I needed to create a query that did a case insensitive search using the LIKE command in MySQL and I quickly realised that in order to do this I would need to alter both the parameter and the table data to be the same case. This can be done by using the MySQL UPPER() command on the table data and the strtoupper() PHP function on the input data.
When Google looks at a page it takes a snapshot of that page and uses this to match against the query a user entered. To view these cached pages run a Google search and look at the Cached link next to the green URL text of the result. When you view the cached page Google will also give you a date that the page was last cached on. This can be used as a metric of your sites importance as the more often the site is cached, the more favourable Google views your page.
If you have a table of incremental values it can be hard to find out which ones are missing. The only solution might be to write a script to get all the data from the database and see which ones are missing. However, there is a way of doing this without using a script.
Using a standard select query like this:
MySQL uses the datatype TINYINT to store boolean values. MySQL stores the value as TINYINT(1) which is the same as a bit so the value is either 0 (false) or 1 (true). Using boolean fields can be very useful, but it can be costly in processing as to change the value you have to query the database, find out the value of the field and then act accordingly.
Here is a simple MySQL query that can be used to toggle the value already present in the TINYINT field without having to do any pre-querying.