how can use loop or IF in case when statements in postgresql - postgresql

select distinct
x.vrgid, x.Weights, x.geom
from
(select
-- postcodes.id as postcodeid ,,fishnet.geom as geom
fishnet.gid as vrgid,
fishnet.geom as geom,
CASE WHEN
st_intersects(centroids.geom, urban.geom) and counts.nonurbancells != 0
THEN 0.95 :: numeric / counts.urbancells -------1st case
WHEN st_intersects(centroids.geom, urban.geom) and counts.nonurbancells = 0
THEN 1.00 :: numeric / counts.urbancells ---2ndcase
WHEN Not st_intersects(centroids.geom, urban.geom) = fishnet.gid :: boolean and counts.nonurbancells != 0
THEN 0.05 :: numeric / counts.nonurbancells ----3rd case
ELSE 0
END AS Weights
from vrg.urban_nonurban_count_new as counts
inner join vrg.gfk_2016_id_5_digit_pcd_areas2013_projected as postcodes on postcodes.id = counts.postid
right outer join vrg.rdsid_86_quadgrid_centroids as centroids on st_contains(postcodes.geom, centroids.geom)
left outer join vrg.rdsid86_quadgrid AS fishnet on fishnet.gid = centroids.gid
right outer join vrg.rdsid86_katrisk_poly_projected as urban on st_intersects(urban.geom, fishnet.geom)
where postcodes.id = '42395') as x
I have several case statements in my PL/Pgsql function in which the I get duplicate rows (with duplicate vrgids). Below is the query result
Here (the marked row) with id 7192 is the result of 1st case statement(refer the query)
What I would like to do is use loop or if condition to remove the vrgid and corresponding weights from the result once the 1st case statement is true.
So thet I won't get duplicate records. How is it possible?
May be I should use a condition in 3rd statement to result out the vrgids not present in 1st case statement.

Related

How to have CASE statement look at previous records in the statement

I have the following code generating a case statement in which I would like all future time periods to return 'Graduated' if the student graduated in a previous time period. Here is the current code:
SELECT DISTINCT
Z1.StudentID,
Z1.AcadLevel,
Z1.StudentAcadLevel,
Z1.StudentCohortStartDate,
Z1.PeriodID,
Z2.CourseTimePeriod,
Z3.DegreeTimePeriod,
CASE
WHEN Z1.PeriodID = '0' THEN 'CohortStart'
WHEN Z3.DegreeTimePeriod <= Z1.PeriodID THEN 'Graduated'
WHEN Z1.PeriodID = Z2.CourseTimePeriod THEN 'Retained'
WHEN Z2.CourseTimePeriod IS NULL THEN 'Churned'
ELSE 'Fix Me'
END AS TimePeriodStatus
FROM Z_Retention_StudentTimePeriodStatus Z1
LEFT OUTER JOIN Z_Retention_StudentCourseRegistrations Z2 ON Z2.StudentID = Z1.StudentID AND Z2.STC_ACAD_LEVEL = Z1.AcadLevel AND Z2.CourseTimePeriod = Z1.PeriodID
LEFT OUTER JOIN Z_Retention_StudentDegree Z3 ON Z3.StudentID = Z1.StudentID AND Z3.DegreeAcadLevel = Z1.AcadLevel AND Z3.DegreeTimePeriod = Z1.PeriodID
ORDER BY Z1.StudentID, Z1.PeriodID, Z2.CourseTimePeriod
In the attached image, I'm hoping to add a line to the case statement that would make the highlighted rows return 'Graduated' rather than 'Churned'.

