OleDbCommand.ExecuteNonQuery()不更改保存在MS Access数据库 [英] OleDbCommand.ExecuteNonQuery() does not save changes in ms access database
问题描述
我有的.mdb
数据库和code是这样的:
I have .mdb
database, and code like this:
using (OleDbConnection connection = new OleDbConnection(myConnectionString))
{
using (OleDbCommand cmd = connection.CreateCommand())
{
cmd.CommandText = "UPDATE myTab SET col2 = @val1 WHERE col1 = @val2";
cmd.Parameters.AddWithValue("@val1", 0);
cmd.Parameters.AddWithValue("@val2", -1);
cmd.Connection.Open();
cmd.ExecuteNonQuery();
cmd.Connection.Close();
}
}
我得到的数据从数据库,改变它在我的GUI PROGRAMM,然后将其保存在数据库中。变化的扑救,但不是在分贝(我不知道在哪里),所以当我运行程序,更改数据,关闭程序,然后重新运行 - 更改均保持不变,但是当我打开数据库(而不是在PROGRAMM),有没有改变保存,并再次运行 - 所有的变化消失
。
PS:当我提交更改,然后运行程序几次,所有的变化消失得,后(3-4道)
I get data from db, change it in my gui programm, then save it in db. Changes saves, but not in db (I don't know where), so when I run program, change data, close program, then again run - changes remain, but when I open db (not in programm), there are no changes saved, and again run - all changes disappear.
PS: when I commit changes, then run program several times, all changes disappear too, after (3-4 runs)
推荐答案
当我们我们添加的.mdb
项目根VS,当改变结构,VS默认情况下删除的.mdb
文件中的debug文件夹,并更换新的文件;现在你可以改变这种defult:
When we we add .mdb
in project root in VS ,when change structure ,VS default delete .mdb
file in debug folder and replace new file; now you can change this defult :
1右键点击的.mdb
文件,并选择选项
1- right click .mdb
file and select option
2 - 集复制到输出目录
到不要复制
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