I have these codes:
select case
when exists (select 1
from table1
where id=608071)
then column1
else 0
end as abc
from table1 where id=608071;
and
select decode(count(column1), 0, column1) abc
from (select column1
from table1
where id=608071) group by column1;
and none of them returns me no column1, no 0, no error. It gives me null, i.e. nothing. No rows return. I need to get 0 when particular id does not exist. What is wrong in here?
try this!!
select case when exists (select 1 from table1 where id= '608071') then (select column1 from table1) else '0' end as abc from dual
Assuming this is your requirement: "I need to get 0 when particular id does not exist"
select
nvl(T.COLUMN1, 0) COLUMN1_OR_ZERO
from
DUAL D left join(
select
*
from
TABLE1
where
id = '608071') T on (1=1)
With this query, you only scan the table once.
Related
Just wondering why the following select isn't working:
SELECT
A.FIELD1
, (SELECT PCN FROM (select B.PRIORITY, B.PCN
from
TABLE2 B
WHERE B.CUST= A.CUST
ORDER BY B.PRIORITY)
WHERE ROWNUM = 1) AS PCN
FROM TABLE1 A;
ERROR at line 2: ORA-00904: "A"."CUST": invalid identifier
Important to mention:
TABLE1 has as fields FIELD1, CUST.
TABLE2 has as fields PCN, PRIORITY, CUST.
Thanks in advance.
Your query shouldn't give you that error message, on when you remove the outer qiery this would happen
CREATE tABLE TABLE1 (FIELD1 int, CUST int)
INSERT INTO TABLE1 VALUES(1,1)
1 rows affected
CREATE TABLE TABLE2 (PCN int, PRIORITY int, CUST int)
INSERT INTO TABLE2 VALUES (1,1,1)
1 rows affected
SELECT
A.FIELD1
, (SELECT PCN FROM (select B.PRIORITY, B.PCN
from
TABLE2 B
WHERE B.CUST= A.CUST
ORDER BY B.PRIORITY)
WHERE ROWNUM = 1) AS PCN
FROM TABLE1 A;
FIELD1
PCN
1
1
fiddle
You can't nest inline selects (more than one level) without losing the ability of the inner nested selects being able to reference the parent block. So your query on TABLE2 cannot see the columns from TABLE1 because of this nesting.
Try this:
SELECT a.field1,
pcn.pcn
FROM table1 a,
(SELECT b.cust,
b.priority,
b.pcn,
ROW_NUMBER() OVER (PARTITION BY b.cust ORDER BY b.priority DESC) seq
FROM table2 b) pcn
WHERE a.cust = pcn.cust(+)
AND pcn.seq(+) = 1
That will work well for report queries. If you end up adding a filter on a specific customer, then you would be better off using OUTER APPLY if you have a recent-enough version of Oracle that supports that.
You could try this:
SELECT
A.FIELD1
, (SELECT B.PCN
from
TABLE2 B
WHERE B.CUST= A.CUST
ORDER BY B.PRIORITY
FETCH FIRST 1 ROWS ONLY) AS PCN
FROM TABLE1 A;
FETCH FIRST 1 ROWS ONLY gets you the first ordered record. Works on 12c and up and supports nesting, and no 2nd subquery needed.
Yet another option might be a CTE.
Sample data:
SQL> with
2 table1 (field1, cust) as
3 (select 1, 100 from dual union all
4 select 2, 200 from dual
5 ),
6 table2 (pcn, priority, cust) as
7 (select 10, 1, 100 from dual union all
8 select 20, 2, 100 from dual union all
9 select 30, 1, 200 from dual
10 ),
Query begins here. Rank rows by priority, and then fetch the ones that rank as the highest (line #20):
11 temp as
12 (select a.field1,
13 b.pcn,
14 rank() over (partition by a.field1 order by b.priority desc) rnk
15 from table1 a join table2 b on a.cust = b.cust
16 )
17 select field1,
18 pcn
19 from temp
20 where rnk = 1;
FIELD1 PCN
---------- ----------
1 20
2 30
SQL>
You may use first aggregate function to achieve the same (assuming that you have completely deterministic order by) functionality without nested subquery:
select
a.field1
, (
select max(b.pcn) keep(dense_rank first order by b.priority)
from table2 b
where b.cust = a.cust
) as pcn
from table1 a
which for this sample data
insert into table1 values(1,1);
insert into table1 values(2,2);
insert into table2 values(1,1,1);
insert into table2 values(2,2,1)
returns
FIELD1
PCN
1
1
2
(null)
SQL fiddle
I have table structure and data as below
https://ibb.co/mkGp67
I want a SQL Query to retrieve data only for those columns which have at least one not null value in it, in above case i want data comes out to be
https://ibb.co/mz9967
i.e. i don't need column Col2, Col5 and Col6, also which column having all null value is not fixed.