Query returning different number of rows, results in crosstab error

I get this error with my query, but I can't figure out what is wrong with it:
Query-specified return tuple has 135 columns but crosstab returns 295.
And here's my query: (The part highlighted in bold returns same number of rows when run separately in pgAdmin.)
SELECT X.*, pi.productcode, pi.productitemdesc, pi.retailsalesprice, cat.productcategorydesc FROM (
SELECT * FROM crosstab (
'SELECT a.productitem AS productitemid, l.locationcode, (CASE WHEN SUM(a.netamount) IS NOT NULL THEN SUM(a.netamount) ELSE 0 END) || ''#'' || (CASE WHEN SUM(a.quantity) IS NOT NULL THEN SUM(a.quantity) ELSE 0 END) AS sales_qty FROM invoiceitem a INNER JOIN invoiceinfo b ON a.invoice = b.invoiceid INNER JOIN locationinfo l ON b.location = l.locationid WHERE b.status !=2 AND l.locationtype = 1 AND l.status = 1 AND TO_CHAR (b.invoicedate, ''YYYY-MM-DD'')>=''2018-03-01'' AND TO_CHAR (b.invoicedate, ''YYYY-MM-DD'')<=''2018-03-03'' GROUP BY a.productitem, l.locationcode ORDER BY a.productitem',
'SELECT l.locationcode FROM locationinfo l INNER JOIN invoiceinfo b ON b.location = l.locationid
WHERE b.status !=2 AND l.locationtype = 1 AND l.status = 1 AND TO_CHAR (b.invoicedate, ''YYYY-MM-DD'')>=''2018-03-01'' AND TO_CHAR (b.invoicedate, ''YYYY-MM-DD'')<=''2018-03-03'' GROUP BY l.locationcode order by l.locationcode')
AS (productitemid int, "0007" text,"BE101" text,"BE1013" text,"BE1014" text,"BE102" text,"BE103" text,"BE1034" text,"BE104" text,"BE1040" text,"BE1043" text,"BE1044" text,"BE1045" text,"BE1046" text,"BE105" text,"BE106" text,"BE107" text,"BE108" text,"BE109" text,"BE110" text,"BE111" text,"BE112" text,"BE123" text,"BE1265" text,"BE1266" text,"BE1271" text,"BE1272" text,"BE1273" text,"BE1274" text,"BE1279" text,"BE1280" text,"BE1281" text,"BE1282" text,"BE1351" text,"BE1400" text,"BE1401" text,"BE1404" text,"BE141" text,"BE142" text,"BE193" text,"BE194" text,"BE2125" text,"BE2126" text,"BE2127" text,"BE2128" text,"BE3001" text,"BE3002" text,"BE3005" text,"BE3006" text,"BE3009" text,"BE3010" text,"BE3031" text,"BE3032" text,"BE3121" text,"BE3122" text,"BE3123" text,"BE3124" text,"BE3127" text,"BE3128" text,"BE3131" text,"BE3132" text,"BE3203" text,"BE3204" text,"BE325" text,"BE3253" text,"BE3254" text,"BE326" text,"BE332" text,"BE3503" text,"BE3504" text,"BE355" text,"BE356" text,"BE365" text,"BE366" text,"BE381" text,"BE382" text,"BE383" text,"BE384" text,"BE400" text,"BE401" text,"BE402" text,"BE403" text,"BE405" text,"BE406" text,"BE408" text,"BE409" text,"BE411" text,"BE412" text,"BE4311" text,"BE4316" text,"BE4401" text,"BE4402" text,"BE4521" text,"BE4522" text,"BE4551" text,"BE4552" text,"BE470" text,"BE473" text,"BE475" text,"BE481" text,"BE482" text,"BE601" text,"BE604" text,"BE609" text,"BE610" text,"BE7040" text,"BE7043" text,"BE7045" text,"BE7046" text,"BE7048" text,"BE7049" text,"BE708" text,"BE7111" text,"BE7112" text,"BE7127" text,"BE7128" text,"BE7217" text,"BE7218" text,"BE7307" text,"BE7308" text,"BE7351" text,"BE7352" text,"BE801" text,"BE802" text,"BE803" text,"BE804" text,"BE831" text,"BE832" text,"BE860" text,"BE861" text,"BE862" text,"BE863" text,"BE865" text,"BE981" text,"BE982" text
)) X
LEFT JOIN productitem pi ON X.productitemid = pi.productitemid
LEFT JOIN productcategory cat ON pi.productcategory = cat.productcategoryid
The bold part of
productitemid int, "0007" text,"BE101" text,"BE1013" text,"BE1014" text,"BE102" text,"BE103" text,"BE1034" text,"BE104" text,"BE1040" text,"BE1043" text,"BE1044" text,"BE1045" text,"BE1046" text,"BE105" text,"BE106" text,"BE107" text,"BE108" text,"BE109" text,"BE110" text,"BE111" text,"BE112" text,"BE123" text,"BE1265" text,"BE1266" text,"BE1271" text,"BE1272" text,"BE1273" text,"BE1274" text,"BE1279" text,"BE1280" text,"BE1281" text,"BE1282" text,"BE1351" text,"BE1400" text,"BE1401" text,"BE1404" text,"BE141" text,"BE142" text,"BE193" text,"BE194" text,"BE2125" text,"BE2126" text,"BE2127" text,"BE2128" text,"BE3001" text,"BE3002" text,"BE3005" text,"BE3006" text,"BE3009" text,"BE3010" text,"BE3031" text,"BE3032" text,"BE3121" text,"BE3122" text,"BE3123" text,"BE3124" text,"BE3127" text,"BE3128" text,"BE3131" text,"BE3132" text,"BE3203" text,"BE3204" text,"BE325" text,"BE3253" text,"BE3254" text,"BE326" text,"BE332" text,"BE3503" text,"BE3504" text,"BE355" text,"BE356" text,"BE365" text,"BE366" text,"BE381" text,"BE382" text,"BE383" text,"BE384" text,"BE400" text,"BE401" text,"BE402" text,"BE403" text,"BE405" text,"BE406" text,"BE408" text,"BE409" text,"BE411" text,"BE412" text,"BE4311" text,"BE4316" text,"BE4401" text,"BE4402" text,"BE4521" text,"BE4522" text,"BE4551" text,"BE4552" text,"BE470" text,"BE473" text,"BE475" text,"BE481" text,"BE482" text,"BE601" text,"BE604" text,"BE609" text,"BE610" text,"BE7040" text,"BE7043" text,"BE7045" text,"BE7046" text,"BE7048" text,"BE7049" text,"BE708" text,"BE7111" text,"BE7112" text,"BE7127" text,"BE7128" text,"BE7217" text,"BE7218" text,"BE7307" text,"BE7308" text,"BE7351" text,"BE7352" text,"BE801" text,"BE802" text,"BE803" text,"BE804" text,"BE831" text,"BE832" text,"BE860" text,"BE861" text,"BE862" text,"BE863" text,"BE865" text,"BE981" text,"BE982" text
AND
SELECT l.locationcode FROM locationinfo l INNER JOIN invoiceinfo b ON b.location = l.locationid
WHERE b.status !=2 AND l.locationtype = 1 AND l.status = 1 AND TO_CHAR (b.invoicedate, ''YYYY-MM-DD'')>=''2018-03-01'' AND TO_CHAR (b.invoicedate, ''YYYY-MM-DD'')<=''2018-03-03'' GROUP BY l.locationcode order by l.locationcode
When run seperately, I get 295 results which is correct. However putting it together in the whole query gets the error.

