How would I go about converting this into a user defined function? Also, I know there are several types of UDFs... which one would be best in this case? Thank you for the help.
SELECT TOP 10 ParkingSpotNumber
, count(*) as 'Usage'
FROM ParkingTransaction
GROUP BY ParkingSpotNumber
ORDER BY 'Usage' DESC
Since you are returning more than one column and you want this to be a function, then you can use a Table-Valued Function:
create function Top_Parking_usage()
returns #ParkingCount table
(
ParkingSpotNumber int not null,
UsageCount int not null
)
as
BEGIN
INSERT INTO #ParkingCount(ParkingSpotNumber, UsageCount)
SELECT TOP 10 ParkingSpotNumber
, count(*) as 'Usage'
FROM ParkingTransaction
GROUP BY ParkingSpotNumber
ORDER BY 'Usage' DESC
RETURN
END;
GO
Then when you call it, you will use:
select *
from dbo.Top_Parking_usage()
See SQL Fiddle with Demo
Try the below..... it returns the table...
CREATE FUNCTION udf_GetParkingInfo()
RETURNS TABLE
AS
RETURN
(
SELECT TOP 10 ParkingSpotNumber
, count(*) as 'Usage'
FROM ParkingTransaction
GROUP BY ParkingSpotNumber
ORDER BY 'Usage' DESC
);
SELECT * from udf_GetParkingInfo()
Related
I have a select query return and it shows the result like below:
select * from table gives the result like below
I have parameter called Apple If I pass the parameter somewhere in query I should get the result like below
How to get this in postgresql. If anyone knows please share the answer below.
I would do this with a helper function for clarity. And it might be reusable.
create or replace function filter_jsonb_array(arr jsonb, fruit text)
returns jsonb language sql immutable as
$$
select coalesce
(
(select jsonb_agg(j) from jsonb_array_elements(arr) j where j ->> 'fruit' = fruit),
'[]'::jsonb
);
$$;
and then
select "Column_A", "Column_B", filter_jsonb_array("Column_JSONARRAY", 'Apple') from table_;
If you do not want a function then the function body can be placed directly into the select query.
select
"Column_A",
"Column_B",
coalesce
(
(select jsonb_agg(j) from jsonb_array_elements("Column_JSONARRAY") j where j ->> 'fruit' = 'Apple'),
'[]'::jsonb
) "Column_JSONARRAY"
from table_;
Considering your datatype of column Column_JSONARRAY is JSONB, try This:
with cte as (
SELECT column_a, column_b, (column_jsonarray ->> ( index_-1 )::int)::jsonb AS "column_jsonarray"
FROM table_
CROSS JOIN jsonb_array_elements(column_jsonarray)
WITH ORDINALITY arr(array_,index_)
WHERE array_->>'fruit' in ('Apple')
)
select t1.column_a, t1.column_b, jsonb_agg(t2.column_jsonarray)
from table_ t1
left join cte t2 on t1.column_a =t2.column_a and t1.column_b =t2.column_b
group by t1.column_a, t1.column_b
I have a simple data set that looks like this:
Name Code
A A-One
A A-Two
B B-One
C C-One
C C-Two
C C-Three
I want to output it so it looks like this:
Name Code1 Code2 Code3 Code4 Code...n ...
A A-One A-Two
B B-One
C C-One C-Two C-Three
For each of the 'Name' values, there can be an undetermined number of 'Code' values.
I have been looking at various examples of Pivot SQL [including simple Pivot sql and sql using the XML function?] but I have not been able to figure this out - or to understand if it is even possible.
I would appreciate any help or pointers.
Thanks!
Try it like this:
DECLARE #tbl TABLE([Name] VARCHAR(100),Code VARCHAR(100));
INSERT INTO #tbl VALUES
('A','A-One')
,('A','A-Two')
,('B','B-One')
,('C','C-One')
,('C','C-Two')
,('C','C-Three');
SELECT p.*
FROM
(
SELECT *
,CONCAT('Code',ROW_NUMBER() OVER(PARTITION BY [Name] ORDER BY Code)) AS ColumnName
FROM #tbl
)t
PIVOT
(
MAX(Code) FOR ColumnName IN (Code1,Code2,Code3,Code4,Code5 /*add as many as you need*/)
)p;
This line
,CONCAT('Code',ROW_NUMBER() OVER(PARTITION BY [Name] ORDER BY Code)) AS ColumnName
will use a partitioned ROW_NUMBER in order to create numbered column names per code. The rest is simple PIVOT...
