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Written with Claude
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As you may notice, this page and pretty much the entire website were obviously created with the help of AI. I wonder how you could tell? Was it a big "Written With Claude" badge on every page? I moved it to the top now (with the help of AI of course) to make it even more obvious. There are a few blogposts that were written by me manually, the old-fashioned way, I hope there will be more in the future, and those have a similar "Human Written" badge. This project (not the website), on the other hand, is a very, very different story. It took me more than two years of painstaking and unpaid work in my own free time. A story that, hopefully, I will tell someday. But meanwhile, what would you like me to do? To create a complex documentation website with a bunch of highly technical articles with the help of AI and fake it, to give you an illusion that I also did that manually? Like the half of itnernet is doing at this point? How does that makes any sense? Is that even fair to you? Or maybe to create this website manually, the old-fashioned way, just for you? While working a paid job for a salary, most of you wouldn't even get up in the morning. Would you like me to sing you a song while we're at it? For your personal entertainment? Seriously, get a grip. Do you find this information less valuable because of the way this website was created? I give my best to fix it to keep the information as accurate as possible, and I think it is very accurate at this point. If you find some mistakes, inaccurancies or problems, there is a comment section at the bottom of every page, which I also made with the help of the AI. And I woould very much appreciate if you leave your feedback there. Look, I'm just a guy who likes SQL, that's all. If you don't approve of how this website was constructed and the use of AI tools, I suggest closing this page and never wever coming back. And good riddance. And I would ban your access if I could know how. Thank you for your attention to this matter.

DEFINE_PARAM

Also known as

define_param (with or without @ prefix)

Define HTTP parameters that are not bound to the PostgreSQL command. These virtual parameters exist in the HTTP request (query string or JSON body) but do not correspond to any $N positional parameter in the SQL query.

This is useful for SQL file endpoints where you need HTTP parameters for:

  • Custom parameter placeholders — parameters that feed into annotation placeholders like {format} without being part of the SQL
  • Claim mapping — auto-filling parameters from authenticated user claims without referencing them in the query
  • HTTP request matching — parameters that affect endpoint behavior without participating in the database query

Syntax

code
@define_param name
@define_param name type
  • name — the HTTP parameter name
  • type — optional PostgreSQL type (default: text)

Custom Parameter Placeholders

Pass HTTP parameters that control endpoint behavior without referencing them in SQL:

sql
sql
-- sql/users_report.sql
-- @define_param format text
-- @table_format = {format}
-- @param $1 department_id
select id, name, email from users where department_id = $1;

GET /api/users-report?department_id=5&format=html_table

The format parameter feeds into the @table_format annotation via the {format} placeholder, selecting the output format (JSON, HTML table, Excel, etc.) without being part of the SQL query. Without @define_param, there would be no format parameter in the endpoint — the {format} placeholder would have nothing to resolve.

Claim Mapping

Auto-fill a parameter from the authenticated user's claims without including it in the SQL query:

sql
sql
-- sql/user_dashboard.sql
-- @authorize
-- @user_parameters
-- @define_param _user_id
select * from user_dashboard_data;

Here _user_id is created as a virtual parameter that maps to the name_identifier claim (via standard User Parameters claim mapping). The authenticated user's ID is injected automatically — but unlike @param, this parameter doesn't correspond to any $N in the SQL. The query itself doesn't filter by user — the virtual parameter exists solely for the claim mapping mechanism.

This is different from using @param with @user_parameters:

sql
sql
-- This uses @param — $1 IS in the SQL query
-- @authorize
-- @user_parameters
-- @param $1 _user_id
select * from orders where user_id = $1;

Use @define_param when the parameter shouldn't appear in the SQL at all. Use @param when you need the value both as a claim-mapped parameter and as a query parameter.

Default Type

If no type is specified, the parameter defaults to text:

sql
sql
-- These are equivalent:
-- @define_param _user_id
-- @define_param _user_id text

Specify a type when needed:

sql
sql
-- @define_param _user_id integer

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