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SETCURRENTKEY Function (Record)

  • Artículo

Selects a key for a table.

[Ok :=] Record.SETCURRENTKEY(Field1, [Field2],...)

Parameters

  • Record
    Type: Record The record that contains the fields that identify the key that you want to select.
  • Field1, Field2, …
    Type: Field One or more fields that identify the key that you want to select.

Property Value/Return Value

Type: Boolean

true if the key was selected; otherwise, false.

If you omit this optional return value and if the key cannot be found, then a run-time error occurs. If you include a return value, then you must handle any errors.

Remarks

SETCURRENTKEY is used to select a key for a record and set the sort order that is used for the table in question. This key becomes the current key and is used by the FIND Function (Record), the NEXT Function (Record), and other functions until another key is selected. Until this function is called, the table's primary key is used as the current key.

In Microsoft Dynamics NAV 2013, the CALCFIELDS Function (Record), CALCSUMS Function (Record), AND CALCSUM Function (FieldRef) do not require that a SIFT index is defined for the fields that are being calculated. Therefore, you do not need to define keys solely for SIFT indexes. Fewer SIFT indexes and fewer keys can improve performance. In earlier versions of Microsoft Dynamics NAV, if a Microsoft Dynamics NAV key that started with the fields that you specified as parameters to SETCURRENTKEY did not exist, then you received an error when you called the SETCURRENTKEY function. This provided a degree of protection in earlier versions against accidentally requesting a sorting for which no index existed. In Microsoft Dynamics NAV 2013, an index is not required to support a certain sorting, but sorting without an index could lead to bad performance if a search returns a large result set, which would then have to be sorted before the first row is returned.

Use the following guidelines when you use SETCURRENTKEY:

  • Inactive fields are ignored. Only active keys are scanned.

  • When searching for a key, Microsoft Dynamics NAV selects the first occurrence of the specified field(s). This means the following:

    • If you specify only one field as a parameter when you call SETCURRENTKEY, then the key that is actually selected may consist of more than one field.

    • If the field that you specify is the first component of several keys, then the key that is selected is the first one that matches, which may not be the key that you expect.

  • If no keys can be found that include the field(s) that you specify, then a run-time error occurs unless you test the Boolean return value of SETCURRENTKEY in your code.

  • If you do test the return value, then you must decide what to do if the function returns false, because without a run-time error, the application continues to run even though no key was found and may fail later.

  • Use only the necessary key fields in a call to SETCURRENTKEY. If the definition of the key includes the fields that you specify in the call to SETCURRENTKEY in the order given, then you can change the definition of the key without having to change any code. If the table order is not important, then consider one of the following:

    • If the expected result set is small, then do not call SETCURRENTKEY at all. The result will be sorted according to the smallest possible key, which is the primary key.

    • If the expected result set is large, then call SETCURRENTKEY with a field set that matches subsequent calls to SETRANGE and SETFILTER functions. This way, there is less risk that extra sorting of the large result must be done.

Example

This example shows how to use the SETCURRENTKEY function without using a return value. This example requires that you create the following variable.

Name DataType Subtype

MyCustomer

Record

Customer

 
MyCustomer.SETCURRENTKEY(Name);

This statement selects the Name key for the Customer table. If the key cannot be found, a run-time error occurs.

Example

This example shows how to use the SETCURRENTKEY function with a return value.

This example requires that you create the following variable.

Name DataType Subtype

MyCustomer

Record

Customer

This example requires that you create the following text constants.

Name ConstValue

Text000

The key was successfully selected.

Text001

The key could not be found.

 
IF MyCustomer.SETCURRENTKEY(Name) THEN
  MESSAGE(Text000)
ELSE
  MESSAGE(Text001);

By including a return value, you can avoid a run-time error if a key cannot be found.

See Also

Reference

Record Data Type