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.persist_uploaded_file function

Introduced in SQLPage 0.20.1.

Persists an uploaded file to the local filesystem, and returns its path. If the file input field is empty, the function returns NULL.

Example

User profile picture

upload_form.sql
select 'form' as component, 'persist_uploaded_file.sql' as action;
select 'file' as type, 'profile_picture' as name, 'Upload your profile picture' as label;
persist_uploaded_file.sql
update user
set profile_picture = sqlpage.persist_uploaded_file('profile_picture', 'profile_pictures', 'jpg,jpeg,png,gif,webp')
where id = (
    select user_id from session where session_id = sqlpage.cookie('session_id')
);

Parameters

file

Name of the form field containing the uploaded file. The current page must be referenced in the `action` property of a `form` component that contains a file input field.

destination_folder

Optional. Path to the folder where the file will be saved, relative to the web root (the root folder of your website files). By default, the file will be saved in the `uploads` folder.

allowed_extensions

Optional. Comma-separated list of allowed file extensions. By default: jpg,jpeg,png,gif,bmp,webp,pdf,txt,doc,docx,xls,xlsx,csv,mp3,mp4,wav,avi,mov. Changing this may be dangerous ! If you add "sql", "svg" or "html" to the list, an attacker could execute arbitrary SQL queries on your database, or impersonate other users.