Please let me know the SQL query which retreive data that having only those column which having not null value with data as above.
As far, as I know, you will not be able to achieve this with an SQL query. One of the strong assumptions of SELECT statements is that the list of returned columns is static - defined in the query, not by the data. Even for PIVOT queries (available - as far, as I know - since Oracle 11), the list of columns is defined in the query, by providing a list of values to be converted to columns has to be explicitly given.
What you are looking for is some kind of code, dynamically generating the query. This can be PL/SQL, returning cursor references or any application code.
Edit:
What you could do with a query, is to have a clear information on which columns do contain nulls, which do not, etc. It could look something like this:
SELECT CASE
WHEN COUNT(*) = 0 THEN 'no rows'
WHEN COUNT(Col1) = 0 THEN 'all NULLs'
WHEN COUNT(Col1) = COUNT(*) THEN 'no NULLs'
ELSE 'some NULLs'
END Col1NullStatus,
CASE
WHEN COUNT(*) = 0 THEN 'no rows'
WHEN COUNT(Col2) = 0 THEN 'all NULLs'
WHEN COUNT(Col2) = COUNT(*) THEN 'no NULLs'
ELSE 'some NULLs'
END Col2NullStatus,
CASE
WHEN COUNT(*) = 0 THEN 'no rows'
WHEN COUNT(Col3) = 0 THEN 'all NULLs'
WHEN COUNT(Col3) = COUNT(*) THEN 'no NULLs'
ELSE 'some NULLs'
END Col3NullStatus,
CASE
WHEN COUNT(*) = 0 THEN 'no rows'
WHEN COUNT(Col4) = 0 THEN 'all NULLs'
WHEN COUNT(Col4) = COUNT(*) THEN 'no NULLs'
ELSE 'some NULLs'
END Col4NullStatus,
CASE
WHEN COUNT(*) = 0 THEN 'no rows'
WHEN COUNT(Col5) = 0 THEN 'all NULLs'
WHEN COUNT(Col5) = COUNT(*) THEN 'no NULLs'
ELSE 'some NULLs'
END Col5NullStatus,
CASE
WHEN COUNT(*) = 0 THEN 'no rows'
WHEN COUNT(Col6) = 0 THEN 'all NULLs'
WHEN COUNT(Col6) = COUNT(*) THEN 'no NULLs'
ELSE 'some NULLs'
END Col6NullStatus
FROM myTable
See SQL Fiddle for the above.
Edit 2:
And the output of this query would look something like this:
Col1NullStatus | Col2NullStatus | Col3NullStatus | Col4NullStatus | Col5NullStatus | Col6NullStatus
---------------+----------------+----------------+----------------+----------------+----------------
no NULLs | all NULLs | some NULLs | no NULLs | all NULLs | all NULLs
This is the format, you could be using, to post your input data and expected results.
So, since you give no no formal table structure, and you seem to be confusing numbers and chars(s), I will do my best to try and make a query that will at least produce the results you want.
create table foo as (
col1 varchar(10),
col2 varchar(10),
col3 varchar(10),
col4 varchar(10),
col5 varchar(10),
col6 varchar(10)
);
select *
CASE cust1 WHEN null then 'null' else cust1 as cust1 end,
CASE cust2 WHEN null then 'null' else cust1 as cust1 end,
CASE cust3 WHEN null then 'null' else cust1 as cust1 end,
CASE cust4 WHEN null then 'null' else cust1 as cust1 end,
CASE cust5 WHEN null then 'null' else cust1 as cust1 end,
CASE cust6 WHEN null then 'null' else cust1 as cust1 end
from foo ;
As per below query , I able to get not null columns at row-level col1,col3 and col4.
Query :
select 'col1' as "Name",col1 from temp
where exists (select 1
from temp
group by to_char(col1)
having (count(to_char(col1)))> 0)
union all
select 'col2' as "Name",to_char(col2) from temp
where exists (select 1
from temp
group by to_char(col2)
having (count(to_char(col2)))> 0)
union all
select 'col3' as "Name" , to_char(col3) from temp
where exists (select 1
from temp
group by to_char(col3)
having (count(to_char(col3)))> 0)
union all
select 'col4'as "Name" , to_char(col4) from temp
where exists (select 1
from temp
group by to_char(col4)
having (count(to_char(col4)))> 0)
union all
select 'col5' as "Name" , to_char(col5) from temp
where exists (select 1
from temp
group by to_char(col5)
having (count(to_char(col5)))> 0)
union all
select 'col6' as "Name" , to_char(col6) from temp
where exists (select 1
from temp
group by to_char(col6)
having (count(to_char(col6)))> 0)
output:
col1 A
col1 B
col1 C
col1 D
col3 10
col3 20
col3 -
col3 10
col4 12
col4 23
col4 34
col4 43
I tried to make this output of rows to columns but I couldn't make it in single query ... Hope this will be helpful ...
