I'm a SQL Server guy and I have a need to write some dynamic SQL in Postgres. Here's what I need. The dynamic SQL would be dependent upon integers produced by this query:
SELECT local_channel_id
FROM d_channels dc
INNER JOIN channel c ON c.id = dc.channel_id
AND c.name LIKE '%__Achv'
Using this, I need to build and execute a select and subsequent union select on the below query substituting the the values produced by the above query where indicated below by {X} (4 places):
SELECT
dmc.message_id,
dmm.received_date,
dmm.server_id,
dc.channel_id,
dmcm."SOURCE",
dmcm."TYPE",
dmm.status,
dmc.content
FROM
d_mc{X} dmc
INNER JOIN
d_mm{X} dmm ON dmc.message_id = dmm.message_id
INNER JOIN
d_channels dc ON dc.local_channel_id = {X}
INNER JOIN
d_mcm{X} dmcm ON dmcm.message_id = dmc.message_id
AND dmcm.metadata_id = 0
WHERE
dmm.connector_name = 'Source'
AND dmc.content_type = 1 --Raw
AND date(dmm.received_date) + interval '7' < now()
Can anybody help with this? I'm truly clueless when it comes to Postgres.
Related
I'm trying to get lateral to work in a Postgres 9.5.3 query.
select b_ci."IdOwner",
ci."MinimumPlaces",
ci."MaximumPlaces",
(select count(*) from "LNK_Stu_CI" lnk
where lnk."FK_CourseInstanceId" = b_ci."Id") as "EnrolledStudents",
from "Course" c
join "DBObjectBases" b_c on c."Id" = b_c."Id"
join "DBObjectBases" b_ci on b_ci."IdOwner" = b_c."Id"
join "CourseInstance" ci on ci."Id" = b_ci."Id",
lateral (select ci."MaximumPlaces" - "EnrolledStudents") x
I want the right-most column to be the result of "MaximumPlaces" - "EnrolledStudents" for that row but am struggling to get it to work. At the moment PG is complaining that "EnrolledStudents" does not exist - which is exactly the point of "lateral", isn't it?
select b_ci."IdOwner",
ci."MinimumPlaces",
ci."MaximumPlaces",
(select count(*) from "LNK_Stu_CI" lnk
where lnk."FK_CourseInstanceId" = b_ci."Id") as "EnrolledStudents",
lateral (select "MaximumPlaces" - "EnrolledStudents") as "x"
from "Course" c
join "DBObjectBases" b_c on c."Id" = b_c."Id"
join "DBObjectBases" b_ci on b_ci."IdOwner" = b_c."Id"
join "CourseInstance" ci on ci."Id" = b_ci."Id"
If I try inlining the lateral clause (shown above) in the select it gets upset too and gives me a syntax error - so where does it go?
Thanks,
Adam.
You are missing the point with LATERAL. It can access columns in tables in the FROM clause, but not aliases defined in SELECT clause.
If you want to access alias defined in SELECT clause, you need to add another query level, either using a subquery in FROM clause (AKA derived table) or using a CTE (Common Table Expression). As CTE in PostgreSQL acts as an optimization fence, I strongly recommend going with subquery in this case, like:
select
-- get all columns on the inner query
t.*,
-- get your new expression based on the ones defined in the inner query
t."MaximumPlaces" - t."EnrolledStudents" AS new_alias
from (
select b_ci."IdOwner",
ci."MinimumPlaces",
ci."MaximumPlaces",
(select count(*) from "LNK_Stu_CI" lnk
where lnk."FK_CourseInstanceId" = b_ci."Id") as "EnrolledStudents",
from "Course" c
join "DBObjectBases" b_c on c."Id" = b_c."Id"
join "DBObjectBases" b_ci on b_ci."IdOwner" = b_c."Id"
join "CourseInstance" ci on ci."Id" = b_ci."Id"
) t
I have a SQL query I want to write in LINQ
Here is my Query
SELECT DISTINCT *
FROM [IHQDB].[dbo].[Table1] as t1
inner join Table2 as t2 on t2.Table2 =t1.ChangedItemID
inner join Table3 as t3 on t3.Table3 = t1.FromUserID
where (t1.FromUserID=1 And t2.ContentItemID= t1.ChangedItemID)
OR (t2.LastModifiedBy=1 or t2.CreatedBy=1 )
Hi now its working fine but My query little bit different on place of 1 I need my userID on base of their First Name and Last Name from M_User table.
How can I get UserId on Base of First Name + Last Name.
