Looking at the SQL queries run when user.has_perms(perms) is called, I see:
SELECT "auth_permission"."id",
"auth_permission"."name",
"auth_permission"."content_type_id",
"auth_permission"."codename",
"django_content_type"."id",
"django_content_type"."name",
"django_content_type"."app_label",
"django_content_type"."model"
FROM "auth_permission"
inner join "auth_user_user_permissions"
ON ( "auth_permission"."id" =
"auth_user_user_permissions"."permission_id" )
inner join "django_content_type"
ON ( "auth_permission"."content_type_id" =
"django_content_type"."id" )
WHERE "auth_user_user_permissions"."user_id" = %s
ORDER BY "django_content_type"."app_label" ASC,
"django_content_type"."model" ASC,
"auth_permission"."codename" ASC
and:
SELECT "django_content_type"."app_label",
"auth_permission"."codename"
FROM "auth_permission"
inner join "auth_group_permissions"
ON ( "auth_permission"."id" =
"auth_group_permissions"."permission_id" )
inner join "auth_group"
ON ( "auth_group_permissions"."group_id" = "auth_group"."id" )
inner join "auth_user_groups"
ON ( "auth_group"."id" = "auth_user_groups"."group_id" )
left outer join "django_content_type"
ON ( "auth_permission"."content_type_id" =
"django_content_type"."id" )
WHERE "auth_user_groups"."user_id" = %s
my questions are:
What exactly are these queries doing?
Why are they run on
every request? Is there some way to cache these results?
Related
This Redshift query fails -
DELETE FROM TBL_1 stg
WHERE EXISTS (
WITH CCDA as (
SELECT
row_number() OVER (PARTITION BY emp_id,customer_id ORDER BY seq_num desc) rn
, *
FROM TBL_2
WHERE end_dt > (SELECT max(end_dt) FROM TBL_3)
)
SELECT emp_id,customer_id FROM CCDA WHERE rn = 1
AND stg.emp_id = CCDA.emp_id
AND stg.customer_id = CCDA.customer_id
);
Error: Invalid operation: syntax error at or near "stg"
However, the below query runs fine -
SELECT * FROM TBL_1 stg
WHERE EXISTS (
WITH CCDA as (
SELECT
row_number() OVER (PARTITION BY emp_id,customer_id ORDER BY seq_num desc) rn
, *
FROM TBL_2
WHERE end_dt > (SELECT max(end_dt) FROM TBL_3)
)
SELECT emp_id,customer_id FROM CCDA WHERE rn = 1
AND stg.emp_id = CCDA.emp_id
AND stg.customer_id = CCDA.customer_id
);
Am I missing something?
You cannot use an alias in a DELETE statement for the target table. "stg" cannot be used as the alias and this is why you are getting this error.
Also to reference other tables in a DELETE statement you need to use the USING clause.
See: https://docs.aws.amazon.com/redshift/latest/dg/r_DELETE.html
A quick stab of what this would look like (untested):
WITH CCDA as (
SELECT
row_number() OVER (PARTITION BY emp_id,customer_id ORDER BY seq_num desc) rn
, *
FROM TBL_2
WHERE end_dt > (SELECT max(end_dt) FROM TBL_3)
)
DELETE FROM TBL_1
USING CCDA
WHERE CCDA.rn = 1
AND TBL_1.emp_id = CCDA.emp_id
AND TBL_1.customer_id = CCDA.customer_id
;
I want to calculate number of group members (no_members), sum of the points of the group members(point) and average point per person(avg_point) for each group with annotation:
groups = StudyGroup.objects.filter(group_filter).select_related('parent').annotate(
no_members=Count('student', distinct=True),
point=Sum('student__point__point', filter=point_filter),
avg_point=ExpressionWrapper(F('point') / F('no_members'), output_field=FloatField()))
but when I check query (groups.query) in avg_point instead of use point/no_members query is SUM(study_league_point.point) / COUNT(DISTINCT users_student.user_id) (point and no_members calculate again). query is:
SELECT
`study_league_studygroup`.`id`,
`study_league_studygroup`.`name`,
`study_league_studygroup`.`parent_id`,
COUNT(DISTINCT `users_student`.`user_id`) AS `no_members`,
