我创建一个addata数据表连接数据库是成功的，现在需要用unity删除表和更新表的内容。应该是数据转换的问题。调试不成功，希望指导解决。数据表的名称为addata，有五项内容did和cid为unit类型。addx、addy、addz为float类型。

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using System;
using Assets;
using MySql.Data.MySqlClient;

public class Test : MonoBehaviour
{
    public float timer = 12;
    //public bool OnTimer = false;
    public float xx;
    // Use this for initialization
    public float yy;
    public float zz;
    private SqlAccess sqlAce;

    MySqlConnection con;
    void Start()
    {

    }

    // Update is called once per frame
    void Update()
    {
        if (Input.GetKeyDown(KeyCode.H))
        {
            // OnTimer = true;
            StartCoroutine(Countdown());
            Debug.Log("ffd");

        }
        //if (OnTimer == true)
        //{

        // }
        if (Input.GetKeyDown(KeyCode.J))
        {
            //StopCoroutine(Countdown());
            //yield return null;
            //   OnTimer = false;
            StopAllCoroutines();
            DeleteInfomation();


        }

    }
    IEnumerator Countdown()
    {
        // xx = this.transform.localPosition.x;
        //InsertInfomation();
        UpdateInfomation();
        while (true)
        {
            yield return new WaitForSeconds(timer);
            //InsertInfomation();
            UpdateInfomation();
        }
    }
 
    public void DeleteInfomation()
    {
        //删除did为0的addx、addy、addz数据。
        sqlAce = new SqlAccess();
        con = SqlAccess.con;
        string sql2 = string.Format("select from addata where did={0}",'0');
        sqlAce.DeleteInfo(sql2, con);
    }
    public void UpdateInfomation()
    {
        //更新did为0的addx、addy、addz数据。
        
        sqlAce = new SqlAccess();
        con = SqlAccess.con;
        xx = this.transform.localPosition.x;
        yy = this.transform.localPosition.y;
        zz = this.transform.localPosition.z;
        string sql =string.Format("update addata set addx={0},addy={1},addz={2}' where did='{3}'",xx,yy,zz,0);
        sqlAce.UpdateInfo(sql, con);
        sqlAce.CloseMySQL();
    }



}