sqlite帮助类

帮助类

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SQLite;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace 数据链接
{
   public static class Sqllite
    {
        #region 样本
       private static readonly string defaultConnectString = "Data Source=" + @"../../Properties/db_name.db";       
        #endregion
        #region 变量
       private static SQLiteConnection _con = null;
       public static string _constr = "Data Source=" + @"../../Properties/db_name.db";             
        #endregion
        #region 属性

        public static string constr
        {
            get
            {
                if (_constr == null || _constr.Equals(String.Empty))
                {
                    _constr = defaultConnectString;
                }
                return _constr;
            }
            set
            {
                _constr = value;
            }
        }

        /// <summary>  
        /// 获取或设置数据库连接对象  
        /// </summary>  
        public static SQLiteConnection Con
        {
            get
            {

                if (Sqllite._con == null)
                {
                    Sqllite._con = new SQLiteConnection();
                }
                if (Sqllite._con.ConnectionString == null || Sqllite._con.ConnectionString.Equals(string.Empty))
                {
                    Sqllite._con.ConnectionString = Sqllite.constr;
                }
                return Sqllite._con;
            }
            set
            {
                Sqllite._con = value;
            }
        }
        #endregion

        /// <summary>
        /// 获取数据表
        /// </summary>
        /// <param name="commandText">select命令</param>
        /// <param name="param">参数表</param>
        /// <returns></returns>
        #region MyRegion
        public static DataTable GetDataTable(string commandText, params SQLiteParameter[] param)
        {
            DataTable result = new DataTable();
            try
            {
                using (SQLiteCommand cmd = new SQLiteCommand(commandText, Sqllite.Con))
                {
                    if (param != null)
                        cmd.Parameters.AddRange(param);
                    try
                    {
                        SQLiteDataAdapter adapter = new SQLiteDataAdapter(cmd);
                        adapter.Fill(result);
                    }
                    catch (Exception ex)
                    {
                        result = null;
                    }
                }
            }
            finally
            {
                if (Sqllite.Con.State != ConnectionState.Closed)
                {
                    Sqllite.Con.Close();
                }
            }
            return result;
        }
        #endregion


        /// <summary>  
        /// 执行不查询的数据库操作  
        /// </summary>  
        /// <param name="commandText">Oracle语句或存储过程名</param>  
        /// <param name="commandType">Oracle命令类型</param>  
        /// <param name="param">Oracle命令参数数组</param>  
        /// <returns>受影响的行数</returns>  
        #region MyRegion
        public static int ExecuteNonQuery(string commandText, CommandType commandType, params SQLiteParameter[] param)
        {
            int result = 0;
            try
            {
                using (SQLiteCommand cmd = new SQLiteCommand(commandText, Sqllite.Con))
                {
                    try
                    {
                        //cmd.CommandType = commandType;
                        if (param != null)
                        {
                            cmd.Parameters.AddRange(param);
                        }
                        Sqllite.Con.Open();
                        result = cmd.ExecuteNonQuery();
                    }
                    catch (Exception ex)
                    {
                        result = -1;
                    }
                }
            }
            finally
            {
                if (Sqllite.Con.State != ConnectionState.Closed)
                {
                    Sqllite.Con.Close();
                }
            }
            return result;
        }
        #endregion
      
    }
}

调用

  /// <summary>
        /// sqlite增删改查
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button3_Click(object sender, EventArgs e)
        {
            DataTable dt = new DataTable();//DataTable接收传回的数据
            dt = Sqllite.GetDataTable("select * from TBL_LANDSLIP;", null);//查询
         //   Sqllite.ExecuteNonQuery(@"INSERT INTO ZLCB01A (ZLCB01A005) VALUES('912')", CommandType.Text, null);//增加
          //  Sqllite.ExecuteNonQuery("delete from  ZLCB01A WHERE ZLCB01A005='955'", CommandType.Text, null);//删除
          //  Sqllite.ExecuteNonQuery(@"update  ZLCB01A SET ZLCB01A005='955' where ZLCB01A005='912'", CommandType.Text, null);//修改
        }