multiple update statements throw “cannot open”

夙愿已清 提交于 2019-12-12 18:26:56

问题


I am getting a "cannot open" exception when I try to do multiple updates on the same table in the same transaction on SQLite in WinRT.

I have created a sample application for this use case. Below is code where on clicking the first button, I am creating a table in a transaction, and on clicking the other button, I am trying to update the same record a second time. There, it throws a "cannot open" exception.

app code:

private SQLiteConnection getConnection()
{
    var connection = SQLiteConnectionPool.Shared.GetConnection(
                           new SQLiteConnectionString("sample.db", false));
    return connection;
}

private void Button_Click_1(object sender, RoutedEventArgs e)
{
    SQLiteConnection con = getConnection();
    con.BeginTransaction();
    {
        try
        {
            var command = new SQLiteCommand(con) {
                CommandText =
                    @"create table konysyncMETAINFO (
                        id bigint not null,
                        versionnumber int,
                        lastserversynccontext nvarchar(1000),
                        filtervalue nvarchar(1000),
                        replaysequencenumber integer,
                        lastgeneratedid integer,
                        scopename nvarchar(100),
                        primary key (id))"
            };
            var xyz = (double)command.ExecuteNonQuery();

            var command2 = new SQLiteCommand(con) {
                CommandText =
                    @"insert into konysyncMETAINFO
                        (id,scopename,versionnumber,lastserversynccontext,
                         replaysequencenumber,lastgeneratedid)
                      values ('1','testscope','0','','0','-1')"
            };
            var xyz2 = (double)command2.ExecuteNonQuery();

            var command3 = new SQLiteCommand(con) {
                CommandText =
                    @"insert into konysyncMETAINFO
                        (id,scopename,versionnumber,lastserversynccontext,
                         replaysequencenumber,lastgeneratedid)
                      values ('2','testscope2','0','','0','-1')"
            };
            var xyz3 = (double)command3.ExecuteNonQuery();
            con.Commit();
        }
        catch (Exception ex)
        {
            con.Rollback();
        }
    }
}

private void Button_Click_2(object sender, RoutedEventArgs e)
{
    SQLiteConnection con = getConnection();
    con.BeginTransaction();
    {
        try
        {
            var command = new SQLiteCommand(con) {
                CommandText =
                    @"Update konysyncMETAINFO
                      set lastgeneratedid='4'
                      WHERE scopename = 'testscope'"
            };
            var xyz = (double)command.ExecuteNonQuery();

            //var command2 = new SQLiteCommand(con) { CommandText = "insert into konysyncMETAINFO (id,scopename,versionnumber,lastserversynccontext,replaysequencenumber,lastgeneratedid) values ('3','testscope3','0','','0','-1')" };
            //var xyz2 = (double)command2.ExecuteNonQuery();

            var command3 = new SQLiteCommand(con) {
                CommandText =
                    @"Update konysyncMETAINFO 
                      set lastgeneratedid='3'
                      WHERE scopename = 'testscope'"
            };
            var xyz3 = (double)command3.ExecuteNonQuery();
            con.Commit();
        }
        catch (Exception ex)
        {
            con.Rollback();
        }
    }
}

回答1:


You've probably stumbled across the same bug in sqlite-net that I have. I've created a fix which has already been pulled back into the main fork but there hasn't been a new release on NuGet since then. You could download the latest sources directly and check if it fixes your problem.




回答2:


Adding this code right after opening the database will solve the problem ( both when sideloaded as well when the app gets downloaded through store)

verifySQLResult(SQLite3.Execute(_db, "PRAGMA temp_store = memory;", 0, 0, 0));

source:

https://github.com/praeclarum/sqlite-net/issues/78



来源:https://stackoverflow.com/questions/13705341/multiple-update-statements-throw-cannot-open

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