Say I have this
col_1 | col_2
------------
1 | a
1 | b
1 | c
2 | d
2 | e
I want result like this
col_1 | col_2_concat
-------------------
1 | a,b,c
2 | d,e
something like this I would guess:
select
col_1,
join_by_comma(col2)
from tbl
group by col_1
I think you need something like:
WITH x AS (
SELECT
'a' AS c,
'b' AS c2
UNION ALL
SELECT
'a',
'b2'
UNION ALL
SELECT
'a2',
'b3'
UNION ALL
SELECT
'a2',
'b4'
)
SELECT
c,
ARRAY_JOIN(ARRAY_AGG(c2), ',') as c2
FROM x
GROUP BY
c
I have a table TABLEA that store data in a Columns which are basically multilist columns like this ColumnA ',2562,2563,2564,' and ColumnB with values ',121,122,123,'.
These column are actually foreign key values coming from another table.
Data is something like this in Table A.
ID NAME ColumnA ColumnB
1 ITEM1 ,2562,2563,2564, ,121,122,123
2 ITEM2 NULL ,6455,545,
3 ITEM3 ,1221,1546, NULL
4 ITEM4 NULL NULL
I want to join these columns with there parent tables and extract data.
I am hoping the result set would have 8 rows.
For example
ITEM ColumnA ColumB
ITEM1 2562 121
ITEM1 2563 122
ITEM1 2564 123
ITEM2 NULL 6455
ITEM2 NULL 545
....
I have tried this query with some help but this is not working when I try to use ColumnB as well and also it ignores the Items with NULL values.
The Column A is saving Ids of USER_GROUP table but ColumnB is fetching the Ids from some other table lets say GROUP1 and there could be another Column ColumnC that might be storing values from another table so that's kind of situation I am stuck in and hope I have explained so someone can understand but I am open if you want me to improve more
SELECT ug.*
FROM USER_GROUP ug
WHERE EXISTS (SELECT 1
FROM TableA t1
WHERE t1.COLUMNA LIKE '%,' || ug.ID || ',%'
)
AND EXISTS (SELECT 1
FROM TableA t1
WHERE t1.COLUMNB LIKE '%,' || ug.ID || ',%'
);
Here's one option:
SQL> with test (id, name, cola, colb) as
2 (select 1, 'item1', ',2562,2563,2564,', ',121,122,123,' from dual union all
3 select 2, 'item2', null , ',6455,545,' from dual union all
4 select 3, 'item3', ',1221,1546,' , null from dual union all
5 select 4, 'item4', null , null from dual
6 ),
7 remcom
8 -- remove leading and trailing commas
9 as (select id,
10 name,
11 rtrim(ltrim(cola, ','), ',') cola,
12 rtrim(ltrim(colb, ','), ',') colb
13 from test
14 )
15 select id,
16 name,
17 regexp_substr(cola, '[^,]+', 1, column_value) cola,
18 regexp_substr(colb, '[^,]+', 1, column_value) colb
19 from remcom r cross join
20 table(cast(multiset(select level from dual
21 connect by level <= regexp_count(nvl(r.cola, r.colb), ',') + 1
22 ) as sys.odcinumberlist))
23 order by id, name, cola, colb;
ID NAME COLA COLB
---------- ----- ---------- ----------
1 item1 2562 121
1 item1 2563 122
1 item1 2564 123
2 item2 545
2 item2 6455
3 item3 1221
3 item3 1546
4 item4
8 rows selected.
SQL>
Now that you have it, join this result with another table you have.
By the way, this example nicely shows what it is a bad idea to store multiple values into the same column. Don't do that.
