Specifying update when key is modified

The Key Modification property determines the SQL statements InfoMaker generates whenever a key column -- a column you specified in the Unique Key Columns box -- is changed. The options are:

  • Use DELETE then INSERT (default)

  • Use UPDATE

How to choose a setting

Consider the following when choosing the Key Modification setting:

  • If multiple rows are changed, DELETE and INSERT always work. In some DBMSs, UPDATE fails if the user modifies two keys and sets the value in one row to the original value of the other row.

  • You might choose the setting here based on your DBMS triggers. For example, if there is an Insert trigger, select Use Delete then Insert.

  • If only one row can be modified by the user before the database is updated, use UPDATE because it is faster.