System.Data.SQLite 不支持多事务 [英] System.Data.SQLite Not Supporting Multiple Transactions

问题描述

所以我在 System.Data.SQLite 和使用多个事务时遇到了一个有趣的问题.基本上我有以下代码失败:

So I am having an interesting issue with System.Data.SQLite and using multiple transactions. Basically I have the following code which fails:

using (IDbConnection connection1 = new SQLiteConnection("connectionstring"), connection2 = new SQLiteConnection("connectionstring"))
{
    connection1.Open();
    connection2.Open();

    IDbTransaction transaction1 = connection1.BeginTransaction();
    IDbTransaction transaction2 = connection2.BeginTransaction();    // Fails!

    using(IDbCommand command = new SQLiteCommand())
    {
        command.Text = "CREATE TABLE artist(artistid int, artistname text);";
        command.CommandType = CommandType.Text;
        command.Connection = connection1;
        command.ExecuteNonQuery();
    }

    using (IDbCommand command = new SQLiteCommand())
    {
        command.Text = "CREATE TABLE track(trackid int, trackname text);";
        command.CommandType = CommandType.Text;
        command.Connection = connection2;                    
        command.ExecuteNonQuery();
    }

    transaction1.Commit();
    transaction2.Commit();

}

从我读到的内容来看，System.Data.SQLite 似乎应该支持嵌套和扩展顺序事务.代码在第 7 行(声明第二个事务的地方)失败，但出现以下异常:

From what I've read it seems that System.Data.SQLite should support nested and by extension sequential transactions. The code fails on line 7 (where the second transaction is declared) with the following exception:

System.Data.SQLite.SQLiteException: The database file is locked

System.Data.SQLite.SQLite3.Step(SQLiteStatement stmt)
System.Data.SQLite.SQLiteDataReader.NextResult()
System.Data.SQLite.SQLiteDataReader..ctor(SQLiteCommand cmd, CommandBehavior behave)
System.Data.SQLite.SQLiteCommand.ExecuteReader(CommandBehavior behavior)
System.Data.SQLite.SQLiteCommand.ExecuteNonQuery()
System.Data.SQLite.SQLiteTransaction..ctor(SQLiteConnection connection, Boolean deferredLock)
System.Data.SQLite.SQLiteConnection.BeginDbTransaction(IsolationLevel isolationLevel)
System.Data.Common.DbConnection.System.Data.IDbConnection.BeginTransaction()

有谁知道问题是什么或如何解决这个问题?我觉得并发事务对于任何数据库系统都是必不可少的，因此必须有某种方法来做到这一点.

Does anyone know what the issue is or how to get around this? I feel having concurrent transactions is essential for any database system so there must be some way to do this.

谢谢！

推荐答案

OP 在 2 个连接上启动事务，这是问题开始的地方，而不是多个事务本身.

OP is initiating transactions on 2 connections, that's where problems start, not multiple transactions per se.

SQLiteConnection conn = new SQLiteConnection("data source=:memory:");
conn.Open();

var command = conn.CreateCommand();
command.CommandText = "create table a (b integer primary key autoincrement, c text)";
command.ExecuteNonQuery();

var tran1 = conn.BeginTransaction();
var tran2 = conn.BeginTransaction();

var command1 = conn.CreateCommand();
var command2 = conn.CreateCommand();

command1.Transaction = tran1;
command2.Transaction = tran2;

command1.CommandText = "insert into a VALUES (NULL, 'bla1')";
command2.CommandText = "insert into a VALUES (NULL, 'bla2')";

command1.ExecuteNonQuery();
command2.ExecuteNonQuery();

tran1.Commit();
tran2.Commit();

command.CommandText = "select count(*) from a";
Console.WriteLine(command.ExecuteScalar());

这篇关于System.Data.SQLite 不支持多事务的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！