The manual:
The remaining output columns must have the type of the last column of the source_sql query's result, and there must be exactly as many of them as there are rows in the category_sql query's result.
crosstab(text, text) with a dynamic (!) SELECT query as 2nd parameter is very error prone, since the output column list is static. You should also generate the output column list dynamically. Example:
Dynamic alternative to pivot with CASE and GROUP BY
That aside, the different number of rows returned from the same query, may very well be due to a different timezone setting in the two different sessions.
You have the expression TO_CHAR(b.invoicedate, 'YYYY-MM-DD') in your predicates. If b.invoicedate is type timestamptz the result depends on the timezone setting. Consider:
SET timezone = '+10';
SELECT TO_CHAR(timestamptz '2018-04-07 23:30+0', 'YYYY-MM-DD');
to_char
----------
2018-04-08
SET timezone = '-10';
SELECT TO_CHAR(timestamptz '2018-04-07 23:30+0', 'YYYY-MM-DD');
to_char
----------
2018-04-07
Solution
To remove the dependency on the timezone setting, use absolute values.
to_char() is expensive complication in this place to begin with. Drop that and adjust the predicate.
Provide timestamptz values to match your column. This also allows indexes to be used (if applicable).
Return Table Type from A function in PostgreSQL
Use time zone names (not offsets or abbreviations) to avoid more misunderstandings.
Ignoring timezones altogether in Rails and PostgreSQL
Use dollar-quoting to clean up the quote mess.
Insert text with single quotes in PostgreSQL
I suggest this as 2nd parameter:
$$
SELECT l.locationcode
FROM locationinfo l
JOIN invoiceinfo b ON b.location = l.locationid
WHERE b.status <> 2 AND l.locationtype = 1 AND l.status = 1
AND b.invoicedate >= timestamptz '2018-03-01 Europe/Vienna'
AND b.invoicedate < timestamptz '2018-03-04 Europe/Vienna'
GROUP BY 1
ORDER BY 1
$$
Replace Europe/Vienna in my example with the time zone name defining your dates.
Note 2018-03-04 to include all of 2018-03-03 like you intended.

unable to access case statement output from outer query.