UPDATE: A dynamic approach to reflect the max amount of codes per group
CREATE TABLE TblTest([Name] VARCHAR(100),Code VARCHAR(100));
INSERT INTO TblTest VALUES
('A','A-One')
,('A','A-Two')
,('B','B-One')
,('C','C-One')
,('C','C-Two')
,('C','C-Three');
DECLARE #cols VARCHAR(MAX);
WITH GetMaxCount(mc) AS(SELECT TOP 1 COUNT([Code]) FROM TblTest GROUP BY [Name] ORDER BY COUNT([Code]) DESC)
SELECT #cols=STUFF(
(
SELECT CONCAT(',Code',Nmbr)
FROM
(SELECT TOP((SELECT mc FROM GetMaxCount)) ROW_NUMBER() OVER(ORDER BY (SELECT NULL)) FROM master..spt_values) t(Nmbr)
FOR XML PATH('')
),1,1,'');
DECLARE #sql VARCHAR(MAX)=
'SELECT p.*
FROM
(
SELECT *
,CONCAT(''Code'',ROW_NUMBER() OVER(PARTITION BY [Name] ORDER BY Code)) AS ColumnName
FROM TblTest
)t
PIVOT
(
MAX(Code) FOR ColumnName IN (' + #cols + ')
)p;';
EXEC(#sql);
GO
DROP TABLE TblTest;
As you can see, the only part which will change in order to reflect the actual amount of columns is the list in PIVOTs IN() clause.
You can create a string, which looks like Code1,Code2,Code3,...CodeN and build the statement dynamically. This can be triggered with EXEC().
I'd prefer the first approach. Dynamically created SQL is very mighty, but can be a pain in the neck too...
I've got a table with a lot of columns in it and I want to run a query to find the most common value in each column.
Ordinarily for a single column, I'd run something like:
SELECT country
FROM users
GROUP BY country
ORDER BY count(*) DESC
LIMIT 1
Does PostgreSQL have a built in function for doing this or can anyone suggest a query I could run to achieve this?
Using the same query, for more than one column you should do:
SELECT *
FROM
(
SELECT country
FROM users
GROUP BY 1
ORDER BY count(*) DESC
LIMIT 1
) country
,(
SELECT city
FROM users
GROUP BY 1
ORDER BY count(*) DESC
LIMIT 1
) city
This works for any type and will return all the values in the same row, with the columns having its original name.
For more columns just had more subquerys as:
,(
SELECT someOtherColumn
FROM users
GROUP BY 1
ORDER BY count(*) DESC
LIMIT 1
) someOtherColumn
Edit:
You could reach it with window functions also. However it will not be better in performance nor in readability.
Starting from PG 9.4 there is aggregate function for this:
mode() WITHIN GROUP (ORDER BY sort_expression)
returns the most frequent input value (arbitrarily choosing the first one if there are multiple equally-frequent results)
And for earlier versions, you could create one...
CREATE OR REPLACE FUNCTION mode_array(anyarray)
RETURNS anyelement AS
$BODY$
SELECT a FROM unnest($1) a GROUP BY 1 ORDER BY COUNT(1) DESC, 1 LIMIT 1;
$BODY$
LANGUAGE SQL IMMUTABLE;
CREATE AGGREGATE mode(anyelement)(
SFUNC = array_append, --Function to call for each row. Just builds the array
STYPE = anyarray,
FINALFUNC = mode_array, --Function to call after everything has been added to array
INITCOND = '{}'--Initialize an empty array when starting
) ;
Usage: SELECT mode(column) FROM table;
If I were doing this, I'd write a query like this one:
SELECT 'country', country
FROM users
GROUP BY country
ORDER BY count(*) DESC
LIMIT 1
UNION ALL
SELECT 'city', city
FROM USERS
GROUP BY city
ORDER BY count(*) DESC
LIMIT 1
-- etc.
