c#，使用 visual studio 2012，能够保存到数据库但不能更新

Question

下面是我写的代码，请大家检查一下，说说哪里不对。我在此处 post 编辑了插入和更新代码。

我是从 youtube 上学到的，所以我不知道关于数据库的每一个细节，所以请post用像我这样的业余爱好者能理解的语言

 public void bsave_Click(object sender, RoutedEventArgs e)
 {
        SQLiteConnection sqliyeCon = new SQLiteConnection(dbConnectionString);
        //open connection to database
        try
        {
            sqliyeCon.Open();
            string Query = "insert into employeeinfo (name,surname,age) values('" + this.name.Text + "', '" + this.surname.Text + "' , '" + this.age.Text + "')";
            SQLiteCommand createCommand = new SQLiteCommand(Query, sqliyeCon);
            createCommand.ExecuteNonQuery();
            MessageBox.Show("Data is saved succesfully");
            sqliyeCon.Close();
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }
 }

 private void bup_Click(object sender, RoutedEventArgs e)
 {
        SQLiteConnection sqliyeCon = new SQLiteConnection(dbConnectionString);
        //open connection to database
        try
        {
            sqliyeCon.Open();
            string Query = "update employeeinfo set eid='" + this.eid.Text + "' , name ='" + this.name.Text + "',surname='" + this.surname.Text + "', age='" + this.age.Text + "' where eid=eid='" + this.eid.Text + "' ";
            SQLiteCommand createCommand = new SQLiteCommand(Query, sqliyeCon);
            createCommand.ExecuteNonQuery();
            MessageBox.Show("Updated");
            sqliyeCon.Close();
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }
    }
}

Answer 1

"' where eid=eid='" 应该是 "' where eid='"

string Query = "update employeeinfo set eid='" + this.eid.Text + "' , name ='" + this.name.Text + "',surname='" + this.surname.Text + "', age='" + this.age.Text + "' where eid='" + this.eid.Text + "' ";

c#，使用 visual studio 2012，能够保存到数据库但不能更新

c#, using visual studio 2012 ,able to save to database but cannot update

c#

system.data.sqlite

insert-update

sql-update