How do I count the number of rows returned in my SQLite reader in C#?

Question

I\'m working in Microsoft Visual C# 2008 Express and with SQLite.

I\'m querying my database with something like this:

SQLiteCommand cmd = new SQLiteC         


        

Answer 1

Normally i would do

select count(1) from myTable where word = '" + word + "';";

to get the result as fast as possible. In the case where id is an int then it won't make much difference. If it was something a bit bigger like a string type then you'll notice a difference over a large dataset.

Reasoning about it count(1) will include the null rows. But i'm prepared to be corrected if i'm wrong about that.

Answer 2

SQLiteCommand cmd = new SQLiteCommand(conn);
cmd.CommandText = "select id from myTable where word = '" + word + "';";
SQLiteDataReader reader = cmd.ExecuteReader();

while (reader.Read())
       {
          total_rows_in_resultset++;
       }

Answer 3

If you are only loading an id column from the database, would it not be easier to simply load into a List<string> and then work from there in memory?

Answer 4

Surely a better way to get a row count would be something like this:-

 SQLiteDataReader reader = SendReturnSQLCommand(dbConnection, "SELECT COUNT(*) AS rec_count FROM table WHERE field = 'some_value';");
      if (reader.HasRows) {
         reader.Read();
        int  count = Convert.ToInt32(reader["rec_count"].ToString());

...

    }

That way you don't have to iterate over the rows

Answer 5

but I really need to know the count before

Why is that ? this is usually not necessary, if you use adequate in-memory data structures (Dataset, List...). There is probably a way to do what you want that doesn't require to count the rows beforehand.