#28643: Complete the ORM Function Library -------------------------------------+------------------------------------- Reporter: Matthew Pava | Owner: JunyiJ Type: New feature | Status: assigned Component: Database layer | Version: master (models, ORM) | Severity: Normal | Resolution: Keywords: | Triage Stage: Accepted Has patch: 1 | Needs documentation: 0 Needs tests: 0 | Patch needs improvement: 0 Easy pickings: 0 | UI/UX: 0 -------------------------------------+------------------------------------- Description changed by Nick Pope:
Old description: > 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** =|| > ||**Name**||**Description**||**PostgreSQL**||**Oracle**||**MySQL**||**SQLite**||**PR**|| > ||NULLIF()||Returns NULL if the first argument equals the > second.||X||X||X||X||[https://github.com/django/django/pull/9543 9543]|| > ||||||||||||||= **Math** =|| > ||**Name**||**Description**||**PostgreSQL**||**Oracle**||**MySQL**||**SQLite**||**PR**|| > ||ABS()||Returns the absolute > value.||X||X||X||X||[https://github.com/django/django/pull/9577 9577]|| > ||ACOS()||Returns the arccosine.||X||X||X||-||-|| > ||ASIN()||Returns the arcsine.||X||X||X||-||-|| > ||ATAN()||Returns the arctangent.||X||X||X||-||-|| > ||ATAN2()||Returns the arctangent of the two variables passed to > it.||X||X||X||-||-|| > ||CEILING()||Returns the smallest integer value that is not less than a > numeric expression||X||as CEIL()||X||-||-|| > ||COS()||Returns the cosine expressed in radians.||X||X||X||-||-|| > ||COT()||Returns the cotangent.||X||X||X||-||-|| > ||DEGREES()||Returns a numeric expression converted from radians to > degrees.||X||X||X||-||-|| > ||EXP()||Returns the base of the natural logarithm (e) raised to the > power of a numeric expression.||X||X||X||-||-|| > ||FLOOR()||Returns the largest integer value that is not greater than a > numeric expression.||X||X||X||-||-|| > ||LOG()||Returns the natural logarithm of a numeric > expression.||X||X||X||-||-|| > ||MOD()||Returns the remainder of one expression by diving by another > expression.||X||X||X||-||-|| > ||PI()||Returns the value of pi||X||-||X||-||-|| > ||POWER()||Returns the value of one expression raised to the power of > another expression||X||X||X||-||-|| > ||RADIANS()||Returns the value of an expression converted from degrees to > radians.||X||X||X||-||-|| > ||ROUND()||Returns a numeric expression rounded to an integer.\\Can be > used to round an expression to a number of decimal > points||X||X||X||X||-|| > ||SIN()||Returns the sine given in radians.||X||X||X||-||-|| > ||SQRT()||Returns the square root.||X||X||X||-||-|| > ||TAN()||Returns the tangent expressed in radians.||X||X||X||-||-|| > ||||||||||||||= **Text** =|| > ||**Name**||**Description**||**PostgreSQL**||**Oracle**||**MySQL**||**SQLite**||**PR**|| > ||ASCII() (In Python, it is ord())||Returns numeric value of left-most > character||X||X||X||as > UNICODE()||[https://github.com/django/django/pull/9583 9583]|| > ||CHR()||Character with the given code||X||X||as CHAR()||as > CHAR()||[https://github.com/django/django/pull/9583 9583]|| > ||LEFT()||Returns the leftmost number of characters as specified||X||as > SUBSTR()||X||as SUBSTR()||[https://github.com/django/django/pull/9583 > 9583]|| > ||LPAD()||Returns the string argument, left-padded with the specified > string||X||X||X||-||-|| > ||LTRIM()||Removes leading > spaces||X||X||X||X||[https://github.com/django/django/pull/9220 9220]|| > ||MD5()||Calculates the MD5 hash of string, returning the result in > hexadecimal||X||-||-||-||-|| > ||REPEAT()||Repeats a string the specified number of > times||X||-||X||-||-|| > ||REPLACE()||Replaces occurrences of a specified > string||X||X||X||X||[https://github.com/django/django/pull/9539 9539]|| > ||REVERSE()||Reverse the characters in a string||X||-||X||-||-|| > ||RIGHT()||Returns the specified rightmost number of characters||X||as > SUBSTR()||X||as SUBSTR()||[https://github.com/django/django/pull/9583 > 9583]|| > ||RPAD()||Appends string the specified number of times||X||X||X||-||-|| > ||RTRIM()||Removes trailing > spaces||X||X||X||X||[https://github.com/django/django/pull/9220 9220]|| > ||TRIM()||Removes leading and trailing > spaces||X||X||X||X||[https://github.com/django/django/pull/9220 9220]|| New description: 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** =|| ||**Name**||**Description**||**PostgreSQL**||**Oracle**||**MySQL**||**SQLite**||**PR**|| ||{{{NULLIF}}}||Returns {{{NULL}}} if the first argument equals the second.