Is it possible to build a select query that sums up value of a column and also get the fields from the column of the same table, and an example please . I am new to DB2 and still learning.
I tried using the below,
SELECT SUM(Column containing numbers)
,Column 2
FROM Table
but this gives me a SQL return code of -122
It's possible with the SUM olap function.
SELECT
SUM(C1) OVER () AS C1_SUM
, C2
FROM
(
SELECT 1, 'A' FROM SYSIBM.SYSDUMMY1
UNION ALL SELECT 2, 'B' FROM SYSIBM.SYSDUMMY1
) T (C1, C2)
C1_SUM
C2
3
B
3
A
fiddle
Related
I have a case driven query . Below is the simplest form
select Column 1 from mytable
Results :
Column 1
latinnametest
LatinManual
LatinAuto
Is it possible to show the aggregated data of column 1 data of all the resulted rows in another Column say column 5 in front of each row with comma separated ?
Expected :
Column 1 Column 2
latinnametest latinnametest,LatinManual,LatinAuto
LatinManual latinnametest,LatinManual,LatinAuto
LatinAuto latinnametest,LatinManual,LatinAuto
I have used array_agg and concat() but it aggregates the same row data in column 2 but not as expected to add all rows column data comma separated . Any help please.
Edit :
I have tried the solution mentioned below but I am getting repetitive data in the column . see the screenshot. I have hover the mouse over that last column and see the repetitive data . Any solution to this ?
[![enter image description here][1]][1]
You can use string_agg() as a window function:
select column_1,
string_agg(column_1, ',') over () as all_values
from the_table;
Edit, after the scope was changed:
If you need distinct values, use a derived table:
select column_1,
string_agg(column_1, ',') over () as all_values
from (
select distinct column_1
from the_table
) t;
Alternatively with a common table expression:
with vals as (
select string_agg(distinct column_1, ',') as all_values
from the_table
)
select t.column_1, v.all_values
from the_table t
cross join vals v
For example, where the element is 'hi', and where N is 3, I need a PostgreSQL snippet I can use in a SELECT query that returns the following array:
['hi', 'hi', 'hi']
Postgres provides array_fill for this purpose, e.g.:
SELECT array_fill('hi'::text, '{3}');
SELECT array_fill('hi'::text, array[3]);
The two examples are equivalent but the 2nd form is more convenient if you wish to replace the dimension 3 with a variable.
See also: https://www.postgresql.org/docs/current/functions-array.html
You may use array_agg with generate_series
select array_agg(s) from ( values('hi')) as t(s) cross join generate_series(1,3)
Generic
select array_agg(s) from ( values(:elem)) as t(s) cross join generate_series(1,:n)
DEMO
sql demo
with cte as (
select 'hi' as rep_word, generate_series(1, 3) as value
) -- ^^^ n = 3
select array(SELECT rep_word::text from cte);
I'm trying to create a table with the following columns:
I want to use a with recursive table to do this. The following code however is giving the following error:
'ERROR: column "b" does not exist'
WITH recursive numbers AS
(
SELECT 1,2,4 AS a, b, c
UNION ALL
SELECT a+1, b+1, c+1
FROM Numbers
WHERE a + 1 <= 10
)
SELECT * FROM numbers;
I'm stuck because when I just include one column this works perfectly. Why is there an error for multiple columns?
This appears to be a simple syntax issue: You are aliasing the columns incorrectly. (SELECT 1,2,4 AS a, b, c) is incorrect. Your attempt has 5 columns: 1,2,a,b,c
Break it down to just: Select 1,2,4 as a,b,c and you see the error but Select 1 a,2 b,4 c works fine.
b is unknown in the base select because it is being interpreted as a field name; yet no table exists having that field. Additionally the union would fail as you have 5 fields in the base and 3 in the recursive union.
DEMO: http://rextester.com/IUWJ67486
One can define the columns outside the select making it easier to manage or change names.
WITH recursive numbers (a,b,c) AS
(
SELECT 1,2,4
UNION ALL
SELECT a+1, b+1, c+1
FROM Numbers
WHERE a + 1 <= 10
)
SELECT * FROM numbers;
or this approach which aliases the fields internally so the 1st select column's names would be used. (a,b,c) vs somereallylongalias... in union query. It should be noted that not only the name of the column originates from the 1st query in the unioned sets; but also the datatype for the column; which, must match between the two queries.
WITH recursive numbers AS
(
SELECT 1 as a ,2 as b,4 as c
UNION ALL
SELECT a+1 someReallyLongAlias
, b+1 someReallyLongAliasAgain
, c+1 someReallyLongAliasYetAgain
FROM Numbers
WHERE a<5
)
SELECT * FROM numbers;
Lastly, If you truly want to stop at 5 then the where clause should be WHERE a < 5. The image depicts this whereas the query does not; so not sure what your end game is here.
having a sql e.g. something like the following resulting in some rows with one value.
I search a different sql than SELECT * FROM some_sql which results in one row with comma separated values.
WITH some_sql AS (
SELECT 1 FROM DUAL
UNION
SELECT 2 FROM DUAL
)
SELECT * FROM some_sql
this SQL results in the two rows with value 1 and 2.
I seach a SQl resulting in 1,2 without changing the code of 'some_sql'.
Consider http://halisway.blogspot.com/2006/08/oracle-groupconcat-updated-again.html
Sice you are on 11G you can use LISTAGG
WITH some_sql AS (
SELECT 1 x FROM DUAL
UNION
SELECT 2 x FROM DUAL
)
SELECT LISTAGG(x, ',') WITHIN GROUP(ORDER BY x) FROM some_sql
In Postgre, why does
select abc from (select 1) as abc
produces:
(1)
and
select * from (select 1) as abc
produces:
1
That's really strange to me. Is that the case with MySQL, Oracle, etc?
I spent hours figuring out why my conditions were failing...
The rows returned by your queries have different type: the first one is ROW(INT), while the second one is INT.
MySQL and others lack this feature.
In your first query, you are selecting a whole ROW as a single column. This query
SELECT abc FROM (SELECT 1, 2) abc
will produce (1, 2), which is a single column too and has type ROW.
To select the INT value, use:
SELECT abc.col
FROM (
SELECT 1 AS col
) abc