I am trying to execute the following query in SSMS 2014. However, I am unable to access from the outer query, the column created using a case statement in the inner query. i.e.I am not able to access c.current.
Error obtained - Incorrect syntax near C
select C.trandate,C.plan,C.current from
(SELECT d.trandate,p.plan,
case when datediff(dd,trandate,getdate()) <=30 then d.amount else 0 end as 'Current',
case when datediff(dd,trandate,getdate()) between 31 and 60 then d.amount else 0 end as '31 to 60',
case when datediff(dd,trandate,getdate()) between 331 and 360 then d.amount else 0 end as '331 to 360',
case when datediff(dd,trandate,getdate()) > 360 then d.amount else 0 end as '>360',d.residentsys
FROM [HMXals_Reporting].[dbo].[TranARDetail] d
join [HMXals_Reporting].[dbo].[plans] p
on d.transys = p.plansys
) C

plan and current are both reserved keywords.
You'll have to go with
select C.trandate, C.[plan], C.[current] from
or choose other names.

need to translate specific t-sql case in pl/sql

Can anyone tell me how to translate the following T-SQL statement:
SELECT fileld1 = CASE
WHEN T.option1 THEN -1
ELSE
CASE WHEN T.option2 THEN 0
ELSE 1
END
END
FROM Table1 AS T
The point is I need to validate two different options from the table for a single field in the select statement..
I have tried to do somthing with an IF statement in pl/sql, but it just doesnt work for me:
SELECT IF T.option1 THEN -1
ELSE IF T.option2 THEN 0
ELSE 1
END
FROM Table1 AS T
I am not actually sure how to write IF statement inside the SELECT statement..
And also, I need to do it INSIDE the select statement because I am constructing a view.

Use:
SELECT CASE
WHEN T.option1 = ? THEN -1
WHEN T.option2 = ? THEN 0
ELSE 1
END AS field1
FROM Table1 AS T
I can't get your original TSQL to work - I get:
Msg 4145, Level 15, State 1, Line 4
An expression of non-boolean type specified in a context where a condition is expected, near 'THEN'.
...because there's no value evaluation. If you're checking if the columns are null, you'll need to use:
SELECT CASE
WHEN T.option1 IS NULL THEN -1
WHEN T.option2 IS NULL THEN 0
ELSE 1
END AS field1
FROM Table1 AS T
...or if you need when they are not null:
SELECT CASE
WHEN T.option1 IS NOT NULL THEN -1
WHEN T.option2 IS NOT NULL THEN 0
ELSE 1
END AS field1
FROM Table1 AS T
CASE expressions shortcircuit - if the first WHEN matches, it returns the value & exits handling for that row - so the options afterwards aren't considered.

If I remember correctly, PL/SQL also supports the case. You just would have to move the column alias from "field1=" before the expression to "AS filed1" after the expression.

SELECT..CASE - Refactor T-SQL

Can I refactor the below SQL CASE statements into single for each case ?
SELECT
CASE RDV.DOMAIN_CODE WHEN 'L' THEN CN.FAMILY_NAME ELSE NULL END AS [LEGAL_FAMILY_NAME],
CASE RDV.DOMAIN_CODE WHEN 'L' THEN CN.GIVEN_NAME ELSE NULL END AS [LEGAL_GIVEN_NAME],
CASE RDV.DOMAIN_CODE WHEN 'L' THEN CN.MIDDLE_NAMES ELSE NULL END AS [LEGAL_MIDDLE_NAMES],
CASE RDV.DOMAIN_CODE WHEN 'L' THEN CN.NAME_TITLE ELSE NULL END AS [LEGAL_NAME_TITLE],
CASE RDV.DOMAIN_CODE WHEN 'P' THEN CN.FAMILY_NAME ELSE NULL END AS [PREFERRED_FAMILY_NAME],
CASE RDV.DOMAIN_CODE WHEN 'P' THEN CN.GIVEN_NAME ELSE NULL END AS [PREFERRED_GIVEN_NAME],
CASE RDV.DOMAIN_CODE WHEN 'P' THEN CN.MIDDLE_NAMES ELSE NULL END AS [PREFERRED_MIDDLE_NAMES],
CASE RDV.DOMAIN_CODE WHEN 'P' THEN CN.NAME_TITLE ELSE NULL END AS [PREFERRED_NAME_TITLE]
FROM dbo.CLIENT_NAME CN
JOIN dbo.REFERENCE_DOMAIN_VALUE RDV
ON CN.NAME_TYPE_CODE = RDV.DOMAIN_CODE AND RDV.REFERENCE_DOMAIN_ID = '7966'

