Difference between ExecuteScalar() and ExecuteNonQuery()

Question

The title may look like usual. But I have worth question.

I referred this link for difference between ExecuteScalar() and ExecuteNonQuery().

But in that they mentioned as, ExecuteScalar() work only with non-action queries.

Is it true?

Many understood ExecuteScalar() wrongly.

Have you guys ever tried the below code?

SqlConnection con = new SqlConnection("Data Source=SCI-DT-13; Initial Catalog=exercise; Integrated Security=true");
con.Open();
SqlCommand cmd = new SqlCommand("Insert into empdetails values('" + t_empid.Text + "','" + t_empname.Text + "','" + t_empdesig.Text + "')", con);
cmd.ExecuteScalar();

I am sure that this code will work fine and the row will be inserted into the table.

My question is, if we can perform action queries in ExecuteScalar() then why we need ExecuteNonQuery()?

Answer 1

You're right that ExecuteScalar will return null for action queries.

One reason to use ExecuteNonQuery is that it returns the number of rows affected.

I don't think you should consider that the article you linked to be an authoritative source - better to refer to what MSDN says.

Answer 2

ExexuteScalar - It returns only one value.
ExecuteNonQuery- It does only the DML operations like INSERT,UPDATE,DELETE