Fixed #25912 --Added binary left/right shift operators to F expressions.

[anabelensc]

django-developers discussion

[charettes]

Try to keep docs line length below 80 characters.

[adamchainz]

I think adding this would be good to add for completion. I'd say it's slightly less surprising to implement the bit shifting with maths on Oracle rather than raising NotImplementedError, given that for other database functions such work arounds tend to get used.

[timgraham]

All right, absent other feedback, I guess we'll proceed with this. Patch needs to be targeted at Django 1.11 and updated per Adam's comments.

[atombrella]

https://docs.oracle.com/cd/E22583_01/DR/help/Bit_Binary_Functions.html#DALc02a_2726006080_257082 Oracle implements this with bitshift.

[timgraham]

I copied Oracle's implementation from BITAND but get ORA-00904: "BITSHIFT": invalid identifier. Not sure what could be wrong. \cc @felixxm

queries:
works:

UPDATE "EXPRESSIONS_NUMBER" SET "THE_INTEGER" =
 (BITAND("EXPRESSIONS_NUMBER"."THE_INTEGER",:arg0))
WHERE "EXPRESSIONS_NUMBER"."ID" = :arg

fails:

UPDATE "EXPRESSIONS_NUMBER" SET "THE_INTEGER" =
(BITSHIFT("EXPRESSIONS_NUMBER"."THE_INTEGER",:arg0))
WHERE "EXPRESSIONS_NUMBER"."ID" = :arg1

[timgraham]

The linked documentation seems to be for something called "Document Automation Language (DAL)". I guess this is different than what the Oracle database supports.

[From stackoverflow] (http://stackoverflow.com/questions/20085462/bit-shifting-with-and-operation-in-sql-select):

Oracle's PL/SQL has a BITAND() function. Shift-right is the same as integer division by a power of 2. Assuming X is an integer, X >> 27 is the same as X / 134217728.

I'll try this approach.

[timgraham]

Updated in #7770.

[felixxm]

To be honest I have never heard about DAL, but I think that we can not use it in SQL or PL/SQL.