No, you will require 8 separate statements as case and other such variants can only be used in a select to modify the results of a single column, not a series of columns.

If RDV.DOMAIN_COD can only by 'P' or 'L' use NULLIf. It's cleaner.
NULLIF ( expression , expression )
NULLIF is equivalent to a searched CASE expression in which the two expressions are equal and the resulting expression is NULL.
SELECT
NullIf('P', RDV.DOMAIN_CODE) AS [LEGAL_FAMILY_NAME],
...
NullIf('L', RDV.DOMAIN_CODE) AS [PREFERRED_FAMILY_NAME],
...

Since a CASE expression returns a single value, you cannot take eight CASE expressions returning 8 values and make a single CASE expression that returns all eight.

A less efficient alternative with no cases:
SELECT LEGAL_FAMILY_NAME, LEGAL_GIVEN_NAME, LEGAL_MIDDLE_NAMES, LEGAL_NAME_TITLE,
PREFERRED_FAMILY_NAME, PREFERRED_GIVEN_NAME, PREFERRED_MIDDLE_NAMES, PREFERRED_NAME_TITLE
FROM dbo.REFERENCE_DOMAIN_VALUE RDV
LEFT OUTER JOIN
( SELECT
NAME_TYPE_CODE,
FAMILY_NAME AS [LEGAL_FAMILY_NAME],
GIVEN_NAME AS [LEGAL_GIVEN_NAME],
MIDDLE_NAMES AS [LEGAL_MIDDLE_NAMES],
NAME_TITLE AS [LEGAL_NAME_TITLE]
FROM dbo.CLIENT_NAME
WHERE NAME_TYPE_CODE = 'L') LN ON RDV.DOMAIN_CODE = LN.NAME_TYPE_CODE
LEFT OUTER JOIN
( SELECT
NAME_TYPE_CODE,
FAMILY_NAME AS [PREFERRED_FAMILY_NAME],
GIVEN_NAME AS [PREFERRED_GIVEN_NAME],
MIDDLE_NAMES AS [PREFERRED_MIDDLE_NAMES],
NAME_TITLE AS [PREFERRED_NAME_TITLE]
FROM dbo.CLIENT_NAME
WHERE NAME_TYPE_CODE = 'P') PN ON RDV.DOMAIN_CODE = PN.NAME_TYPE_CODE
WHERE RDV.REFERENCE_DOMAIN_ID = '7966'
You could also use a temp table or table variable with all 8 columns and then do two inserts. You could also use a UNION ALL. My guess is that the 8 case statements are the most efficient way. This is especially true if you have some key where you will want some type of ClientID, Legal Names, Preferred Names so you will wrap a MAX around the cases or something and group by a ClientID......
You could generate the SQL script using syscols/INFORMATION_SCHEMA.columns with two case whens for each column 'CASE WHEN DOMAIN_CODE = ''P'' THEN ' + COLUMN_NAME + ' ELSE NULL END AS PREFERRED_' + COLUMN_NAME and then another for L. You could make a LOOP so that the same code executes once for P and once for L and get it down to one loop. Then you could EXEC the string directly, or PRINT it and put it into your SQL script. Anyway for just 8 columns I would cut/paste the case statements...
But anyway in general T-SQL is limited on being able to do for eaches over columns. Either you generate the script using a code generator (done in t-sql or another programming language) or you rethink your problem in another way. But many times you get better performance from duplicate cut/paste code. And many times it isn't worth the hassle of writing an external code generator (ie just for 8 case statements).