Sets the last field of a column to a value if the value does not exist in the column.


vtc.sendIfUnique ( columnname, value );
ExampleData Update Functions


columnName The name of the column.
valueThe string to write to the field.

vtc.sendIfUnique sets the last field of a column to a value if the value does not exist in the column. If the value already exists in the column, the function has no effect.

If a column is not indexed, the time required to execute a vtc.sendIfUnique call increases with the number of rows. If the column is indexed, the time for 'send if unique' operations is constant. For large databases, we recommend that you index columns you want to perform 'send if unique' operations on. See vtc.ensureIndex

Return Values

Returns zero on success or one of the Error Codes.


All string input arguments can be passed using standard parameterization.


function callback(){
    var name = 'x' + arguments.callee.caller.arguments.callee.caller;
    lr.message( name.match(',(.*)_wrapper')[1] + '\'s callback arg:');
    for(var i=0 ;i<arguments.length; ++i){
        lr.message( 'arg[' + i + '] type: ' + typeof arguments[i] + ' =' + arguments[i]);

function Action()
    var handle2 = vtc.connect('321.321.321.321', 8889, vtc.VTOPT_KEEP_ALIVE);
    var handle1 = vtc.connect('', 8888, vtc.VTOPT_KEEP_ALIVE);  
    lr.message('handle1: '+ handle1.handle + ' handle2: ' + handle2.handle);
        handle2.createColumn('CID_2', callback );  
        handle2.updateMessage('CID_2', 1, 'bbbb', callback );       
        handle1.createColumn('CID_1', callback );
        handle1.sendMessage('CID_1', '111', callback );
        handle1.sendMessage('CID_1', '2222', callback );
        handle1.updateMessage('CID_1', 1, 'aaaaa', callback );
        handle1.columnSize('CID_1', callback );
        handle1.queryColumn('CID_1', 1, callback );     
        handle1.rotateRow(vtc.VTSEND_SAME_ROW, callback );
        handle1.queryRow(1, callback ); 
        handle1.rotateMessage('CID_1', vtc.VTSEND_SAME_ROW, callback );
        handle1.rotateMessages1('CustomerID,CompanyName', ',', vtc.VTSEND_SAME_ROW, callback );
        handle1.clearColumn('CID_1', callback );        
        handle1.getLastError( callback );
        handle1.disconnect( callback );
        handle2.disconnect( callback );