[Casimiro Noteví]

Código Delphi [-]
 Query1.Close;
  if edit1.text<>'' then
      query1.SQL.text:='SELECT * FROM proveedores WHERE Proveedor like ' + QuotedStr(Edit1.Text + '%')
  else
      query1.SQL.text:='SELECT * FROM proveedores';  
  Query1.Open;