You don't need to use (slow) regular expressions and can do it with simple string functions in a recursive sub-query factoring clause:
WITH split_data ( id, name, columna, columnb, starta, enda, startb, endb ) AS (
SELECT id,
name,
columna,
columnb,
INSTR(columna,',',1,1),
INSTR(columna,',',1,2),
INSTR(columnb,',',1,1),
INSTR(columnb,',',1,2)
FROM test_data
UNION ALL
SELECT id,
name,
columna,
columnb,
enda,
CASE WHEN enda = 0 THEN 0 ELSE INSTR(columna,',',enda+1,1) END,
endb,
CASE WHEN endb = 0 THEN 0 ELSE INSTR(columnb,',',endb+1,1) END
FROM split_data
WHERE enda > 0
OR endb > 0
)
SELECT id,
name,
CASE
WHEN starta = 0 THEN NULL
WHEN enda = 0 THEN SUBSTR( columna, starta + 1 )
ELSE SUBSTR( columna, starta + 1, enda - starta - 1 )
END AS valuea,
CASE
WHEN startb = 0 THEN NULL
WHEN endb = 0 THEN SUBSTR( columnb, startb + 1 )
ELSE SUBSTR( columnb, startb + 1, endb - startb - 1 )
END as valueb
FROM split_data
ORDER BY id, starta, startb;
Which for your test data:
CREATE TABLE test_data ( ID, NAME, ColumnA, ColumnB ) AS
SELECT 1, 'ITEM1', ',2562,2563,2564', ',121,122,123' FROM DUAL UNION ALL
SELECT 2, 'ITEM2', NULL, ',6455,545' FROM DUAL UNION ALL
SELECT 3, 'ITEM3', ',1221,1546', NULL FROM DUAL UNION ALL
SELECT 4, 'ITEM4', NULL, NULL FROM DUAL;
Outputs:
ID | NAME | VALUEA | VALUEB
-: | :---- | :----- | :-----
1 | ITEM1 | 2562 | 121
1 | ITEM1 | 2563 | 122
1 | ITEM1 | 2564 | 123
2 | ITEM2 | null | 6455
2 | ITEM2 | null | 545
3 | ITEM3 | 1221 | null
3 | ITEM3 | 1546 | null
4 | ITEM4 | null | null
db<>fiddle here
I would like to gradually aggregate a string column in Oracle sql.
From this table:
col_1 | col_2
-------------
1 | A
1 | B
1 | C
2 | C
2 | D
to:
col_1 | col_2
-------------
1 | A
1 | A,B
1 | A,B,C
2 | C
2 | C,D
I tried LISTAGG but it won't return all rows due to group by. I have about 2 million rows in the table.
Oracle doesn't support accumulating string concatenation with a single listagg() expression. However, you can use a subquery.
Just one note: SQL tables represent unordered sets. You seem to have an ordering in mind. The following code adds an ordering column:
with t as (
select 1 as id, 1 as x, 'A' as y from dual union all
select 2, 1 as x, 'B' as y from dual union all
select 3, 1 as x, 'C' as y from dual union all
select 4, 2 as x, 'C' as y from dual union all
select 5, 2 as x, 'D' as y from dual
)
select t.*,
(select listagg(t2.y, ',') within group (order by t2.id)
from t t2
where t2.x = t.x and t2.id <= t.id
)
from t;
A hierarchical query option looks like this:
SQL> with t as (
2 select 1 as id, 1 as x, 'A' as y from dual union all
3 select 2, 1 as x, 'B' as y from dual union all
4 select 3, 1 as x, 'C' as y from dual union all
5 select 4, 2 as x, 'C' as y from dual union all
6 select 5, 2 as x, 'D' as y from dual
7 )
8 select x,
9 ltrim(sys_connect_by_path(y, ','), ',') result
10 from (select x,
11 y,
12 row_number() over (partition by x order by y) rn
13 from t
14 )
15 start with rn = 1
16 connect by prior rn = rn - 1 and prior x = x;
X RESULT
---------- --------------------
1 A
1 A,B
1 A,B,C
2 C
2 C,D
SQL>
I have a table in postgres like below
I want an sql in postgres that count a combination of 2 columns that has YY
Expecting an output like
Combination Count
AB 2
AC 1
AD 2
AZ 1
BC 1
BD 3
BZ 2
CD 2
CZ 0
DZ 1
Can anyone help me?
