id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
28643	Complete the ORM Function Library	Matthew Pava	JunyiJ	"I was surprised to learn that we didn't have a StrIndex function until version 2, and yet we had Substr since at least version 1.8.  I wonder how users were using Substr without also finding a use for StrIndex this whole time.  Anyway, since we seem to be adding these functions one at a time, why don't we work on trying to get the built-ins implemented in one sweep instead?

We may even want to split the documentation page (https://docs.djangoproject.com/en/dev/ref/models/database-functions/) into further categories with String functions and Numeric functions.

This is just a sample checklist, with corresponding attributes to which backend has them available.

||||||||||||||||= **Comparison** =||
||**Django**||**SQL**||**Description**||**PostgreSQL**||**Oracle**||**MySQL**||**SQLite**||**PR**||
||{{{NullIf}}}||{{{NULLIF}}}||Returns {{{NULL}}} if the first argument equals the second.||‎✔||‎✔||‎✔||‎✔||[https://github.com/django/django/pull/9543 9543]||
||||||||||||||||= **Math** =||
||**Django**||**SQL**||**Description**||**PostgreSQL**||**Oracle**||**MySQL**||**SQLite**||**PR**||
||{{{Abs}}}||{{{ABS}}}||Returns the absolute value.||‎✔||‎✔||‎✔||‎✔||[https://github.com/django/django/pull/9622 9622]||
||{{{ACos}}}||{{{ACOS}}}||Returns the arccosine.||‎✔||‎✔||‎✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]||
||{{{ASin}}}||{{{ASIN}}}||Returns the arcsine.||‎✔||‎✔||‎✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]||
||{{{ATan}}}||{{{ATAN}}}||Returns the arctangent.||‎✔||‎✔||‎✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]||
||{{{ATan2}}}||{{{ATAN2}}}||Returns the arctangent of the two variables passed to it.||‎✔||‎✔||‎✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]||
||{{{Ceil}}}||{{{CEILING}}}||Returns the smallest integer value that is not less than a numeric expression||‎✔||{{{CEIL}}}||‎✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]||
||{{{Cos}}}||{{{COS}}}||Returns the cosine expressed in radians.||‎✔||‎✔||‎✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]||
||{{{Cot}}}||{{{COT}}}||Returns the cotangent.||‎✔||‎✔**^5^**||‎✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]||
||{{{Degrees}}}||{{{DEGREES}}}||Returns a numeric expression converted from radians to degrees.||‎✔||‎✔||‎✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]||
||{{{Exp}}}||{{{EXP}}}||Returns the base of the natural logarithm (e) raised to the power of a numeric expression.||‎✔||‎✔||‎✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]||
||{{{Floor}}}||{{{FLOOR}}}||Returns the largest integer value that is not greater than a numeric expression.||‎✔||‎✔||‎✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]||
||{{{Ln}}}||{{{LN}}}||Returns the natural logarithm of a numeric expression.||‎✔||‎✔||‎✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]||
||{{{Log}}}||{{{LOG(B, X)}}}||Returns the logarithm of a numeric expression.||‎✔||‎✔||‎✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]||
||{{{Mod}}}||{{{MOD}}}||Returns the remainder of one expression by diving by another expression.||‎✔||‎✔||‎✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]||
||{{{Pi}}}||{{{PI}}}||Returns the value of π||‎✔||✔**^4^**||‎✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]||
||{{{Power}}}||{{{POWER}}}||Returns the value of one expression raised to the power of another expression||‎✔||‎✔||‎✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]||
||{{{Radians}}}||{{{RADIANS}}}||Returns the value of an expression converted from degrees to radians.||‎✔||‎✔||‎✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]||
||{{{Round}}}||{{{ROUND}}}||Returns a numeric expression rounded to an integer.\\Can be used to round an expression to a number of decimal points||‎✔||‎✔||‎✔||‎✔||[https://github.com/django/django/pull/9622 9622]||
||{{{Sin}}}||{{{SIN}}}||Returns the sine given in radians.||‎✔||‎✔||‎✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]||
||{{{Sqrt}}}||{{{SQRT}}}||Returns the square root.||‎✔||‎✔||‎✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]||
||{{{Tan}}}||{{{TAN}}}||Returns the tangent expressed in radians.||‎✔||‎✔||‎✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]||
||||||||||||||||= **Text** =||
||**Django**||**SQL**||**Description**||**PostgreSQL**||**Oracle**||**MySQL**||**SQLite**||**PR**||
||{{{Ord}}}||{{{ASCII}}}||Returns numeric value of left-most character. (Equivalent to {{{ord()}}} in Python.)||‎✔||‎✔||‎✔||{{{UNICODE}}}||~~9583~~||
||{{{Chr}}}||{{{CHR}}}||Character with the given code||‎✔||‎✔||{{{CHAR}}}||{{{CHAR}}}||~~9583~~||
||{{{Left}}}||{{{LEFT}}}||Returns the leftmost number of characters as specified||‎✔||✔**^2, 6^**||‎✔||✔**^2^**||~~9583~~||
||{{{LPad}}}||{{{LPAD}}}||Returns the string argument, left-padded with the specified string||‎✔||‎✔||‎✔||✔**^1^**||~~9798~~||
||{{{LTrim}}}||{{{LTRIM}}}||Removes leading spaces||‎✔||‎✔||‎✔||‎✔||~~9220~~||
||{{{MD5}}}||{{{MD5}}}||Calculates the MD5 hash of string, returning the result in hexadecimal||‎✔||-||-||✔**^1^**||-||
||{{{Repeat}}}||{{{REPEAT}}}||Repeats a string the specified number of times||‎✔||✔**^3^**||‎✔||✔**^1^**||~~9808~~||
||{{{Replace}}}||{{{REPLACE}}}||Replaces occurrences of a specified string||‎✔||‎✔**^6^**||‎✔||‎✔||~~9539~~||
||{{{Reverse}}}||{{{REVERSE}}}||Reverse the characters in a string||‎✔||-||‎✔||✔**^1^**||-||
||{{{Right}}}||{{{RIGHT}}}||Returns the specified rightmost number of characters||‎✔||✔**^2^**||‎✔||✔**^2^**||~~9583~~||
||{{{RPad}}}||{{{RPAD}}}||Appends string the specified number of times||‎✔||‎✔**^6^**|||‎✔||✔**^1^**||~~9798~~||
||{{{RTrim}}}||{{{RTRIM}}}||Removes trailing spaces||‎✔||‎✔||‎✔||‎✔||~~9220~~||
||{{{Trim}}}||{{{TRIM}}}||Removes leading and trailing spaces||‎✔||‎✔||‎✔||‎✔||~~9220~~||

- **^1^** Function can be easily supported on SQLite with a [https://docs.python.org/3/library/sqlite3.html#sqlite3.Connection.create_function user defined function].
- **^2^** Behaviour can be emulated by using {{{SUBSTR}}}.
- **^3^** Behaviour can be emulated by using {{{LENGTH}}} and {{{RPAD}}}.
- **^4^** Behaviour can be emulated by directly substituting constant {{{math.pi}}}.
- **^5^** Behaviour can be emulated by using {{{1 / TAN(X)}}}.
- **^6^** Doesn't work properly with multibyte characters sets on Oracle."	New feature	assigned	Database layer (models, ORM)	dev	Normal			josh.smeaton@… Mariusz Felisiak Shai Berger Adam Johnson Thomas Lagae	Accepted	1	0	0	0	0	0