At first glance the logic seems OK to me.

I do have some trouble with the $sth->rows

To get the number of records returned of a select statement one should not rely on the rows function. For one it is not guaranteed to work on all databases and for second its use should be restricted to non-select statements.

From the DBI-docs:

rows
$rv = $sth->rows;

Returns the number of rows affected by the last row affecting command, or -1 if the number of rows is not known or not available.

Generally, you can only rely on a row count after a non-SELECT execute (for some specific operations like UPDATE and DELETE), or after fetching all the rows of a SELECT statement.

For SELECT statements, it is generally not possible to know how many rows will be returned except by fetching them all. Some drivers will return the number of rows the application has fetched so far, but others may return -1 until all rows have been fetched. So use of the rows method or $DBI::rows with SELECT statements is not recommended.

One alternative method to get a row count for a SELECT is to execute a ``SELECT COUNT(*) FROM ...'' SQL statement with the same ``...'' as your query and then fetch the row count from that.

Running a SELECT count(*) ... will work and is very fast.

Anyhow, if I understand your code correctly, you only expect one record anyhow (or none if the log-in failed). So why don't you check if the result of the SELECT count(*) ... is 1, in which case you retrieve the data to set the cookies, or in all other cases (no records or mulltiple records) you raise an error.

CountZero

"If you have four groups working on a compiler, you'll get a 4-pass compiler." - Conway's Law

In reply to Re^7: Premature end of script headers issue by CountZero
in thread Premature end of script headers issue by Anonymous Monk

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