||✔||✔||✔||✔||[https://github.com/django/django/pull/9543 9543]|| ||||||||||||||= **Math** =|| ||**Name**||**Description**||**PostgreSQL**||**Oracle**||**MySQL**||**SQLite**||**PR**|| ||{{{ABS}}}||Returns the absolute value.||✔||✔||✔||✔||[https://github.com/django/django/pull/9577 9577], [https://github.com/django/django/pull/9622 9622]|| ||{{{ACOS}}}||Returns the arccosine.||✔||✔||✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]|| ||{{{ASIN}}}||Returns the arcsine.||✔||✔||✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]|| ||{{{ATAN}}}||Returns the arctangent.||✔||✔||✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]|| ||{{{ATAN2}}}||Returns the arctangent of the two variables passed to it.||✔||✔||✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]|| ||{{{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}}}||Returns the cosine expressed in radians.||✔||✔||✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]|| ||{{{COT}}}||Returns the cotangent.||✔||✔||✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]|| ||{{{DEGREES}}}||Returns a numeric expression converted from radians to degrees.||✔||✔||✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]|| ||{{{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}}}||Returns the largest integer value that is not greater than a numeric expression.||✔||✔||✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]|| ||{{{LOG}}}||Returns the natural logarithm of a numeric expression.||✔||✔||✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]|| ||{{{MOD}}}||Returns the remainder of one expression by diving by another expression.||✔||✔||✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]|| ||{{{PI}}}||Returns the value of π||✔||-||✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]|| ||{{{POWER}}}||Returns the value of one expression raised to the power of another expression||✔||✔||✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]|| ||{{{RADIANS}}}||Returns the value of an expression converted from degrees to radians.||✔||✔||✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]|| ||{{{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}}}||Returns the sine given in radians.||✔||✔||✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]|| ||{{{SQRT}}}||Returns the square root.||✔||✔||✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]|| ||{{{TAN}}}||Returns the tangent expressed in radians.||✔||✔||✔||✔**^1^**||[https://github.com/django/django/pull/9622 9622]|| ||||||||||||||= **Text** =|| ||**Name**||**Description**||**PostgreSQL**||**Oracle**||**MySQL**||**SQLite**||**PR**|| ||{{{ASCII}}}||Returns numeric value of left-most character. (Equivalent to {{{ord()}}} in Python.)||✔||✔||✔||{{{UNICODE}}}||[https://github.com/django/django/pull/9583 9583]|| ||{{{CHR}}}||Character with the given code||✔||✔||{{{CHAR}}}||{{{CHAR}}}||[https://github.com/django/django/pull/9583 9583]|| ||{{{LEFT}}}||Returns the leftmost number of characters as specified||✔||✔**^2^**||✔||✔**^2^**||[https://github.com/django/django/pull/9583 9583]|| ||{{{LPAD}}}||Returns the string argument, left-padded with the specified string||✔||✔||✔||-||-|| ||{{{LTRIM}}}||Removes leading spaces||✔||✔||✔||✔||[https://github.com/django/django/pull/9220 9220]|| ||{{{MD5}}}||Calculates the MD5 hash of string, returning the result in hexadecimal||✔||-||-||✔**^1^**||-|| ||{{{REPEAT}}}||Repeats a string the specified number of times||✔||-||✔||-||-|| ||{{{REPLACE}}}||Replaces occurrences of a specified string||✔||✔||✔||✔||[https://github.com/django/django/pull/9539 9539] [[span(style=font-size:75%, (Merged))]]|| ||{{{REVERSE}}}||Reverse the characters in a string||✔||-||✔||✔**^1^**||-|| ||{{{RIGHT}}}||Returns the specified rightmost number of characters||✔||✔**^2^**||✔||✔**^2^**||[https://github.com/django/django/pull/9583 9583]|| ||{{{RPAD}}}||Appends string the specified number of times||✔||✔||✔||-||-|| ||{{{RTRIM}}}||Removes trailing spaces||✔||✔||✔||✔||[https://github.com/django/django/pull/9220 9220]|| ||{{{TRIM}}}||Removes leading and trailing spaces||✔||✔||✔||✔||[https://github.com/django/django/pull/9220 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}}}. -- -- Ticket URL: <https://code.djangoproject.com/ticket/28643#comment:32> Django <https://code.djangoproject.com/> The Web framework for perfectionists with deadlines. -- You received this message because you are subscribed to the Google Groups "Django updates" group. 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