Here is my LINQ CODE For Retrieving User Name
linq4 = from q in context.T_ContentItems
join p in context.M_Users on q.CreatedBy equals p.UserID
where (advanceKeyword.Contains(p.EmployeeFirstName + " " + p.EmployeeLastName)) select q;
advancechk12 = linq4.ToList();
========================================================================
What I require is that wherever I have written the value "1" (e.g. t2.CreatedBy=1), I need to find the UserID. For simplicity, I am able to get the names of all the filtered users in the advancechk12. How do I retrieve the UserID's of the list of usernames returned in advancechk12
You have to replace below mentioned Linq query with your models name.I just used the same name of the T-Sql.
var t1List = (from t1 in db.Table1
join t2 in db.Table2 on t1.ChangedItemID equals t2.Id
join t3 in db.Table3 on t3.Id equals t1.FromUserID
where ((t1.FromUserID=1 && t2.ContentItemID= t1.ChangedItemID) || (t2.LastModifiedBy=1 or t2.CreatedBy=1))
select t1).Distinct().ToList();
I'm having trouble with paginating with joined tables in DB2. I want to return rows 10-30 of a query that contains an INNER JOIN.
This works:
SELECT *
FROM (
SELECT row_number() OVER (ORDER BY U4SLSMN.SLNAME) AS ID,
U4SLSMN.SLNO, U4SLSMN.SLNAME, U4SLSMN.SLLC
FROM U4SLSMN) AS P
WHERE P.ID BETWEEN 10 AND 30
This does not work:
SELECT *
FROM (
SELECT row_number() OVER (ORDER BY U4SLSMN.SLNAME) AS ID,
U4SLSMN.SLNO, U4SLSMN.SLNAME, U4SLSMN.SLLC, U4CONST.C4NAME
FROM U4SLSMN INNER JOIN U4CONST ON U4SLSMN.SLNO = U4CONST.C4NAME
) AS P
WHERE P.ID BETWEEN 10 AND 30
The error I get is:
Selection error involving field *N.
Note that the JOIN query works correctly by itself, just not when it's run as a subquery.
How do I perform a join inside a subquery in DB2?
Works fine for me on v7.1 TR9
Here's what I actually ran:
select *
from ( select rownumber() over (order by vvname) as ID, idescr, vvname
from olsdta.ioritemmst
inner join olsdta.vorvendmst on ivndno = vvndno
) as P
where p.id between 10 and 30;
I much prefer the CTE version however:
with p as
( select rownumber() over (order by vvname) as ID, idescr, vvname
from olsdta.ioritemmst
inner join olsdta.vorvendmst on ivndno = vvndno
)
select *
from p
where p.id between 10 and 30;
Finally, note that at 7.1 TR11 (7.2 TR3), IBM added support of the LIMIT and OFFSET clauses. Your query could be re-done as follows:
SELECT
U4SLSMN.SLNO, U4SLSMN.SLNAME, U4SLSMN.SLLC, U4CONST.C4NAME
FROM U4SLSMN INNER JOIN U4CONST ON U4SLSMN.SLNO = U4CONST.C4NAME
ORDER BY U4SLSMN.SLNAME
LIMIT 20 OFFSET 9;
However, note that the LIMIT & OFFSET clauses are only supported in prepared or embedded SQL. You can't use them in STRSQL or STRQMQRY. I believe the "Run SQL Scripts" GUI interface does support them. Here's an article about LIMIT & OFFSET
Assume I have a query like this:
SELECT *
FROM clients c
INNER JOIN clients_balances cb ON cb.id_clients = c.id
LEFT JOIN clients com ON com.id = c.id_companies
LEFT JOIN clients com_real ON com_real.id = c.id_companies_real
LEFT JOIN rate_tables rt_orig ON rt_orig.id = c.orig_rate_table
LEFT JOIN rate_tables rt_term ON rt_term.id = c.term_rate_table
LEFT JOIN payment_terms pt ON pt.id = c.id_payment_terms
LEFT JOIN paygw_clients_profiles cpgw ON (cpgw.id_clients = c.id AND cpgw.id_companies = c.id_companies_real)
WHERE
EXISTS (SELECT * FROM accounts WHERE (name LIKE 'x' OR accname LIKE 'x' OR ani LIKE 'x') AND id_clients = c.id)
AND c."type" = '0'
AND c."id" > 0
ORDER BY c."name";
This query takes around 35 seconds to run when used in the production environment ("clients" has about 1 million records). However, if I take out ANY join - the query will take only about 300 ms to execute.
I've played around with the query planner settings, but to no avail.
Here are a few explain analyze outputs:
http://explain.depesz.com/s/hzy (slow - 48049.574 ms)
http://explain.depesz.com/s/FWCd (fast - 286.234 ms, rate_tables JOIN removed)
http://explain.depesz.com/s/MyRf (fast - 539.733 ms, paygw_clients_profiles JOIN removed)
It looks like in the fast case the planner starts from the EXISTS statement and has to perform join for only two rows in total. However, in the slow case it will first join all the tables and then filter by EXISTS.
What I need to do is to make this query run in a reasonable time with all seven join in place.
Postgres version is 9.3.10 on CentOS 6.3.
Thanks.
