SQL statement not filtering rows

Question

The following code passes this row. The last column is named toscode . I am trying to weed out rows whose toscolumn contains "W1" anywhere in the name. No columns are set up as an index. Doesn't work.

I read that the $ (escape) in front of W1 is to prevent SQL injection. Not sure what the % do, but it might have to do with indexes which is maybe why it doesn't work.

| SPX    |   0 |    8.3 |    8.7 | 2017-03-24 |               0 |   30 | PUT |   2400 | SPXW170324C02400000 | .SPXW1703242400 |

MySqlCommand cmd = conn.CreateCommand();
cmd.Parameters.AddWithValue("@symbol", symbol);
cmd.CommandText = @"select * 
                    from contractdetails 
                    where symbol = @symbol 
                       && toscode NOT LIKE '%$W1%'
                       && Type = 'PUT' 
                       && oBid > .09 
                       && not ITM  
                       && Days > 10 
                       && Days < 120 
                    order by Days asc";

Answer 1

your LIKE clause should be:

toscode NOT LIKE '%W1%'

remove the '$' -it doesnt belong or have any meaning in a LIKE clause. You would only have to worry about SQL injection if it was user provided input, which in your example is not the case.

the '%' character is a wildcard, so anything could be before or after 'W1' in your search