SUM(`study_league_point`.`point`) AS `point`,
(
SUM(`study_league_point`.`point`) / COUNT(DISTINCT `users_student`.`user_id`)
) AS `avg_point`,
`layers_layer`.`id`,
`layers_layer`.`name`,
`layers_layer`.`type_id`,
`layers_layer`.`parent_id`,
`layers_layer`.`created`,
`layers_layer`.`default`,
`layers_layer`.`lft`,
`layers_layer`.`rght`,
`layers_layer`.`tree_id`,
`layers_layer`.`level`
FROM
`study_league_studygroup`
LEFT OUTER JOIN `users_student` ON (
`study_league_studygroup`.`id` = `users_student`.`study_group_id`
)
LEFT OUTER JOIN `study_league_point` ON (
`users_student`.`user_id` = `study_league_point`.`student_id`
)
INNER JOIN `layers_layer` ON (
`study_league_studygroup`.`parent_id` = `layers_layer`.`id`
)
GROUP BY
`study_league_studygroup`.`id`
but I want use (point / no_members) AS avg_point instead of (SUM(study_league_point.point) / COUNT(DISTINCT users_student.user_id)) AS avg_point
I am trying to convert this redshift query to athena.
select
a.customerid,
a.country,
a.stockcode,
a.description,
a.invoicedate,
a.sales_amt,
(b.nbr_months_active) as nbr_months_active
from
ecommerce_sales_data a
inner join (
select
customerid,
count(
distinct(
DATE_PART(y, cast(invoicedate as date)) || '-' || LPAD(
DATE_PART(mon, cast(invoicedate as date)),
2,
'00'
)
)
) as nbr_months_active
from
ecommerce_sales_data
group by
1
) b on a.customerid = b.customerid
This is what I have tried. It returns the results. But I am not sure if the results will match with redshift query in all cases.
WITH students_results(InvoiceNo,StockCode,Description,Quantity,InvoiceDate,UnitPrice,CustomerID,Country) AS (VALUES
('536365','85123A','WHITE HANGING HEART T-LIGHT HOLDER','6','12/1/2010 8:26','2.55','17850','United Kingdom'),
('536365','71053','WHITE METAL LANTERN','6','12/1/2010 8:26','3.39','17850','United Kingdom'),
('536365','84406B','CREAM CUPID HEARTS COAT HANGER','8','12/1/2010 8:26','2.75','17850','United Kingdom')
)
select
a.customerid,
a.country,
a.stockcode,
a.description,
a.invoicedate,
cast(a.quantity as decimal(11,2)) * cast(a.unitprice as decimal(11,2)) as sales_amt,
(b.nbr_months_active) as nbr_months_active
from
students_results a
inner join (
select
customerid,
count(
distinct(
date_format(date_parse(invoicedate,'%m/%d/%Y %k:%i'), '%Y-%m')
)) as nbr_months_active
FROM students_results group by customerid) as b
on a.customerid = b.customerid
The source of Redshift query is here:
https://aws.amazon.com/blogs/machine-learning/build-multi-class-classification-models-with-amazon-redshift-ml/
I have a problem converting below t-sql query into DAX.
Overview - There are two sample tables - Table1 and Table2 with below schema
Table1 (ID varchar(20),Name varchar(30))
Table2 (CapID varchar(20),CAPName varchar(30), CapID_Final varchar(20))
Please note : There exists one to many relationship between above tables : [ID] in Table2 with [CapID] in Table1
I am trying to derive CapID_Final column in table2 based on conditions as per my t-SQL query in below which works perfectly fine -
SELECT CASE
WHEN [CapID] like 'CA%' and [CAPName]='x12345-Sample'
and [CapID] not in(select [ID] from Table1 where Name='x12345-Sample')
THEN 'Undefined_Cap_1'
WHEN [CapID] like 'CA%' and [CAPName]='z12345-Sample'
and [CapID] not in(select [ID] from Table1 where Name='z12345-Sample')
THEN 'Undefined_Cap_2'
WHEN [CapID] like 'CA%' and [CAPName]='a123-Sample'
and [CapID] not in(select [ID] from Table1 where Name='a123-Sample')
THEN 'Undefined'
ELSE [CapID]
END AS [CapID_Final] from Table2
However, I want the same derivation for CapID_Final column in Power BI in a calculated column using DAX.
