在线急等：如何解决c#多线程写入sqlite的 SQLite error (5): database is locked 错误？

tylrr123 2014-06-02 02:22:44

如题，c#+sqlite数据库。程序使用了多线程调用getlinks 函数，写入数据到sqlite里面，但是程序总是报错：

SQLite error (5): database is locked
SQLite error (5): database is locked
SQLite error (5): database is locked

求解决方法，谢谢！







        #region   //提取搜索结果中的宝贝链接

        private void getlinks(object workmode)

        {

...................省略部分代码



            //写入数据库

            try

            {

                SQLiteConnection mycon = new SQLiteConnection();

                SQLiteConnectionStringBuilder connsb = new SQLiteConnectionStringBuilder();

                connsb.DataSource = dbName;

                mycon.ConnectionString = connsb.ToString();

                mycon.Open();

                for (int i = 0; i < itemlinks.Count; i++)

                {                   

                    SQLiteCommand mycmd = new SQLiteCommand();

                    switch (workmode.ToString())

                    {

                        case "a":

                            mycmd = new SQLiteCommand(string.Format("insert INTO itemdetails(itemid,checkedtime,itemurl) select '{0}','{1}','{2}' where not exists(select itemid,checkedtime from itemdetails where itemid='{0}'); ", getItemid(itemlinks[i]), checkedtime, itemlinks[i]), mycon);

                            mycmd.ExecuteNonQuery();

                            mycmd = new SQLiteCommand(string.Format("update itemdetails set zhrank={0} where itemid={1};", i + 1,getItemid(itemlinks[i])), mycon); 

                            mycmd.ExecuteNonQuery();

                            break;



                        case "b":

                            mycmd = new SQLiteCommand(string.Format("insert INTO itemdetails(itemid,checkedtime,itemurl) select '{0}','{1}','{2}' where not exists(select itemid,checkedtime from itemdetails where itemid='{0}'); ", getItemid(itemlinks[i]), checkedtime, itemlinks[i]), mycon);

                            mycmd.ExecuteNonQuery();

                            mycmd = new SQLiteCommand(string.Format("update itemdetails set rqrank={0} where itemid={1};", i + 1, getItemid(itemlinks[i])), mycon); 

                            mycmd.ExecuteNonQuery();

                            break;



                        case "c":

                            mycmd = new SQLiteCommand(string.Format("insert INTO itemdetails(itemid,checkedtime,itemurl) select '{0}','{1}','{2}' where not exists(select itemid,checkedtime from itemdetails where itemid='{0}'); ", getItemid(itemlinks[i]), checkedtime, itemlinks[i]), mycon);

                            mycmd.ExecuteNonQuery();

                            mycmd = new SQLiteCommand(string.Format("update itemdetails set xlrank={0} where itemid={1};", i + 1, getItemid(itemlinks[i])), mycon); 

                            mycmd.ExecuteNonQuery();

                            break;



                        case "d":

                            mycmd = new SQLiteCommand(string.Format("insert INTO itemdetails(itemid,checkedtime,itemurl) select '{0}','{1}','{2}' where not exists(select itemid,checkedtime from itemdetails where itemid='{0}'); ", getItemid(itemlinks[i]), checkedtime, itemlinks[i]), mycon);

                            mycmd.ExecuteNonQuery();

                            mycmd = new SQLiteCommand(string.Format("update itemdetails set tmrank={0} where itemid={1};", i + 1, getItemid(itemlinks[i])), mycon); 

                            mycmd.ExecuteNonQuery();

                            break;

                    }

                }



                mycon.Close();   //关闭数据库连接

            }



            catch (Exception e)

            {

                MessageBox.Show(e.ToString());

            }