Question

In my c# application i am inserting data into sqlite database as below

String sqlExpr = "INSERT INTO item (id, typeid, ownerid, created, modifiedby, modified,active,imageuploaded,logouploaded,language_item) VALUES (@Id,@type_TypeId ,@db_currentUser,@dates,@db_id ,@modified,@active_status,@image,@logo,@language)";

using (SQLiteCommand _insertItem = new SQLiteCommand())
{
    _insertItem.CommandText = sqlExpr;
    _insertItem.Parameters.AddWithValue("@Id", Id);
    _insertItem.Parameters.AddWithValue("@type_TypeId", type.TypeId);
    _insertItem.Parameters.AddWithValue("@db_currentUser", db.currentUser.id);
    _insertItem.Parameters.AddWithValue("@dates", DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"));
    _insertItem.Parameters.AddWithValue("@db_id", db.currentUser.id);
    _insertItem.Parameters.AddWithValue("@modified", DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"));
    _insertItem.Parameters.AddWithValue("@active_status", active_status);
    _insertItem.Parameters.AddWithValue("@image", "false");
    _insertItem.Parameters.AddWithValue("@logo", "false");
    _insertItem.Parameters.AddWithValue("@language", language);
    rowsAffected = db.ExecuteNonQuerySQL(_insertItem);
}

And ExecuteNonQuery function as below

public int ExecuteNonQuerySQL(SQLiteCommand cmd)
{
    int ireturn = 0;
    if (conn.DataSource!="local")
        conn = new SQLiteConnection("data source=" + DataFile);
    if (conn.State != ConnectionState.Open)
        Open(DataFile);

    using (SQLiteTransaction dbtrans = conn.BeginTransaction())
    {
        cmd.Connection = conn;
        cmd.CommandType = CommandType.Text;
        ireturn = cmd.ExecuteNonQuery();
        dbtrans.Commit();
    }
    Close();
    return ireturn;
}

where i am getting error as database locked, please see below error message,

System.Data.SQLite.SQLiteException: The database file is locked
database is locked
at System.Data.SQLite.SQLite3.Step(SQLiteStatement stmt)
at System.Data.SQLite.SQLiteDataReader.NextResult()
at System.Data.SQLite.SQLiteDataReader..ctor(SQLiteCommand cmd, CommandBehavior behave)
at System.Data.SQLite.SQLiteCommand.ExecuteReader(CommandBehavior behavior)
at System.Data.SQLite.SQLiteCommand.ExecuteNonQuery()
at System.Data.SQLite.SQLiteTransaction.Commit()
at ThingzDB.ThingzDatabase.ExecuteNonQuerySQL(SQLiteCommand cmd)

Is something blocking in using statement…The code resides in different classes.
please help
thanx in advance

Answer 1

As a guess: from the last run of the program, which ended by termination, SQLite have left its lock file (or maybe you have another copy of the same program using this DB still hanging), and you naturally can’t open the DB.
Try to manually delete the lock file which is besides the db file.