I need to select from a CTE (common table expression) in DB2 v8 and insert the result into a table.
The relevant documentation for v8 is hard to understand at first glance, but for v9 there's a clear example (http://publib.boulder.ibm.com/infocenter/dzichelp/v2r2/index.jsp?topic=/com.ibm.db29.doc.apsg/db2z_createcte.htm):
INSERT INTO vital_mgr (mgrno)
WITH VITALDEPT (deptno, se_count) AS
(
SELECT deptno, count(*)
FROM DSN8910.EMP
WHERE job = 'senior engineer'
GROUP BY deptno
)
SELECT d.manager
FROM DSN8910.DEPT d
, VITALDEPT s
WHERE d.deptno = s.deptno
AND s.se_count > (
SELECT AVG(se_count)
FROM VITALDEPT
);
It does not work in v8 though.
How should it be written in v8?
Write it like a boss
INSERT INTO vital_mgr
(
SELECT d.manager
FROM SN8910.DEPT AS d
INNER JOIN
(
SELECT deptno, count(*)
FROM DSN8910.EMP
WHERE job = 'senior engineer'
GROUP BY deptno
) AS s (deptno, se_count)
ON d.deptno = s.deptno
WHERE s.se_count > (
SELECT AVG(se_count)
FROM
(
SELECT deptno, count(*)
FROM DSN8910.EMP
WHERE job = 'senior engineer'
GROUP BY deptno
) AS VITALDEPT (deptno, se_count)
)
);
There's a simple workaround here that allows you to use an INSERT or UPDATE using a conventional WITH statement. This hack will work for INSERT on V8 or greater, and for UPDATE on V9 or greater.
There are other methods for V8 or greater, typically using sub-selects, but I find them to be unpractical due to their complexity.
Related
I am using TSQL, SSMS v.17.9.1 The underlying db is Microsoft SQL Server 2014 SP3
For display purposes, I want to concatenate the results of two queries:
SELECT TOP 1 colA as 'myCol1' FROM tableA
--
SELECT TOP 1 colB as 'myCol2' FROM tableB
and display the results from the queries in one row in SSMS.
(The TOP 1 directive would hopefully guarantee the same number of results from each query, which would assist displaying them together. If this could be generalized to TOP 10 per query that would help also)
This should work for any number of rows, it assumes you want to pair ordered by the values in the column displayed
With
TableA_CTE AS
(
SELECT TOP 1 colA as myCol1
,Row_Number() OVER (ORDER BY ColA DESC) AS RowOrder
FROM tableA
),
TableB_CTE AS
(
SELECT TOP 1 colB as myCol2
,Row_Number() OVER (ORDER BY ColB DESC) AS RowOrder
FROM tableB
)
SELECT A.myCol1, B.MyCol2
FROM TableA_CTE AS A
INNER JOIN TableB_CTE AS B
ON A.RowOrder = B.RowOrder
There are currently two issues with the accepted answer:
I) a missing comma before the line: "Table B As"
II) TSQL seems to find it recursive as written, so I re-wrote it in a non-recursive way:
This is a re-working of the accepted answer that actually works in T-SQL:
USE [Database_1];
With
CTE_A AS
(
SELECT TOP 1 [Col1] as myCol1
,Row_Number() OVER (ORDER BY [Col2] desc) AS RowOrder
FROM [TableA]
)
,
CTE_B AS
(
SELECT TOP 1 [Col2] as myCol2
,Row_Number() OVER (ORDER BY [Col2] desc) AS RowOrder
FROM [TableB]
)
SELECT A.myCol1, B.myCol2
FROM CTE_A AS A
INNER JOIN CTE_B AS B
ON ( A.RowOrder = B.RowOrder)
I want to create calculated table that will summarize In_Force Premium from existing table fact_Premium.
How can I filter the result by saying:
TODAY() has to be between `fact_Premium[EffectiveDate]` and (SELECT TOP 1 fact_Premium[ExpirationDate] ORDE BY QuoteID DESC)
In SQL I'd do that like this:
`WHERE CONVERT(date, getdate()) between CONVERT(date, tblQuotes.EffectiveDate)
and (
select top 1 q2.ExpirationDate
from Table2 Q2
where q2.ControlNo = Table1.controlno
order by quoteid` desc
)
Here is my DAX statement so far:
In_Force Premium =
FILTER(
ADDCOLUMNS(
SUMMARIZE(
//Grouping necessary columns
fact_Premium,
fact_Premium[QuoteID],
fact_Premium[Division],
fact_Premium[Office],
dim_Company[CompanyGUID],
fact_Premium[LineGUID],
fact_Premium[ProducerGUID],
fact_Premium[StateID],
fact_Premium[ExpirationDate]
),
"Premium", CALCULATE(
SUM(fact_Premium[Premium])
),
"ControlNo", CALCULATE(
DISTINCTCOUNT(fact_Premium[ControlNo])
)
), // Here I need to make sure TODAY() falls between fact_Premium[EffectiveDate] and (SELECT TOP 1 fact_Premium[ExpirationDate] ORDE BY QuoteID DESC)
)
Also, what would be more efficient way, to create calculated table from fact_Premium or create same table using sql statement (--> Get Data--> SQL Server) ?
There are 2 potential ways in T-SQL to get the next effective date. One is to use LEAD() and another is to use an APPLY operator. As there are few facts to work with here are samples:
select *
from (
select *
, lead(EffectiveDate) over(partition by CompanyGUID order by quoteid desc) as NextEffectiveDate
from Table1
join Table2 on ...