WITH stacked AS (
SELECT id
, unnest(array['A', 'B', 'C', 'D', 'Z']) AS col_name
, unnest(array[a, b, c, d, z]) AS col_value
FROM test t
)
SELECT combo, sum(cnt) AS count
FROM (
SELECT t1.id, t1.col_name || t2.col_name AS combo
, (CASE WHEN t1.col_value = 'Y' AND t2.col_value = 'Y' THEN 1 ELSE 0 END) AS cnt
FROM stacked t1
INNER JOIN stacked t2
ON t1.id = t2.id
AND t1.col_name < t2.col_name) t3
GROUP BY combo
ORDER BY combo
yields
| combo | count |
|-------+-------|
| AB | 2 |
| AC | 1 |
| AD | 2 |
| AZ | 2 |
| BC | 1 |
| BD | 3 |
| BZ | 2 |
| CD | 2 |
| CZ | 0 |
| DZ | 1 |
The unnesting recipe for unpivoting the table comes from Stew's post, here.
To count occurrances of YYY among 3 columns you could use:
WITH stacked AS (
SELECT id
, unnest(array['A', 'B', 'C', 'D', 'Z']) AS col_name
, unnest(array[a, b, c, d, z]) AS col_value
FROM test t
)
SELECT combo, sum(cnt) AS count
FROM (
SELECT t1.id, t1.col_name || t2.col_name || t3.col_name AS combo
, (CASE WHEN t1.col_value = 'Y'
AND t2.col_value = 'Y'
AND t3.col_value = 'Y' THEN 1 ELSE 0 END) AS cnt
FROM stacked t1
INNER JOIN stacked t2
ON t1.id = t2.id
INNER JOIN stacked t3
ON t1.id = t3.id
AND t1.col_name < t2.col_name
And t2.col_name < t3.col_name
) t3
GROUP BY combo
ORDER BY combo
;
which yields
| combo | count |
|-------+-------|
| ABC | 0 |
| ABD | 1 |
| ABZ | 2 |
| ACD | 1 |
| ACZ | 0 |
| ADZ | 1 |
| BCD | 1 |
| BCZ | 0 |
| BDZ | 1 |
| CDZ | 0 |
Or, to handle combinations of N columns, you could use WITH RECURSIVE:
For example, for N = 3,
WITH RECURSIVE result AS (
WITH stacked AS (
SELECT id
, unnest(array['A', 'B', 'C', 'D', 'Z']) AS col_name
, unnest(array[a, b, c, d, z]) AS col_value
FROM test t)
SELECT id, array[col_name] AS path, array[col_value] AS path_val, col_name AS last_name
FROM stacked
UNION
SELECT r.id, path || s.col_name, path_val || s.col_value, s.col_name
FROM result r
INNER JOIN stacked s
ON r.id = s.id
AND s.col_name > r.last_name
WHERE array_length(r.path, 1) < 3) -- Change 3 to your value for N
SELECT combo, sum(cnt)
FROM (
SELECT id, array_to_string(path, '') AS combo, (CASE WHEN 'Y' = all(path_val) THEN 1 ELSE 0 END) AS cnt
FROM result
WHERE array_length(path, 1) = 3) t -- Change 3 to your value for N
GROUP BY combo
ORDER BY combo
Note that N = 3 is used in 2 places in the SQL above.
I would do this using a lateral join:
with vals as (
select v.*
from t cross join lateral
(values ('A', A), ('B', B), ('C', C), ('D', D), ('Z', Z)
) v(which, val)
)
select (v1.which || v2.which) as combo,
sum( (val = 'Y')::int ) as count
from vals v1 join
vals v2
on v1.which < v2.which
group by combo
order by combo;
I consider lateral joins to be a more direct way to unpivot the values. There is no need to convert the values to an array an unnest, much less unnest two arrays and align the values.
There is a group as below.
refno | col1 | col2
---------------------
1 | a | aa
1 | b | bb
1 | c | cc
1 | d | dd
I want to make it like this using Oracle SQL:
refno a b c d
1 aa bb cc dd
How to do it?
You can do it using PIVOT
WITH sel AS
(SELECT 1 refno , 'a' col1 , 'aa' col2 FROM dual
UNION ALL
SELECT 1 , 'b' , 'bb' FROM dual
UNION ALL
SELECT 1 , 'c' , 'cc' FROM dual
UNION ALL
SELECT 1 , 'd' , 'dd' FROM dual
)
SELECT *
FROM sel
PIVOT
(max(col2)
FOR col1 IN ('a','b','c','d'))
But you have to specify col1 values manually - FOR col1 IN ('a','b','c','d')
More - here and here