INSERT, MODIFY, MODIFYALL, DELETE, and DELETEALL Functions

Artigo
09/14/2014

The following functions maintain the database by adding, modifying, and removing records:

INSERT
MODIFY
MODIFYALL
DELETE
DELETEALL

These functions are some of the most frequently used C/AL functions.

Some of these functions return an optional Boolean value that indicates whether the function succeeded. If you do not handle the return value in your code, a run-time error occurs when a function returns FALSE. If you handle the return value by testing its value in an IF statement, no error will occur, and you must take corrective action in the code.

INSERT Function

INSERT inserts a record in a table.

INSERT has the following syntax.

[Ok :=] Record.INSERT([RunTrigger])

The following example inserts a new record, with the No. and Name fields specified in the assigned values, while other fields will have their default values. If the No. field is the primary key of the Customer table, then the record will be inserted in the Customer table unless the table already contains a record with the same primary key. In this case you receive an error message because the return value is not tested.

This example requires that you create the following variable.

Variable	Data type	Subtype
Customer	Record	Customer

Customer.INIT;
Customer."No." := '4711';
Customer.Name := 'Andrew Dixon';
Customer.INSERT;

MODIFY Function

MODIFY modifies a record that already exists.

MODIFY has the following syntax.

[Ok :=] Record.MODIFY([RunTrigger])

MODIFY returns an optional Boolean value. It returns TRUE if the record to be modified exists; otherwise, it returns FALSE.

The following example changes the name of customer 4711 to Richard Roe. This example requires that you create the following variable.

Variable	Data type	Subtype
Customer	Record	Customer

Customer.GET('4711');
Customer.Name := 'Richard Roe';
Customer.MODIFY;

MODIFYALL Function

MODIFYALL performs a bulk update of records.

MODIFYALL has the following syntax.

Record.MODIFYALL(Field, NewValue [, RunTrigger])

MODIFYALL uses the current filters. This means that you can perform the update on a specified set of records in a table. MODIFYALL returns no value, nor does it cause an error if the set of records to be changed is empty.

In the following example, the SETRANGE statement selects the records where Salesperson Code is PS. The MODIFYALL statement changes the Salesperson Code of these records to JR. The example requires that you create the following variable.

Variable	Data type	Subtype
Customer	Record	Customer

Customer.SETRANGE("Salesperson Code",'PS','PS');
Customer.MODIFYALL("Salesperson Code",'JR');

DELETE Function

DELETE deletes a record from the database.

DELETE has the following syntax.

[Ok :=] Record.DELETE([RunTrigger])

The record that you want to delete must be specified by using the values in the primary key fields before you call this function. This means that DELETE does take filters into consideration.

The following example shows how to use DELETE to delete the record for customer number 4711. This example requires that you create the following variable.

Variable	Data type	Subtype
Customer	Record	Customer

Customer."No." := '4711';
Customer.DELETE;

DELETE returns an optional Boolean value. It returns TRUE if the record could be found; otherwise, it returns FALSE. Unless you test this value in your code, a run-time error occurs when DELETE fails

When you are developing your own applications, you should consider the following scenario:

Retrieve a record from the database.
Perform various checks to determine whether the record should be deleted.
If step 2 indicated that you should delete the record, then delete it.

This can cause problems in a multi-user environment. Another user can modify or delete the same record between your performing steps 2 and 3. If the record is modified, then perhaps the new contents of the record would have changed your decision to delete it. If it has been deleted by the other user, you can get a run-time error if you have just verified that the record existed (in step 1). If the design of your application indicates that you can encounter this problem, you should consider using the LOCKTABLE function. LOCKTABLE should be used sparingly because this function degrades performance. For more information about the LOCKTABLE function, see LOCKTABLE Function.

DELETEALL Function

DELETEALL deletes all the records that are specified by the filter settings. If no filters are applied, it deletes all the records in the table.

DELETEALL has the following syntax.

Record.DELETEALL([RunTrigger])

The following example deletes all the records from the Customer table where the Salesperson Code is PS. This example requires that you create the following variable.

Variable	Data type	Subtype
Customer	Record	Customer

Customer.SETRANGE("Salesperson Code", 'PS', 'PS');
Customer.DELETEALL;

Note

When you use DELETEALL(TRUE), Microsoft Dynamics NAV creates a copy of the C/AL variable with its initial values. This means that when you use DELETEALL(TRUE) to run the OnDelete trigger, all the changes that were made to the variables in the function or codeunit that is making the call cannot be seen in the OnDelete trigger. If you want to see the changes that you made to the variables, you must use DELETE(TRUE) in a loop. There is no difference in performance between using DELETEALL(TRUE) and using DELETE(TRUE) in a loop.

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