So far, I have tried below code - but it returns "Undefined" for even matched conditions -
CapID_Final =
IF(LEFT(Table2[CapID],2)="CA" && Table2[CAPName]="z12345-Sample" &&
NOT
(COUNTROWS (
FILTER (
Table1,CONTAINS(Table1,Table1[ID],Table2[CapID])
)
) > 0),"Undefined_Cap_1","Undefined"
)
I am not familiar with DAX, however I tried and couldn't figure it out.
Could you please let me know how to convert my sql query to equivalent DAX in Power BI?
A SWITCH is basically the equivalent of a CASE clause here:
CapID_Final =
SWITCH (
TRUE (),
LEFT ( Table2[CapID], 2 ) = "CA"
&& Table2[CAPName] = "x12345-Sample"
&& NOT (
Table2[CapID]
IN CALCULATETABLE ( VALUES ( Table1[ID] ), Table1[Name] = "x12345-Sample" )
), "Undefined_Cap_1",
LEFT ( Table2[CapID], 2 ) = "CA"
&& Table2[CAPName] = "z12345-Sample"
&& NOT (
Table2[CapID]
IN CALCULATETABLE ( VALUES ( Table1[ID] ), Table1[Name] = "z12345-Sample" )
), "Undefined_Cap_2",
LEFT ( Table2[CapID], 2 ) = "CA"
&& Table2[CAPName] = "a12345-Sample"
&& NOT (
Table2[CapID]
IN CALCULATETABLE ( VALUES ( Table1[ID] ), Table1[Name] = "a12345-Sample" )
), "Undefined",
Table1[CapID]
)
You might even be able to refactor it a bit to be more code efficient. Assuming I didn't make any logic mistakes:
CapID_Final =
VAR IDs =
CALCULATETABLE ( VALUES ( Table1[ID] ), Table1[Name] = Table2[CAPName] )
RETURN
IF (
LEFT ( Table2[CapID], 2 ) = "CA"
&& NOT ( Table2[CapID] IN IDs ),
SWITCH (
Table2[CAPName],
"x12345-Sample", "Undefined_Cap_1",
"z12345-Sample", "Undefined_Cap_2",
"a12345-Sample", "Undefined"
),
Table1[CapID]
)
As a best-practice never use calculated column. In fact, if extensively used they slow down your model refresh and heavily increase your model weight (because they are not compressed). Instead, calculate it in your back-end database or using M Query.
Having said this, the solution to your question is very simple using a SWITCH function:
SWITCH ( <Expression>, <Value>, <Result> [, <Value>, <Result> [, … ] ] [, <Else>] )
In your case would be as follow:
CapIDFinal:=
SWITCH(TRUE(),
AND(CONDITION_1_1, CONDITION_1_2), "Value if condition 1 is true",
AND(CONDITION_2_1, CONDITION_2_2), "Value if condition 2 is true",
"Value if none of above conditions is true
)
How do I do this in doctrine2 QB or DQL.
SELECT * FROM
(
select * from my_table order by timestamp desc
) as my_table_tmp
group by catid
order by nid desc
I think your query is the same as:
SELECT *
FROM my_table
GROUP BY catid
HAVING timestamp = MAX(timestamp)
ORDER BY nid DESC
;
If it is correct, then you should be able to do:
$qb->select('e')
->from('My\Entities\Table', 'e')
->groupBy('e.catid')
->having('e.timestamp = MAX(e.timestamp)')
->orderBy('nid', 'DESC')
;
Or, directly using DQL:
SELECT e
FROM My\Entities\Table e
GROUP BY e.catid
HAVING e.timestamp = MAX(e.timestamp)
ORDER BY e.nid DESC
;
Hope this helps and works! ;)