C#操作SQLite的辅助类

2021-11-02 14:40:44 浏览数 (1)

SQLite这个精巧的小数据库,无需安装软件,只需要一个System.Data.SQLite.DLL文件即可操作SQLite数据库。SQLite是 一个开源数据库,现在已变得越来越流行,它的体积很小,被广泛应用于各种不同类型的应用中。

代码语言:javascript复制
using System;

using System.Collections.Generic;

using System.Text;

using System.Web;

using System.Configuration;

using System.Data;

using System.Data.SQLite;



namespace DAL

{

    public class Sqlite

    {

        /// <summary>

        /// 获得连接对象

        /// </summary>

        /// <returns></returns>

        public static SQLiteConnection GetSQLiteConnection()

        {

            return new SQLiteConnection("Data Source="   System.Web.HttpContext.Current.Server.MapPath(System.Configuration.ConfigurationManager.AppSettings["db"].ToString()));

        }



        private static void PrepareCommand(SQLiteCommand cmd, SQLiteConnection conn, string cmdText, params object[] p)

        {



            if (conn.State != ConnectionState.Open)

                conn.Open();

            cmd.Parameters.Clear();

            cmd.Connection = conn;

            cmd.CommandText = cmdText;



            cmd.CommandType = CommandType.Text;

            cmd.CommandTimeout = 30;



            if (p != null)

            {

                foreach (object parm in p)

                    cmd.Parameters.AddWithValue(string.Empty, parm);

                //for (int i = 0; i < p.Length; i  )

                //    cmd.Parameters[i].Value = p[i];

            }

        }



        public static DataSet ExecuteDataset(string cmdText, params object[] p)

        {

            DataSet ds = new DataSet();

            SQLiteCommand command = new SQLiteCommand();

            using (SQLiteConnection connection = GetSQLiteConnection())

            {

                PrepareCommand(command, connection, cmdText, p);

                SQLiteDataAdapter da = new SQLiteDataAdapter(command);

                da.Fill(ds);

            }



            return ds;

        }



        public static DataRow ExecuteDataRow(string cmdText, params object[] p)

        {

            DataSet ds = ExecuteDataset(cmdText, p);

            if (ds != null && ds.Tables.Count > 0 && ds.Tables[0].Rows.Count > 0)

                return ds.Tables[0].Rows[0];

            return null;

        }



        /// <summary>

        /// 返回受影响的行数

        /// </summary>

        /// <param name="cmdText">a</param>

        /// <param name="commandParameters">传入的参数</param>

        /// <returns></returns>

        public static int ExecuteNonQuery(string cmdText, params object[] p)

        {

            SQLiteCommand command = new SQLiteCommand();



            using (SQLiteConnection connection = GetSQLiteConnection())

            {

                PrepareCommand(command, connection, cmdText, p);

                return command.ExecuteNonQuery();

            }

        }



        /// <summary>

        /// 返回SqlDataReader对象

        /// </summary>

        /// <param name="cmdText"></param>

        /// <param name="commandParameters">传入的参数</param>

        /// <returns></returns>

        public static SQLiteDataReader ExecuteReader(string cmdText, params object[] p)

        {

            SQLiteCommand command = new SQLiteCommand();

            SQLiteConnection connection = GetSQLiteConnection();

            try

            {

                PrepareCommand(command, connection, cmdText, p);

                SQLiteDataReader reader = command.ExecuteReader(CommandBehavior.CloseConnection);

                return reader;

            }

            catch

            {

                connection.Close();

                throw;

            }

        }



        /// <summary>

        /// 返回结果集中的第一行第一列,忽略其他行或列

        /// </summary>

        /// <param name="cmdText"></param>

        /// <param name="commandParameters">传入的参数</param>

        /// <returns></returns>

        public static object ExecuteScalar(string cmdText, params object[] p)

        {

            SQLiteCommand cmd = new SQLiteCommand();



            using (SQLiteConnection connection = GetSQLiteConnection())

            {

                PrepareCommand(cmd, connection, cmdText, p);

                return cmd.ExecuteScalar();

            }

        }



        /// <summary>

        /// 分页

        /// </summary>

        /// <param name="recordCount"></param>

        /// <param name="pageIndex"></param>

        /// <param name="pageSize"></param>

        /// <param name="cmdText"></param>

        /// <param name="countText"></param>

        /// <param name="p"></param>

        /// <returns></returns>

        public static DataSet ExecutePager(ref int recordCount, int pageIndex, int pageSize, string cmdText, string countText, params object[] p)

        {

            if (recordCount < 0)

                recordCount = int.Parse(ExecuteScalar(countText, p).ToString());



            DataSet ds = new DataSet();



            SQLiteCommand command = new SQLiteCommand();

            using (SQLiteConnection connection = GetSQLiteConnection())

            {

                PrepareCommand(command, connection, cmdText, p);

                SQLiteDataAdapter da = new SQLiteDataAdapter(command);

                da.Fill(ds, (pageIndex - 1) * pageSize, pageSize, "result");

            }

            return ds;

        }

    }

}

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