onTmp_table1 AfterUPDATE   as  SELECT *  into#INS fromINSERTEDDECLARE @PersonCode VARCHAR( -),@Amount  Money  IF UPDATE(Amount)BEGIN      DECLAREAmountcursorCURSOR  for      SELECTPersoncode,amount from#INSOPENAmountcursorFETCH NEXT  fromAmountcursor into @PersonCode,@Amount       while @ @FETCH_STATUS=0      BEGIN          UPDATETmp_table2SETAmount=@Amount WHEREPersoncode=@PersonCode          FETCH NEXT  fromAmountcursor into @PersonCode,@Amount      END      CLOSEAmountcursordeallocateAmountcursorEND  

Traps exist for triggers