Insert into SQL Server table using C#

Question

I am using the following code in order to insert some data into my SQL Server table. There isn't any error shown, but the table doesn't insert the values. What is wrong with it?

string sqlTxt1 = "INSERT INTO Users (ChatId , UserName) VALUES (@ChatId, @from)";

SqlCommand cmd1 = new SqlCommand(sqlTxt1, con);
cmd1.Parameters.AddWithValue("@ChatId", 12345);
cmd1.Parameters.AddWithValue("@from", "usrnm");

con.Open();
cmd1.ExecuteNonQuery();
//int recordsAffected =cmd1.ExecuteNonQuery();
con.Close();

As I put the code in a button and set the ChatId in the table as a primary key, I get an error when I click it twice, so I think the code is correct, but why the table doesn't get those values in the first click?

Unrelated to your problem but you should [avoid AddWithValue](https://www.dbdelta.com/addwithvalue-is-evil/). — Dan Guzman, Aug 02 '20 at 11:00
Ok, you already know the problem clicking twice and the primery key, but, what exactly should be the behaviour on the second click? Update the record if it already exists? Or insert a new one? — Felipe Oriani, Aug 09 '20 at 23:37
See https://stackoverflow.com/questions/23301582/how-do-i-to-insert-data-into-an-sql-table-using-c-sharp-as-well-as-implement-an/23301661 — Henrik Høyer, Feb 04 '21 at 09:44

score 0 · Answer 1 · answered Aug 02 '20 at 10:42

0

It should be string sqlTxt1 = "INSERT INTO Users (ChatId , UserName) VALUES (@ChatId, @from)";. You need to pass @from also.

You are inserting not updating the table. So when you click the second time, it tries to insert the record with the same primary key into the table again. You cannot insert the same value for the primary key in the table more than once, it will be a primary key violation. The primary key is always unique.

answered Aug 02 '20 at 10:42

Vivek Nuna

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I know that and updated the missed parameters, I meant I click twice to see if it considers that Error or not. It doesn't update the table in the first click too. – Javad-M Aug 02 '20 at 10:45
why should it update? It is insert command not update – Vivek Nuna Aug 02 '20 at 10:55
OK. It does not insert. – Javad-M Aug 02 '20 at 10:56
There isn't any Error. – Javad-M Aug 02 '20 at 10:58
Maybe something is wrong with my database settings? – Javad-M Aug 02 '20 at 11:02

Insert into SQL Server table using C#

1 Answers1