SQL Reference

DLVALUE

>>-DLVALUE--(--data-location------------------------------------>
 
>----+---------------------------------------------+--)--------><
     '-,--linktype-string--+--------------------+--'
                           '-,--comment-string--'
 

The schema is SYSIBM.

The DLVALUE function returns a DATALINK value. When the function is on the right hand side of a SET clause in an UPDATE statement or is in a VALUES clause in an INSERT statement, it usually also creates a link to a file. However, if only a comment is specified (in which case the data-location is a zero-length string), the DATALINK value is created with empty linkage attributes so there is no file link.

data-location

If the link type is URL, then this is an expression that yields a varying length character string containing a complete URL value.

linktype-string

An optional VARCHAR expression that specifies the link type of the DATALINK value. The only valid value is 'URL' (SQLSTATE 428D1).

comment-string

An optional VARCHAR(254) value that provides a comment or additional location information.

The result of the function is a DATALINK value. If any argument of the DLVALUE function can be null, the result can be null; If the data-location is null, the result is the null value.

When defining a DATALINK value using this function, consider the maximum length of the target of the value. For example, if a column is defined as DATALINK(200), then the maximum length of the data-location plus the comment is 200 bytes.

Example:

• Insert a row into the table. The URL values for the first two links are contained in the variables named url_article and url_snapshot. The variable named url_snapshot_comment contains a comment to accompany the snapshot link. There is, as yet, no link for the movie, only a comment in the variable named url_movie_comment.

    EXEC SQL  INSERT INTO HOCKEY_GOALS
                VALUES('Maurice Richard',
                      'Montreal Canadien',
                      '?',
                      'Boston Bruins,
                      '1952-04-24',
                      'Winning goal in game 7 of Stanley Cup final',
                       DLVALUE(:url_article),
                       DLVALUE(:url_snapshot, 'URL', :url_snapshot_comment),
                       DLVALUE('', 'URL', :url_movie_comment) );