select « sql « C Q&A

1. Is there a performance difference between select * from tablename and select column1, column2 from tablename?    stackoverflow.com

Possible Duplicates:
Select * vs Specifying Column Names
Which is faster/best? SELECT * or SELECT column1, colum2, column3, etc.

2. Detecting no results in adodb select query    stackoverflow.com

I'm using ADODB connection in C. The code works more or less fine but I'm getting errors when there is no result for my query and I try to read it. ...

3. Why Select 77C works and not C77 in Sql    stackoverflow.com

If I write select 77C the output is

C
77

select C77