It should be noted this only works if all the columns are of compatible types. If they are not, you'll probably need a different solution.
This window function version will read the users table and the computed table once each. The correlated subquery version will read the users table once for each of the columns. If the columns are many as in the OPs case then my guess is that this is faster. SQL Fiddle
select distinct on (country_count, age_count) *
from (
select
country,
count(*) over(partition by country) as country_count,
age,
count(*) over(partition by age) as age_count
from users
) s
order by country_count desc, age_count desc
limit 1
HERE IS THE FUNCTION:
ALTER FUNCTION dbo.FN_GET_QUARTER
-- the parameters for the function here
(
#FN_Qtr_date datetime
)
RETURNS INT
AS
BEGIN
RETURN datepart(qq,#FN_Qtr_date)
END
HERE IS THE SQL REPORT:
IF(SELECT(OBJECT_ID('TEMPDB..#T1'))) IS NOT NULL DROP TABLE #T1
SELECT L_NUMBER, LAST_MAINTENANCE_DATE,
dbo.FN_FICO_BANDS (LAST_MAINTENANCE_DATE) AS FN_Qtr_date
INTO #T1
FROM OPENQUERY(SrvLink, '
SELECT LOAN_NUMBER,LAST_MAINTENANCE_DATE
FROM BDE.loan_V
FETCH FIRST 1000 ROWS ONLY WITH UR ')
GO
SELECT COUNT(*), FN_Qtr_date
FROM #T1
GROUP BY FN_Qtr_date
ORDER BY FN_Qtr_date
Results:
L count FN_Qtr_Date
150 Invalid
355 Invalid
I am not sure what I am doing wrong..
The first thing that jumps out at me is that you're calling dbo.FN_FICO_BANDS instead of dbo.FN_GET_QUARTER
dbo.FN_FICO_BANDS (LAST_MAINTENANCE_DATE) AS FN_Qtr_date
If you're going to use the function on LAST_MAINTENANCE_DATE, you need to use:
dbo.FN_Qtr_Date(LAST_MAINTENANCE_DATE) AS YourQuarter
I'm trying to build a stored procedure that makes use of another stored procedure. Taking its result and using it as part of its where clause, from some reason I receive an error:
Invalid object name 'dbo.GetSuitableCategories'.
Here is a copy of the code:
select distinct top 6 * from
(
SELECT TOP 100 *
FROM [dbo].[products] products
where products.categoryId in
(select top 10 categories.categoryid from
[dbo].[GetSuitableCategories]
(
-- #Age
-- ,#Sex
-- ,#Event
1,
1,
1
) categories
ORDER BY NEWID()
)
--and products.Price <=#priceRange
ORDER BY NEWID()
)as d
union
select * from
(
select TOP 1 * FROM [dbo].[products] competingproducts
where competingproducts.categoryId =-2
--and competingproducts.Price <=#priceRange
ORDER BY NEWID()
) as d
and here is [dbo].[GetSuitableCategories] :
if (#gender =0)
begin
select * from categoryTable categories
where categories.gender =3
end
else
begin
select * from categoryTable categories
where categories.gender = #gender
or categories.gender =3
end
I would use an inline table valued user defined function. Or simply code it inline is no re-use is required
CREATE dbo.GetSuitableCategories
(
--parameters
)
RETURNS TABLE
AS
RETURN (
select * from categoryTable categories
where categories.gender IN (3, #gender)
)
Some points though:
I assume categoryTable has no gender = 0
Do you have 3 genders in your categoryTable? :-)
Why do pass in 3 parameters but only use 1? See below please
Does #sex map to #gender?
If you have extra processing on the 3 parameters, then you'll need a multi statement table valued functions but beware these can be slow
You can't use the results of a stored procedure directly in a select statement
You'll either have to output the results into a temp table, or make the sproc into a table valued function to do what you doing.
I think this is valid, but I'm doing this from memory
create table #tmp (blah, blah)
Insert into #tmp
exec dbo.sprocName