SQL查询UPDATE不能正常工作

Question

I have a simple asp.net website and a simple database.

The database has a table Users with this structure

Now I have been trying to execute this SQL command

UPDATE [Users] 
SET [UserName] = 'Teazst22',
    [Password] = 'Tesst',
    [Email] = 'Test@gmail.com',
    [FirstName] = 'Test12',
    [LastName] = 'Work1',
    [BirthDate] = '30/1/1920' 
WHERE [Email] = 'Test@gmail.com'

Command is executed from my C# code:

    public static void ChangeTable(string strSql, string FileName)
{
    try
    {
        OleDbConnection c = MakeConnection(FileName);
        OleDbCommand comm = new OleDbCommand();
        comm.CommandText = strSql;
        comm.Connection = c;
        comm.ExecuteNonQuery();
        c.Close();
        System.Diagnostics.Debug.WriteLine("SQL COMMAND Executed");
    }
    catch (Exception e)
    {
        System.Diagnostics.Debug.WriteLine(e.ToString());
    }
}

}

public static OleDbConnection MakeConnection(string dbFile)
{
    OleDbConnection c = new OleDbConnection();

    if (dbFile.ToLower().Contains(".accdb"))
        // MS Access >=2007
        c.ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0; Data Source=" + HttpContext.Current.Server.MapPath("~/App_Data/" + dbFile);
    else
        // MS Access 2003
        c.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0; Data Source=" + HttpContext.Current.Server.MapPath("~/App_Data/" + dbFile);

    c.Open();
    return c;

}

 private String Email = "";
private String Username = "";
protected void Page_Load(object sender, EventArgs e)
{
    if ((Session["IsAdmin"] != null && !(bool)Session["IsAdmin"]) || Session["IsAdmin"] == null)
        Response.Redirect("Default.aspx");

   String StrSql = "Select * from [Users] where Email='{0}'";
    StrSql = String.Format(StrSql, Request.QueryString.Get("Em"));
   DataTable Dt=  MyDbase.SelectFromTable(StrSql, "Db.ACCDB");
    if (Dt.Rows.Count == 1)
    {
        USTXT.Text = Dt.Rows[0]["UserName"].ToString();
        PTXT.Text = Dt.Rows[0]["Password"].ToString();
        EmailTXT.Text = Dt.Rows[0]["Email"].ToString();
        FirstNTXT.Text = Dt.Rows[0]["FirstName"].ToString();
        LastNTXT.Text = Dt.Rows[0]["LastName"].ToString();
        BirthDTXT.Text = Dt.Rows[0]["BirthDate"].ToString();
        Email = EmailTXT.Text;
        Username = USTXT.Text;
    }

}
protected void SaveBTN_Click(object sender, EventArgs e)
{
    String StrSql = "Update [Users] Set [UserName]='{0}',[Password]='{1}',[Email]='{2}',[FirstName]='{3}',[LastName]='{4}',[BirthDate]='{5}' WHERE [Email]='{6}'";
    StrSql = String.Format(StrSql, USTXT.Text, PTXT.Text, EmailTXT.Text, FirstNTXT.Text, LastNTXT.Text, BirthDTXT.Text , Email);

    MyDbase.ChangeTable(StrSql,"Db.ACCDB");
    Response.Redirect("Admin.aspx");
}

When executing the code no errors are shown, but when I check the database, nothing has changed... quite simply, the command is not working.

PS: the database that I'm using is Microsoft Access 2007

Answer 1

Please make sure that the mdb file you are observing is in "Data Directory" folder. you might be checking wrong file. Also check the property of that mdb file, whether its last modified time is approx to the time you performed database operation.

Answer 2

Simply this code put inside the try catch statement and try to catch your error .. as i seem definitely you can find the problem in this way

try 
{
    OleDbConnection c = MakeConnection(Database name);
    OleDbCommand comm = new OleDbCommand();
    comm.CommandText = SqlStr;
    comm.Connection = c;
    comm.ExecuteNonQuery();
    c.Close();
}
catch  (Exception e)
{
    Console.WriteLine(e.Message.ToString());
}

Answer 3

It might be that you have a db collation which is case sensitive and you are comparing uppercase letter to lowercase letter? https://msdn.microsoft.com/en-us/library/ms144250(v=sql.105).aspx

where test = Test would not gives any results if it's case sensitive