I have 2 rows
code name
1 cake
2 chocolate
This query give me both results
select * from table a where a.code=2 or a.code =1
If one of these records doesn't show, I don't want to retrieve anything.
select * from table a where a.code=2 or a.code =1
and exists ( select 1 from table b where a.code=b.code )
You can use an analytic function:
SELECT code,
name
FROM (
SELECT a.*,
COUNT(DISTINCT code) OVER () AS num_codes
FROM table_name a
WHERE a.code IN (1,2)
)
WHERE num_codes = 2;
Which, for the sample data:
CREATE TABLE table_name (code, name) AS
SELECT 1, 'cake' FROM DUAL UNION ALL
SELECT 2, 'chocolate' FROM DUAL;
Outputs:
CODE
NAME
1
cake
2
chocolate
If you:
DELETE FROM table_name WHERE code = 1;
And run the query again, it outputs:
CODE
NAME
db<>fiddle here
Simple check the count distict
select * from tab1
where code in (1,2)
and (select count(distinct code) from tab1 where code in (1,2)) = 2;
If you want to discard the case where the table has duplicated rows, e.g. 1,1,2
add an other predicate filter
and (select count(*) from tab1 where code in (1,2)) = 2
Related
I need the count of this:
select distinct ID
from (
select ID from A
union all
select ID from B
union all
select ID from C
) ids
GROUP BY ID HAVING COUNT(*) > 1;
but I have no idea how to do it.
Use a subquery:
select count(*)
from (select ID
from (select ID from A
union all
select ID from B
union all
select ID from C
) ids
group by ID
having count(*) > 1
) i;
SELECT DISTINCT is almost never needed with GROUP BY and definitely not in this case.
You just want to find the id that appear 2 more times in the A,B,C table, the SQL is below:
select count(1) from (
select
id,
count(1)
from
(
select ID from A
union all
select ID from B
union all
select ID from C
)
group by id having(count(1)>1)
) tmp
After query table A using first query, I have these records:
pID cID code
1 1 A
1 1 B
1 1 B
1 1 B
After query table B using second query, I have one record:
pID cID code
1 1 B
1 1 B
I want table A exclude the records of table B. The result is:
pID cID code
1 1 A
1 1 A
How can I do that? Hope u could help me. thanks.
Updating...
Sorry for the example to make you confuse
If I got these record from second table:
pID cID code
1 1 B
Then the result I want is (exclude one record):
pID cID code
1 1 A
1 1 B
1 1 B
you try GROUP BY function in your Query
example :
select pID,cID,code from table group by code
using EXCEPT and row_number() to generate a unique no
;with cte1 as
(
select *, rn = row_number() over (partition by pID, cID, code order by pID, cID, code)
from query1
),
cte2 as
(
select *, rn = row_number() over (partition by pID, cID, code order by pID, cID, code)
from query2
)
select *
from cte1
except
select *
from cte2
Based on your question, which I think you want to delete the records from B which occur more than once in A:
first select all records from A which are not there in B and then union them 1 distinct records which are there in both A and B:
select * from A
except
select * from B
union all
select distinct *
from
(select a.pid, a.cid, a.code
from
A
inner join
B
on a.pid=b.pid and a.cid=b.cid and a.code=b.code)
Just use EXCEPT. How ever your desired output is wrong as 1 1 B also the same record from TableB
SELECT * FROM TABLE_A
EXCEPT
SELECT * FROM TABLE_B
Refer this Link
If your case NOt all But some then.
Simply you can use DISTINCT
As per the UPdate in Question (From what I understood)
SELECT DISTINCT * FROM TABLE_A
UNION ALL
SELECT * FROM TABLE_B
since I am not as good with more complex SQL SELECT Statements I thought of just asking here, since it's hard to find something right on topic.
I got two tables who have exactly the same structure like
TABLE A (id (INT(11)), time (VARCHAR(10));)
TABLE B (id (INT(11)), time (VARCHAR(10));)
Now I want a single SELECT to count the entrys of an specific id in both tables.
SELECT COUNT(*) FROM TABLE A WHERE id = '1';
SELECT COUNT(*) FROM TABLE B WHERE id = '1';
So I thought it would be much better for the database performance if I use one SELECT instead of one.
Thanks for helping out
SELECT COUNT(*) as count, 'tableA' as table_name FROM TABLEA WHERE id = '1'
union all
SELECT COUNT(*), 'tableB' FROM TABLEB WHERE id = '1'
If you want the separate counts in a single row, you can use subqueries
SELECT
(SELECT COUNT(*) FROM TABLE A WHERE id = '1') a_count,
(SELECT COUNT(*) FROM TABLE B WHERE id = '1') b_count;
You could do it like:
select count(*)
from (
select id from t1 where id = 1
union all
select id from t2 where id = 1
) as t
Another alternative is:
select sum(cnt)
from (
select count(*) as cnt from t1 where id = 1
union all
select count(*) as cnt from t2 where id = 1
) as t
I require to select a row if there is only one row exists, if there are more rows, it should select 0 rows.
If you're using PL/SQL, then selecting the column using select-into will throw a too_many_rows exception if there's more than one row returned:
declare
var table.column%type;
begin
select column
into var
from table
where ...;
end;
If you want to do this just using SQL, then you can do something like:
select *
from
(select s.*, count(*) over () c
from
(select *
from table
where ...
and rownum <= 2
) s
)
where c = 1
UPDATE
As DazzaL says in the comments, the reason for the rownum <= 2 restriction is to short-circuit the query if there's more than 2 rows in the result set. This can give significant performance benefits if the dataset is large.
