Insert, Modify, ModifyAll, Delete, and DeleteAll Methods

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

• Insert
• Modify
• ModifyAll
• Delete
• DeleteAll

These methods are some of the most frequently used AL methods.

Some of these methods return an optional Boolean value that indicates whether the method succeeded. If you do not handle the return value in your code, a run-time error occurs when a method 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 method

The Insert method inserts a record in a table. Insert has the following syntax.

[Ok := ]  Record.Insert([RunTrigger: Boolean[, InsertWithSystemId: Boolean]])

A record must be assigned a SystemId. You have the option to assign your own value or have the platform assign an auto-generated value. The following example inserts a new record, with the SystemId, 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.

var
    Customer: Record Customer;
begin
    Customer.Init;
    Customer.SystemId := '{B6666666-F5A2-E911-8180-001DD8B7338E}';  
    Customer."No." := '4711';  
    Customer.Name := 'Andrew Dixon';  
    Customer.Insert(false, true);
end; 

Modify method

Modify modifies a record that already exists. For more information, see Modify Method. 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.

Customer.Get('4711');  
Customer.Name := 'Richard Roe';  
Customer.Modify;  

ModifyAll method

ModifyAll performs a bulk update of records. For more information, see ModifyAll Method.

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.

Customer.SetRange("Salesperson Code",'PS','PS');  
Customer.ModifyAll("Salesperson Code",'JR');  

Delete method

Delete deletes a record from the database. For more information, see Delete Method 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 method. 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.

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:

1. Retrieve a record from the database.

2. Perform various checks to determine whether the record should be deleted.

3. 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 method. LockTable should be used sparingly because this method degrades performance. For more information about the LockTable method, see LockTable Method.

DeleteAll method

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. For more information, see DeleteAll Method 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.

Customer.SetRange("Salesperson Code", 'PS', 'PS');  
Customer.DeleteAll;  

See Also

AL Methods
SystemId Field