SQLite数据库在多线程写锁文件的解决办法

参考了很多SQLITE数据库多线程的解决办法 我自己写了一个SQLITEHELPER 来解决这个问题

希望大家多多指教

调用的时候

 SQLLiteDBHelper _SQLLiteDBHelper = new SQLLiteDBHelper();

 _SQLLiteDBHelper.Dispose();

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

namespace DAL
{
    public class SQLLiteDBHelper : IDisposable
    {
        public static string Connectionstring = "";
        /// <summary>
        /// 获得连接对象
        /// </summary>
        /// <returns></returns>
        public  SQLiteConnection GetSQLiteConnection()
        {
            //return new SQLiteConnection(Connectionstring);
            SQLiteConnection conn = new SQLiteConnection();
            try
            {
  
                conn.ConnectionString = Connectionstring;
                if (conn.State.Equals(ConnectionState.Closed))
                {
                    conn.DefaultTimeout = 5000;
                    conn.Open();
                  
                }
         
            }
            catch (Exception ee)
            {

                //OAFile.ErrorLog(OAFile.GetCurrUrl(), "链接字符串错误，请检查,详细错误：" + ee.Message);
            }
            return conn;
        }

        /// <summary>
        /// COMMAND初始化
        /// </summary>
        /// <param name="cmd"></param>
        /// <param name="conn"></param>
        /// <param name="cmdText"></param>
        /// <param name="p"></param>
        private  void PrepareCommand(SQLiteCommand cmd, SQLiteConnection conn, string cmdText, params object[] p)
        {
            try
            {
                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.Add(parm);
                }
            }
            catch (Exception)
            {
                

            }

        }

        /// <summary>
        /// 批量执行带参数的SQL语句 事务 并返回执行结果
        /// </summary>
        /// <param name="SQLStringList"></param>
        /// <param name="PramsList"></param>
        /// <returns></returns>
        public  string ExecuteSqlTran(List<string> SQLStringList, List<SQLiteParameter[]> PramsList)
        {
            AcquireWriteLock();
            string result = "执行成功";
            using (SQLiteConnection conn = GetSQLiteConnection())
            {
                using (SQLiteCommand cmd = new SQLiteCommand())
                {
                    try
                    {
                        cmd.Connection = conn;
                        SQLiteTransaction tx = conn.BeginTransaction();
                        cmd.Transaction = tx;
                        try
                        {
                            for (int i = 0; i < SQLStringList.Count; i++)
                            {
                                if (SQLStringList[i].Trim().Length > 1)
                                {
                                    PrepareCommand(cmd, conn, SQLStringList[i].Trim(), PramsList[i]);
                                    cmd.ExecuteNonQuery();
                                    cmd.Parameters.Clear();
                                }
                            }
                            tx.Commit();
                        }
                        catch (Exception ex)
                        {
                            tx.Rollback();
                            result = ex.Message.Trim();
                        }
                    }
                    catch (Exception)
                    {

                        result = "lock";
                    }
                  
                }
            }
            return result;
        }

        /// <summary>
        /// 批量执行带参数的SQL语句 事务 并返回执行结果
        /// </summary>
        /// <param name="SQLStringList"></param>
        /// <param name="PramsList"></param>
        /// <returns></returns>
        public  string ExecuteSqlTran(List<string> SQLStringList)
        {
            AcquireWriteLock();
            string result = "执行成功";
            using (SQLiteConnection conn = GetSQLiteConnection())
            {
                using (SQLiteCommand cmd = new SQLiteCommand())
                {
                    cmd.Connection = conn;
                    SQLiteTransaction tx = conn.BeginTransaction();
                    cmd.Transaction = tx;
                    try
                    {
                        for (int i = 0; i < SQLStringList.Count; i++)
                        {
                            if (SQLStringList[i].Trim().Length > 1)
                            {
                                PrepareCommandNoParameters(cmd, conn, SQLStringList[i].Trim());
                                cmd.ExecuteNonQuery();
                               // cmd.Parameters.Clear();
                            }
                        }
                        tx.Commit();
                    }
                    catch (Exception ex)
                    {
                        if (conn.State!=ConnectionState.Closed)
                        {
                            tx.Rollback();
                        }

                        result = ex.Message.Trim();
                    }
                }
            }
            return result;
        }

