On Wed, 2019-05-22 at 14:24 -0400, Reid Thompson wrote: > On Wed, 2019-05-22 at 19:05 +0100, Simon Slavin wrote: > > [EXTERNAL SOURCE] > > > > > > > > On 22 May 2019, at 6:51pm, [email protected] wrote: > > > > > Please add a note to the omitted page that many basic math functions are > > > NOT supported. (sqrt,mod,power,stdev,etc.) > > > > Which ones should the documentation mention ? Can you find us a > > specification of SQL which includes that these functions ? I'm not talking > > about a SQL engine you can use, but one of the SQL > > standards which mentions them, so we know what SQLite leaves out. > > > > Compare SQLite with PostgreSQL: > > > > < > > > https://urldefense.proofpoint.com/v2/url?u=https-3A__www.postgresql.org_docs_current_functions-2Dmath.html&d=DwIGaQ&c=w8fEmIi-B5lsC0MnOiGTloUx5YmN70-3jVCmqqbXNxM&r=4r1gVE34nFB7YgioINuzq1cdGrlIBszDh26sKYP7ux8&m=jbjQXvGZh8bReMAfosQNap-8S64F4Q3WwjrDjOA9gGM&s=F9oXfi9o0vpUEQ6Qv_pxcKMHwuLHHbrqTRyq_uqq7_8&e= > > > > PostgreSQL lacks sqrt (though you can do it with power() or with '|/') and > > stdev (which you can't do). Both SQLite and PostgreSQL do modulo, using > > the '%' operator. > > _______________________________________________ > > > the referenced postgresql page lists sqrt in Mathematical Functions > sqrt(dp or numeric) (same as input) square root sqrt(2.0) > 1.4142135623731 > > >
additionally as info, https://www.postgresql.org/docs/9.1/functions-aggregate.html lists several stddev variants in Table 9-44. Aggregate Functions for Statistics ala [local:/home/rthompso/var]:5432 lite@lite=# select stddev(column1) from (select * from (values (10),(10),(100),(10)) as points) as foo; stddev --------------------- 45.0000000000000000 (1 row) [local:/home/rthompso/var]:5432 lite@lite=# select stddev_pop(column1) from (select * from (values (10),(10),(100),(10)) as points) as foo; stddev_pop --------------------- 38.9711431702997391 (1 row) [local:/home/rthompso/var]:5432 lite@lite=# select stddev_samp(column1) from (select * from (values (10),(10),(100),(10)) as points) as foo; stddev_samp --------------------- 45.0000000000000000 (1 row) _______________________________________________ sqlite-users mailing list [email protected] http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
