BackTerminal.frmBookMan.tsbSearch_Click C# (CSharp) Method

        private void tsbSearch_Click(object sender, EventArgs e)
        {
            string searchText = txtSearch.Text;
            this.dataSet.readable_book.Clear();

            string sql;
            if (searchText.Length > 0)
                sql = "select * from readable_book where title like @title";
            else
                sql = "select * from readable_book";

            this.readablebookTableAdapter.Adapter.SelectCommand.CommandText = sql;

            this.readablebookTableAdapter.Adapter.SelectCommand.Parameters.Clear();
            if (searchText.Length > 0)
                this.readablebookTableAdapter.Adapter.SelectCommand.Parameters
                    .AddWithValue("@title", "%" + searchText + "%");

            this.readablebookTableAdapter.Fill(dataSet.readable_book);
        }