I came up with this, just for the heck of it, using a CTE
With counter as
( select count(any_field) as cnt from your_query
)
SELECT
your_query
WHERE exists (SELECT cnt from Counter WHERE cnt=1)
1 row when there's 1 record - http://sqlfiddle.com/#!4/84c7b/2
0 rows when more than 1 rec - http://sqlfiddle.com/#!4/95c4a/1
EDIT
or if you want to avoid repeating the whole query... an example :
(using the schema from sqlfiddle http://sqlfiddle.com/#!4/6a2d8/117 )
With results as
( select * from montly_sales_totals
),
counter as
( SELECT count(name) as cnt FROM results
)
SELECT *
FROM results
WHERE exists (SELECT cnt from Counter WHERE cnt=5)
SELECT fld1, fld2
FROM (SELECT COUNT(*) over() cnt ,fld1, fld2 FROM tbl WHERE fld1 = 'key')
WHERE cnt = 1
I require to select a row if there is only one row exists, if there
are more rows, it should select 0 rows.
I assume the table contains only the row(s) you are interested to see (or not to see), in that case I would write something like
select *
from table1
where 1 = (select count(1)
from table1
)
In case you want to see only one row from a subset of results from your table, I would go for something like:
with t as ( select *
from table1
where [put here your condition]
)
select *
from t
where 1 = (select count(1)
from t
)
Try this:
SELECT f1,f2
FROM Table
WHERE (f1 = #f1) AND (f2=#f2) AND (f3=#f3)
GROUP BY f1,f2
HAVING (COUNT(*) = 1)
DECLARE COL_COUNT NUMBER;
BEGIN
COL_COUNT: = 0 ;
SELECT COUNT (1) INTO COL_COUNT FROM USER_TAB_COLUMNS WHERE TABLE_NAME = '(ur table name)';
IF COL_COUNT = 0 THEN
EXECUTE IMMEDIATE ('select * from dual') ;
END IF;
END;
Try this:
SELECT col1, col2 FROM
(SELECT count(id) as 'cnt', col1, col2 FROM table_name WHERE col1='value')
WHERE cnt=1;
I tried the sql query given below:
SELECT * FROM (SELECT *
FROM TABLE_A ORDER BY COLUMN_1)DUMMY_TABLE
UNION ALL
SELECT * FROM TABLE_B
It results in the following error:
The ORDER BY clause is invalid in views, inline functions, derived
tables, subqueries, and common table expressions, unless TOP or FOR
XML is also specified.
I need to use order by in union all. How do I accomplish this?
SELECT *
FROM
(
SELECT * FROM TABLE_A
UNION ALL
SELECT * FROM TABLE_B
) dum
-- ORDER BY .....
but if you want to have all records from Table_A on the top of the result list, the you can add user define value which you can use for ordering,
SELECT *
FROM
(
SELECT *, 1 sortby FROM TABLE_A
UNION ALL
SELECT *, 2 sortby FROM TABLE_B
) dum
ORDER BY sortby
You don't really need to have parenthesis. You can sort directly:
SELECT *, 1 AS RN FROM TABLE_A
UNION ALL
SELECT *, 2 AS RN FROM TABLE_B
ORDER BY RN, COLUMN_1
Not an OP direct response, but I thought I would jimmy in here responding to the the OP's ERROR messsage, which may point you in another direction entirely!
All these answers are referring to an overall ORDER BY once the record set has been retrieved and you sort the lot.
What if you want to ORDER BY each portion of the UNION independantly, and still have them "joined" in the same SELECT?
SELECT pass1.* FROM
(SELECT TOP 1000 tblA.ID, tblA.CustomerName
FROM TABLE_A AS tblA ORDER BY 2) AS pass1
UNION ALL
SELECT pass2.* FROM
(SELECT TOP 1000 tblB.ID, tblB.CustomerName
FROM TABLE_B AS tblB ORDER BY 2) AS pass2
Note the TOP 1000 is an arbitary number. Use a big enough number to capture all of the data you require.
There will be times when you need to do something like this :
Pull top 5 from table 1 based on a sort
and bottom 5 from table 2 based on another sort
and union these together.
solution
select * from (
-- top 5 records
select top 5 col1, col2, col3
from table1
group by col1, col2
order by col3 desc ) z
union all
select * from (
-- bottom 5 records
select top 5 col1, col2, col3
from table2
group by col1, col2
order by col3 ) z
this was the only way i was able to get around the error and worked fine for me.
SELECT * FROM (SELECT *
FROM TABLE_A ORDER BY COLUMN_1)DUMMY_TABLE
UNION ALL
SELECT * FROM TABLE_B
ORDER BY 2;
2 is column number here .. In Oracle SQL you can use the column number by which you want to sort the data
This solved my SELECT statement:
SELECT * FROM
(SELECT id,name FROM TABLE_A
UNION ALL
SELECT id,name FROM TABLE_B ) dum
order by dum.id , dum.name
where id and name columns available in tables and you can use your columns .
Simply use that , no need parenthesis or anything else
SELECT *, id as TABLE_A_ID FROM TABLE_A
UNION ALL
SELECT *, id as TABLE_B_ID FROM TABLE_B
ORDER BY TABLE_A_ID, TABLE_B_ID
ORDER BY after the last UNION should apply to both datasets joined by union.
The solution shown below:
SELECT *,id AS sameColumn1 FROM Locations
UNION ALL
SELECT *,id AS sameColumn2 FROM Cities
ORDER BY sameColumn1,sameColumn2
select CONCAT(Name, '(',substr(occupation, 1, 1), ')') AS f1
from OCCUPATIONS
union
select temp.str AS f1 from
(select count(occupation) AS counts, occupation, concat('There are a total of ' ,count(occupation) ,' ', lower(occupation),'s.') As str from OCCUPATIONS group by occupation order by counts ASC, occupation ASC
) As temp
order by f1