SQLPage built-in functions

In addition to normal SQL functions supported by your database, SQLPage provides a few special functions to help you extract data from user requests.

These functions are special, because they are not executed inside your database, but by SQLPage itself before sending the query to your database. Thus, they require all the parameters to be known at the time the query is sent to your database. Function parameters cannot reference columns from the rest of your query. The only case when you can call a SQLPage function with a parameter that is not a constant is when it appears at the top level of a SELECT statement. For example, SELECT sqlpage.url_encode(url) FROM t is allowed because SQLPage can execute SELECT url FROM t and then apply the url_encode function to each value.

The sqlpage.header function

Introduced in SQLPage 0.7.2.

Reads a header with the given name from the request. Returns the value of the header as text, or NULL if the header is not present.


Log the User-Agent of the browser making the request in the database:

INSERT INTO user_agent_log (user_agent) VALUES (sqlpage.header('user-agent'));



The name of the HTTP header to read.