c# - Search DataGridView using search query and like operator -

i want search name in datagridview using search query , like operator.

 public static dataset searchitems(string key)     {         string cmd = @"select lt.ledgerid,la.ledgername ledgertranscationinfo lt                                   join ledgeraccreation la on lt.ledgerid = la.ledgerid;                                                             la.ledgername concat('"                                 + key.trim() + "','%') ;";         dataset ds = mysql_helper.getdataset(commandtype.text, cmd, "ledgeraccreation");         return ds;     } 

it show error while searching text. please give me proper solution text search.