Parameters

prestd uses query string to apply filtering, sorting, paginating, and etc to api queries.

Filters

HTTP method GET

query string	Description
_page={set page number}	the api return is paged, this parameter sets which page you want
_page_size={number to return by pages}	delimits the number of records per page, default 10. Every time you specify a page size, you must include the page you are accessing.
?_select={field name 1},{fiel name 2}	Limit fields list on result - sql ansii standard
?_count={field name}	Count per field - * representation all fields
?_count_first=true	Query string _count returns a list, passing this parameter will return the first record as a non-list object, by default this parameter is set to false (return list non-object)
?_renderer=xml	Set API render syntax, supported: json (by default), xml
?_distinct=true	DISTINCT clause with SELECT
?_order={FIELD}	ORDER BY in sql query. For DESC order, use the prefix -. For multiple orders, the fields are separated by comma fieldname01,-fieldname02,fieldname03
?_groupby={FIELD}	GROUP BY in sql query, The grouper is more complicated, a topic has been created to describe how to use
?{FIELD NAME}={VALUE}	Filter by field, you can set as many query parameters as needed

Functions support

Used to perform data aggregation(grouping and selection)

name	Use in request
SUM	sum:field
AVG	avg:field
MAX	max:field
MIN	min:field
STDDEV	stddev:field
VARIANCE	variance:field

SELECT with function:

/{DATABASE}/{SCHEMA}/{TABLE}?_select=fieldname00,sum:fieldname01&_groupby=fieldname01

GROUP BY with function:

/{DATABASE}/{SCHEMA}/{TABLE}?_groupby=fieldname->>having:GROUPFUNC:FIELDNAME:CONDITION:VALUE-CONDITION
/{DATABASE}/{SCHEMA}/{TABLE}?_select=fieldname00,sum:fieldname01&_groupby=fieldname01->>having:sum:fieldname01:$gt:500

Operators Reference Guide

The following operators are used for filtering data in queries. Each operator defines a specific matching condition that determines which records are included in the result set.

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Operator	Description	Example Usage
$eq	Matches values that are equal to a specified value.	status=$eq.active
$gt	Matches values greater than a specified value.	age=$gt.25
$gte	Matches values greater than or equal to a specified value.	salary=$gte.50000
$lt	Matches values less than a specified value.	experience=$lt.5
$lte	Matches values less than or equal to a specified value.	rating=$lte.4.5
$ne	Matches values that are not equal to a specified value.	status=$ne.closed
$in	Matches any of the values specified in an array.	role=$in.admin,editor,viewer
$nin	Matches none of the values specified in an array.	department=$nin.hr,finance
$null	Matches if the field value is null.	remarks=$null
$notnull	Matches if the field value is not null.	remarks=$notnull
$true	Matches if the field value is true.	is_verified=$true
$nottrue	Matches if the field value is not true.	is_verified=$nottrue
$false	Matches if the field value is false.	is_active=$false
$notfalse	Matches if the field value is not false.	is_active=$notfalse
$like	Matches the entire string (case-sensitive).	name=$like.John%
$ilike	Matches the entire string, case-insensitive.	city=$ilike.mumbai%
$nlike	Excludes matches that cover the entire string.	email=$[e-mail]
$nilike	Excludes matches, case-insensitive.	email=$[e-mail]
$ltreelanc	Checks if left argument is an ancestor of right (or equal).	category_path=$ltreelanc.electronics
$ltreerdesc	Checks if left argument is a descendant of right (or equal).	category_path=$ltreerdesc.electronics.mobiles
$ltreematch	Checks if ltree matches lquery.	tags=$ltreematch.tech.*
$ltreematchtxt	Checks if ltree matches ltxtquery.	tags=$ltreematchtxt.smartphone & android

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Notes

• Comma (,) is used to separate multiple values in $in and $nin operators.

• Pattern matching operators like $like and $ilike support SQL wildcards (%, _).

• LTree operators ($ltreelanc, $ltreerdesc, etc.) are useful for hierarchical data filtering.