4D Doc Center : Using the Record Stack

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4D v14.3

Using the Record Stack

The PUSH RECORD and POP RECORD commands allow you to put (“push”) records onto the record stack, and to remove (“pop”) them from the stack.

Each process has its own record stack for each table. 4D maintains the record stacks for you. Each record stack is a last-in-first-out (LIFO) stack. Stack capacity is limited by memory.

PUSH RECORD and POP RECORD should be used with discretion. Each record that is pushed uses part of free memory. Pushing too many records can cause an out-of-memory or stack full condition.

4D clears the stack of any unpopped records when you return to the menu at the end of execution of your method.

PUSH RECORD and POP RECORD are useful when you want to examine records in the same file during data entry. To do this, you push the record, search and examine records in the file (copy fields into variables, for example), and finally pop the record to restore the record.

While entering a record, if you have to check a multiple field unique value, use the SET QUERY DESTINATION command. This will save you the calls to PUSH RECORD and POP RECORD that you were making before and after the call to QUERY in order to preserve the data entered in the current record. SET QUERY DESTINATION allows you to make a query that does not change the selection nor the current record.