UPDATE
Rewriting the query like this:
SELECT *
FROM clients c
INNER JOIN clients_balances cb ON cb.id_clients = c.id
INNER JOIN accounts a ON a.id_clients = c.id AND (a.name = 'x' OR a.accname = 'x' OR a.ani = 'x')
LEFT JOIN clients com ON com.id = c.id_companies
LEFT JOIN clients com_real ON com_real.id = c.id_companies_real
LEFT JOIN rate_tables rt_orig ON rt_orig.id = c.orig_rate_table
LEFT JOIN rate_tables rt_term ON rt_term.id = c.term_rate_table
LEFT JOIN payment_terms pt ON pt.id = c.id_payment_terms
LEFT JOIN paygw_clients_profiles cpgw ON (cpgw.id_clients = c.id AND cpgw.id_companies = c.id_companies_real)
WHERE
c."type" = '0' AND c.id > 0
ORDER BY c."name";
makes it run fast, however, this is not acceptable, as account filtration parameters are optional, and I still need the result if there are no matches in that table. Using "LEFT JOIN accounts" instead of "INNER JOIN accounts" kills the performance again.
As suggested by Tome Lane, I've changed the following two parameters: join_collapse_limit and from_collapse_limit to 10 instead of the default 8, and this solved the issue.
How would I redesign the below query so that it will recursively loop through entire tree to return all descendants from root to leaves? (I'm using SSMS 2008). We have a President at the root. under him are the VPs, then upper management, etc., on down the line. I need to return the names and titles of each. But this query shouldn't be hard-coded; I need to be able to run this for any selected employee, not just the president. This query below is the hard-coded approach.
select P.staff_name [Level1],
P.job_title [Level1 Title],
Q.license_number [License 1],
E.staff_name [Level2],
E.job_title [Level2 Title],
G.staff_name [Level3],
G.job_title [Level3 Title]
from staff_view A
left join staff_site_link_expanded_view P on P.people_id = A.people_id
left join staff_site_link_expanded_view E on E.people_id = C.people_id
left join staff_site_link_expanded_view G on G.people_id = F.people_id
left join facility_view Q on Q.group_profile_id = P.group_profile_id
Thank you, this was most closely matching what I needed. Here is my CTE query below:
with Employee_Hierarchy (staff_name, job_title, id_number, billing_staff_credentials_code, site_name, group_profile_id, license_number, region_description, people_id)
as
(
select C.staff_name, C.job_title, C.id_number, C.billing_staff_credentials_code, C.site_name, C.group_profile_id, Q.license_number, R.region_description, A.people_id
from staff_view A
left join staff_site_link_expanded_view C on C.people_id = A.people_id
left join facility_view Q on Q.group_profile_id = C.group_profile_id
left join regions R on R.regions_id = Q.regions_id
where A.last_name = 'kromer'
)
select C.staff_name, C.job_title, C.id_number, C.billing_staff_credentials_code, C.site_name, C.group_profile_id, Q.license_number, R.region_description, A.people_id
from staff_view A
left join staff_site_link_expanded_view C on C.people_id = A.people_id
left join facility_view Q on Q.group_profile_id = C.group_profile_id
left join regions R on R.regions_id = Q.regions_id
WHERE C.STAFF_NAME IS NOT NULL
GROUP BY C.STAFF_NAME, C.job_title, C.id_number, C.billing_staff_credentials_code, C.site_name, C.group_profile_id, Q.license_number, R.region_description, A.people_id
ORDER BY C.STAFF_NAME
But I am wondering what is the purpose of the "Employee_Hierarchy"? When I replaced "staff_view" in the outer query with "Employee_Hierarchy", it only returned one record = "Kromer". So when/where can we use "Employee_Hierarchy"?
See:
SQL Server - Simple example of a recursive CTE
MSDN: Recursive Queries using Common Table Expression
SQL Server recursive CTE (this seems pretty much like exactly what you are working on!)
Update:
A proper recursive CTE consist of basically three things:
an anchor SELECT to begin with; that can select e.g. the root level employees (where the Reports_To is NULL), or it can select any arbitrary employee that you define, e.g. by a parameter
a UNION ALL
a recursive SELECT statement that selects from the same, typically self-referencing table and joins with the recursive CTE being currently built up
This gives you the ability to recursively build up a result set that you can then select from.
If you look at the Northwind sample database, it has a table called Employees which is self-referencing: Employees.ReportsTo --> Employees.EmployeeID defines who reports to whom.
Your CTE would look something like this:
;WITH RecursiveCTE AS
(
-- anchor query; get the CEO
SELECT EmployeeID, FirstName, LastName, Title, 1 AS 'Level', ReportsTo
FROM dbo.Employees
WHERE ReportsTo IS NULL
UNION ALL
-- recursive part; select next Employees that have ReportsTo -> cte.EmployeeID
SELECT
e.EmployeeID, e.FirstName, e.LastName, e.Title,
cte.Level + 1 AS 'Level', e.ReportsTo
FROM
dbo.Employees e
INNER JOIN
RecursiveCTE cte ON e.ReportsTo = cte.EmployeeID
)
SELECT *
FROM RecursiveCTE
ORDER BY Level, LastName
I don't know if you can translate your sample to a proper recursive CTE - but that's basically the gist of it: anchor query, UNION ALL, recursive query