如何把sqlite中某列的最大值取出来，并使取出的数加一

Question

目的：
添加参数时，材料特性ID加一

 string zid = "select max(材料特性ID) from 特性";
 int mid = 1;
 int id = Convert.ToInt32(zid) + mid;
 string str = "'" + txtName.Text + "'," + "'" + txtyunxinglicheng.Text + "'," + "'" + txtyingdu.Text + "'," + "'" + txtlashenqiangdu.Text + "'," + "'" + txtladuanshenchanglv.Text + "'," + "'" + yinsu + "'," + "'" + id + "'";
            string sq = @"Data Source=" + dbPath;
            m = new SQLiteConnection(sq);
            m.Open();
            string sql = "insert into " + tableName + " (传感器型号,运行里程,硬度,拉伸强度,拉断伸长率,因素,材料特性ID) values (" + str + ")";
            SQLiteCommand command = new SQLiteCommand(sql, m);
            command.ExecuteNonQuery();
            m.Close();

调试时int id = Convert.ToInt32(zid) + mid;id处显示为0，Convert.ToInt32(zid)好像没转换成功我该怎么改

Answer 1

需要执行sql语句调出值，也就是需要执行zid这个语句