        /// <summary>
        /// COMMAND初始化
        /// </summary>
        /// <param name="cmd"></param>
        /// <param name="conn"></param>
        /// <param name="cmdText"></param>
        /// <param name="p"></param>
        private  void PrepareCommandNoParameters(SQLiteCommand cmd, SQLiteConnection conn, string cmdText)
        {
            try
            {
                if (conn.State != ConnectionState.Open)
                    conn.Open();
                cmd.Connection = conn;
                cmd.CommandText = cmdText;
                cmd.CommandType = CommandType.Text;
                cmd.CommandTimeout = 30;
            }
            catch (Exception)
            {

            }
        }

        /// <summary>
        /// 返回DataSet
        /// </summary>
        /// <param name="cmdText"></param>
        /// <param name="p"></param>
        /// <returns></returns>
        public  DataSet DS(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;
        }

        /// <summary>
        /// 返回DataTable
        /// </summary>
        /// <param name="cmdText"></param>
        /// <param name="p"></param>
        /// <returns></returns>
        public  DataTable DT(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.Tables[0];
        }

        /// <summary>
        /// 返回DataTable
        /// </summary>
        /// <param name="cmdText"></param>
        /// <param name="p"></param>
        /// <returns></returns>
        public  DataTable DT(string cmdText)
        {
            DataSet ds = new DataSet();
            SQLiteCommand command = new SQLiteCommand();
            using (SQLiteConnection connection = GetSQLiteConnection())
            {
                PrepareCommandNoParameters(command, connection, cmdText);
                SQLiteDataAdapter da = new SQLiteDataAdapter(command);
                da.Fill(ds);
            }
            return ds.Tables[0];
        }

        /// <summary>
        /// 返回执行数据的行数
        /// </summary>
        /// <param name="cmdText"></param>
        /// <param name="p"></param>
        /// <returns></returns>
        public  DataRow ExecuteDataRow(string cmdText, params object[] p)
        {
            DataSet ds = DS(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  int ExecuteNonQuery(string cmdText, params object[] p)
        {
            AcquireWriteLock();
            SQLiteCommand command = new SQLiteCommand();
            using (SQLiteConnection connection = GetSQLiteConnection())
            {
                PrepareCommand(command, connection, cmdText, p);
                return command.ExecuteNonQuery();
            }
        }

        /// <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  int ExecuteNonQuery(string cmdText)
        {
            AcquireWriteLock();
            SQLiteCommand command = new SQLiteCommand();
            using (SQLiteConnection connection = GetSQLiteConnection())
            {

                PrepareCommandNoParameters(command, connection, cmdText);
                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  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  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  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;
        }

        #region 静态字段和属性
        const short WAIT_TIME = 5;
        static readonly object locker = new object();
        static Dictionary<string, int> _dbThreadIdDict = new Dictionary<string, int>();
        /// <summary>
        /// 获得写操作的超时时间，单位为毫秒，可以通过配置文件appSettings节中添加设置 SQLiteWriteLockTimeout 的value值控制锁等待的超时时间，该值必须为正整数数字，单位为毫秒
        /// 默认的超时时间是1000ms
        /// </summary>
        public static int SQLiteWriteLockTimeout
        {
            get
            {
                string configValule = "300000";
                if (!string.IsNullOrEmpty(configValule))
                {
                    return int.Parse(configValule);
                }
                return 1000;
            }
        }
        #endregion

        private  string _connString;

        
        public SQLLiteDBHelper()
        {
        }

        #region 私有方法

        private void AcquireWriteLock()
        {
            if (Connectionstring=="")
            {
                return;
            }
            _connString = Connectionstring;
            int threadId = Thread.CurrentThread.ManagedThreadId;

            int waitTimes = 0;
            while (_dbThreadIdDict.ContainsKey(_connString) && _dbThreadIdDict[_connString] != threadId)
            {
                Thread.Sleep(WAIT_TIME);
                waitTimes += WAIT_TIME;
#if DEBUG
            Console.WriteLine(_connString + " wait for " + waitTimes + " ms");
#endif
                if (waitTimes > SQLiteWriteLockTimeout)
                {
                    //throw new TimeoutException("SQLite等待写操作超时");
                }
            }

            lock (locker)
            {
                if (!_dbThreadIdDict.ContainsKey(_connString))
                    _dbThreadIdDict.Add(_connString, threadId);
            }
        }

        private void ReleaseWriteLock()
        {
            lock (locker)
            {
                if (_connString!=null)
                {
                    if (_dbThreadIdDict.ContainsKey(_connString))
                    {
                        _dbThreadIdDict.Remove(_connString);
                    }
                }

            }
        }

        #endregion

        #region IDisposable 成员

        public void Dispose()
        {
            ReleaseWriteLock();
        }
         #endregion
    }
}