Passing parameters to a query [sql-rest-params]

Using values in a query condition, for example, or in a HAVING statement can be done "inline", by integrating the value in the query string itself:

console

POST /_sql?format=txt
{
  "query": "SELECT YEAR(release_date) AS year FROM library WHERE page_count > 300 AND author = 'Frank Herbert' GROUP BY year HAVING COUNT(*) > 0"
}

% TEST[setup:library]

or it can be done by extracting the values in a separate list of parameters and using question mark placeholders (?) in the query string:

console

POST /_sql?format=txt
{
  "query": "SELECT YEAR(release_date) AS year FROM library WHERE page_count > ? AND author = ? GROUP BY year HAVING COUNT(*) > ?",
  "params": [300, "Frank Herbert", 0]
}

% TEST[setup:library]

::::{important} The recommended way of passing values to a query is with question mark placeholders, to avoid any attempts of hacking or SQL injection. ::::