) d
or
select table1.*, oa.NextEffectiveDate
from Table1
outer apply (
select top(1) q2.ExpirationDate AS NextEffectiveDate
from Table2 Q2
where q2.ControlNo = Table1.controlno
order by quoteid desc
) oa
nb. an outer apply is a little similar to a left join in that it will allow rows with a NULL to be returned by the query, if that is not needed than use cross apply instead.
In both these approaches you may refer to NextEffectiveDate in a final where clause, but I would prefer to avoid using the convert function if that is feasible (this depends on the data).
I have a query I need to run that returns the most recently updated row for each client.
In SQL Server, I would do the following:
SELECT *
FROM
(
SELECT *, ROW_NUMBER() OVER (PARTITION BY client_id ORDER BY date_updated DESC) AS rn
FROM client_address
) a
WHERE a.rn = 1
Is there a similar way to do this on Intersystems Cache? I'm not finding any documentation for any type of ranking function.
I looked at the docs and the doesn't appear to be any of the Window functions that exist in SQL Server, Oracle or Postgres so you're stuck with the ANTI-THETA-SELF-JOIN solution.
SELECT *
FROM
client_address a
LEFT JOIN client_address b
on a.client_id = b.client_id
and a.date_updated < b.date_updated
WHERE
b.client_id is null
See the documentation for HAVING. Here's how to use it in this case:
SELECT *
FROM client_address
GROUP BY client_id
HAVING date_updated = MIN(date_updated)
You can use %vid variable. For example:
SELECT *, %vid FROM (SELECT * FROM Sample.Person) WHERE %vid BETWEEN 5 AND 10
would return rows 5-10 from Sample.Person table.
Documentation.
Discussion on InterSystems Caché developer community.
SELECT *
FROM client_address a
WHERE
a.date_updated = (
SELECT max(b.date_updated) FROM client_address b
group by b.Client_id
)
I'm trying to update a column (pop_1_rank) in a postgresql table with the results from a rank() like so:
UPDATE database_final_form_merge
SET
pop_1_rank = r.rnk
FROM (
SELECT pop_1, RANK() OVER ( ORDER BY pop_1 DESC) FROM database_final_form_merge WHERE territory_name != 'north' AS rnk)r
The SELECT query by itself works fine, but I just can't get it to update correctly. What am I doing wrong here?
I rather use the CTE notation.
WITH cte as (
SELECT pop_1,
RANK() OVER ( ORDER BY pop_1 DESC) AS rnk
FROM database_final_form_merge
WHERE territory_name <> 'north'
)
UPDATE database_final_form_merge
SET pop_1_rank = cte.rnk
FROM cte
WHERE database_final_form_merge.pop_1 = cte.pop_1
As far as I know, Postgres updates tables not subqueries. So, you can join back to the table:
UPDATE database_final_form_merge
SET pop_1_rank = r.rnk
FROM (SELECT pop_1, RANK() OVER ( ORDER BY pop_1 DESC) as rnk
FROM database_final_form_merge
WHERE territory_name <> 'north'
) r
WHERE database_final_form_merge.pop_1 = r.pop_1;
In addition:
The column alias goes by the column name.
This assumes that pop_1 is the id connecting the two tables.
You're missing WHERE on UPDATE query, because when doing UPDATE ... FROM you're basically doing joins.
So you need to select primary key and then match on primary key to update just the columns are computing rank over.
Is it possible to use the value of EXISTS as part of a query?
(Please note: unfortunately due to client constraints, I need SQLServer 2005 compatible answers!)
So when returning a set of results, one of the columns is a boolean value which states whether the subquery would return any rows.
For example, I want to return a list of usernames and whether a different table contains any rows for each user. The following is not syntactically correct, but hopefully gives you an idea of what I mean...
SELECT T1.[UserName],
(EXISTS (SELECT *
FROM [AnotherTable] T2
WHERE T1.[UserName] = T2.[UserName])
) AS [RowsExist]
FROM [UserTable] T1
Where the resultant set contains a column called [UserName] and boolean column called [RowsExist].
The obvious solution is to use a CASE, such as below, but I wondered if there was a better way of doing it...
SELECT T1.[UserName],
(CASE (SELECT COUNT(*)
FROM [AnotherTable] T2
WHERE T1.[UserName] = T2.[UserName]
)
WHEN 0 THEN CAST(0 AS BIT)
ELSE CAST(1 AS BIT) END
) AS [RowsExist]
FROM [UserTable] T1
Your second query isn't valid syntax.
SELECT T1.[UserName],
CASE
WHEN EXISTS (SELECT *
FROM [AnotherTable] T2
WHERE T1.[UserName] = T2.[UserName]) THEN CAST(1 AS BIT)
ELSE CAST(0 AS BIT)
END AS [RowsExist]
FROM [UserTable] T1
Is generally fine and will be implemented as a semi join.
The article Subqueries in CASE Expressions discusses this further.
In some cases a COUNT query can actually perform better though as discussed here
I like the other guys sql better but i just wrote this:
with bla as (
select t2.username, isPresent=CAST(1 AS BIT)
from t2
group by t2.username
)
select t1.*, isPresent = isnull(bla.isPresent, CAST(0 AS BIT))
from t1
left join blah on t1.username=blah.username
From what you wrote here I would alter your first query into something like this
SELECT
T1.[UserName], ISNULL(
(
SELECT
TOP 1 1
FROM [AnotherTable]
WHERE EXISTS
(
SELECT
1
FROM [AnotherTable] AS T2
WHERE T1.[UserName] = T2.[UserName]
)
), 0)
FROM [UserTable] T1
But actually if you use TOP 1 1 you would not need EXISTS, you could also write
SELECT
T1.[UserName], ISNULL(
(
SELECT
TOP 1 1
FROM [AnotherTable] AS T2
WHERE T1.[UserName] = T2.[UserName]
), 0)
FROM [UserTable] T1