Release 10.1A: OpenEdge Development:
Progress 4GL Reference


FIND-UNIQUE( ) method

Gets a single record. This method lets a user get a unique record that satisfies the predicate expression.

Return type: LOGICAL

Applies to: Buffer object handle

Syntax
FIND-UNIQUE ( predicate-expression [ , lockmode [ , wait-mode ] ] ) 

predicate-expression

A character expression that evaluates to the following syntax:

[ WHERE [ logical-expression ] ] [ USE-INDEX index-name ] 

Once evaluated, predicate-expression can contain only constants and unabbreviated references to fields from the buffer. The predicate-expression itself can be built using a concatenation of character expressions.

lockmode

An integer expression evaluating to one of the following constants: SHARE-LOCK, EXCLUSIVE-LOCK, or NO-LOCK. You can assign NO-LOCK to an integer variable. For example, mylock = NO-LOCK.

The default is SHARE-LOCK.

waitmode

An integer expression evaluating to one of the following: NO-WAIT, 0, or the Unknown value (?). The default is to wait.

You can assign NO-WAIT to an integer variable. For example, mywait = NO-WAIT.

The following shows some examples of the FIND-UNIQUE method:

DEFINE VARIABLE bh AS HANDLE. 
DEFINE VAR myname as char 
bh = BUFFER customer:HANDLE. 
bh:FIND-UNIQUE("where cust-num < 3 and name = 'lift line skiing'"). 
bh:FIND-UNIQUE("where cust-num = 30"). 
  
bh:FIND-UNIQUE("where name = " + QUOTER(myname). 
MESSAGE bh:AMBIGUOUS. 

If FIND-UNIQUE succeeds, it returns TRUE, otherwise it returns FALSE.

If FIND-UNIQUE fails, a message displays. You can suppress this message using NO-ERROR on the statement containing the method.

If more than one record satisfies the predicate expression, then the AMBIGUOUS attribute is set to TRUE.

See also

FIND-FIRST( ) method, FIND-CURRENT( ) method, FIND-LAST( ) method, FIND statement


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