查询数据库工具

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using Mono.Data.Sqlite;

public class DataBaseControl : MonoSingleton<DataBaseControl> {
    /// <summary>
    /// 帮助我们与数据库建立连接
    /// </summary>
    SqliteConnection connection;
    
    /// <summary>
    /// 数据库执行命令对象
    /// </summary>
    SqliteCommand command;

    /// <summary>
    /// 查询结果
    /// </summary>
    SqliteDataReader reader;
    

    public DataBaseControl()
    {
#if UNITY_EDITOR
        string datePath = "Data Source=" + Application.dataPath + "/" + "MySqliteTest.sqlite;Pooling=true";

#elif UNITY_IPHONE
        string dataPath="Data Source="+Application.persistentDataPath+"/"+"MySqliteTest.sqlite";
#endif
        try
        {
            if (connection == null)
            {
                connection = new  SqliteConnection (datePath);
            }
        }
        catch (SqliteException ex)
        {
            Debug.Log(ex);
        }
        try
        {
            command = connection.CreateCommand();
        }
        catch (SqliteException ex)
        {
            Debug.Log(ex);
        }
    }
    

    /// <summary>
    /// 打开数据库
    /// </summary>
    private void OpenDataBase()
    {
        try
        {
            connection.Open();
        }
        catch (SqliteException ex)
        {
            Debug.Log(ex);
            
        }
    }
    /// <summary>
    /// 关闭数据库
    /// </summary>
    private void CloseDataBase()
    {
        try
        {
            connection.Close();
        }
        catch (SqliteException ex)
        {
            Debug.Log(ex);

        }
    }


    //ExecuteNonQuery() 没有返回值
    //

    /// <summary>
    /// 执行 不返回数据
    /// </summary>
    /// <param name="sql"></param>
    public void ExecSql(string sql)
    {
        OpenDataBase();

        try
        {
            command.CommandText = sql;
            command.ExecuteNonQuery();
           
        }
        catch (SqliteException ex)
        {

            throw;
        }

        CloseDataBase();
    }

    /// <summary>
    /// 返回第一条数据
    /// </summary>
    /// <param name="sql"></param>
    /// <returns></returns>
    public object SelectFileSql(string sql)
    {
        OpenDataBase();

        object obj = null;
        try
        {
            command.CommandText = sql;
            obj = command.ExecuteScalar();
        }
        catch (SqliteException ex)
        {

            Debug.Log(ex);
        }

        CloseDataBase();
        return obj;
    }
    /// <summary>
    /// 返回第一条  并返回一个0  和1 的数字，代表返回的数据是否为空
    /// </summary>
    /// <param name="sql"></param>
    /// <param name="hasResult"></param>
    /// <returns></returns>
    public object SelectFileSql(string sql ,out int hasResult)
    {
        OpenDataBase();

        object obj = null;
        hasResult = 0;
        try
        {
            command.CommandText = sql;
            obj = command.ExecuteScalar();
            hasResult = obj.GetType() == typeof(System.DBNull) ? 0 : 1;
        }
        catch (SqliteException ex)
        {

            Debug.Log(ex);
        }

        CloseDataBase();
        return obj;
    }

    /// <summary>
    /// 执行返回所有数据
    /// </summary>
    /// <param name="sql"></param>
    /// <returns></returns>
    public List<ArrayList > SelectResultSql(string sql)
    {
        OpenDataBase();
        List<ArrayList> list = new List<ArrayList>();

        try
        {
            command.CommandText = sql;
            reader = command.ExecuteReader();

            while (reader.Read())
            {
                ArrayList alist = new ArrayList();
                for (int i = 0; i < reader.FieldCount; i++)
                {
                    alist.Add(reader.GetValue(i));

                }
                list.Add(alist);
            }
        }
        catch (SqliteException ex)
        {
            Debug.Log(ex);
            
        }
        reader.Close();


        CloseDataBase();
        return list;
    }
}