I would do this usually in three steps.
Firstly, make sure that the table statistics are up to date. Check if last_analyzed is later than the last change to the table.
SELECT last_analyzed FROM user_tables WHERE table_name = 'MYTABLE';
If in doubt, update the statistics with
BEGIN dbms_stats.gather_table_stats('MYSCHEMA','MYTABLE'); END;
/
Now, the view user_tab_columns has a column num_nulls. This is the number of rows where this column is NULL. If the value is the same than the number of rows in the table, all rows are NULL. This can be used to let Oracle generate the required SQL:
WITH
qtab AS (SELECT owner, table_name, num_rows
FROM all_tables
WHERE owner='SCOTT' -- change to your schema
AND table_name='EMPLOYEES' -- change to your table name
),
qcol AS (SELECT owner, table_name, column_name, column_id
FROM qtab t
JOIN all_tab_columns c USING (owner, table_name)
WHERE c.nullable = 'N' -- protected by NOT NULL constraint
OR c.num_nulls = 0 -- never NULL
OR c.num_nulls < t.num_rows -- at least 1 row is NOT NULL
)
)
SELECT 'SELECT '||LISTAGG(column_name,',') WITHIN GROUP (ORDER BY column_id)||
' FROM '||owner||'.'||table_name||';' AS my_query
FROM qcol
GROUP BY owner, table_name;
This will output a query like
SELECT col1, col3, col4, col5 FROM myschema.mytable;
This query can now be executed to show the column values.
It seems that I haven't been clear enough.
The query that seems to work is:
Select ((Select count (table1.id) from table1 where table1.code=2 and table1.name=5) as ‘name5’,
(Select count (table1.id) from table1 where table1.code=2 and table1.name=7) as ‘name7’)
From table.1;
union
Select ((Select count (table1.id) from table1 where table1.code=5 and table1.name=5) as ‘name5’,
(Select count (table1.id) from table1 where table1.code=5 and table1.name=7) as ‘name7’)
From table.1;
union
Select ((Select count (table1.id) from table1 where table1.code=15 and table1.name=5) as ‘name5’,
(Select count (table1.id) from table1 where table1.code=15 and table1.name=7) as ‘name7’)
From table.1;
….
Which gets an outcome like this:
name5 name7
52 47
42 84
61 11
My problem is that the table1.code has a thousand and more values other than 2,5 and 15 and I can not repeat a union statement for so many times.
Well it seems like you actually just want to group by the values in the code column, and you can use IN or EXISTS
select count(table1.id) as theCount, table1.code as theCode
from table1 where table1.code in ('code a','code b', 'etc...')
group by table1.code;
the output would be
theCount||theCode
code a || 8074
code b || 34
etc... || 9575
or something like that but with non notional numbers for counts
HTH
You could try to list all values in a nested select listing integers from a to your value, e.g. 100, like that:
select count table1.id from table1 one where table1.code in (
select rownum from all_objects where rownum < 100
);
or if you don't want to start at "1":
select count table1.id from table1 one where table1.code in (
select rownum n from dual connect by level 10 where n>3
);
I have a table table1 below is how the data looks like.
Column1 is my foreign key of another table.
Column1 Column2 Column3
1 A 06/MAY/14
1 A 05/MAY/14
1 B 06/MAY/14
1 B 01/JAN/00
1 A 01/JAN/00
Now i want to find distinct column1 values where it meets the following condition.
1.atleast one record where column2 should be A and column3 should be (sysdate - 1)
AND
2.atleast one record where column2 should be B and column3 should be (sysdate - 1)
Meaning alteast one A and B should have their column 3 populated with (sysdate - 1)
I have written the below query, please tell if i'm doing anything wrong.
I also want to know if i'm doing the right way of joining. The table contains around 50K records and performance should be fine i guess.
SELECT DISTINCT COLUMN1 FROM
TABLE1 A
JOIN
TABLE1 B ON (A.COLUMN1 = B.COLUMN1)
WHERE
((TRUNC(A.COLUMN3) - TRUNC(A.COLUMN3) = 0)
AND TRUNC(A.COLUMN3) = TRUNC(SYSDATE - 1)
AND TRUNC(B.COLUMN3) = TRUNC(SYSDATE - 1)
AND A.COLUMN2 = 'A'
AND B.COLUMN2 = 'B'
AND TO_CHAR(A.COLUMN3, 'DD-MON-YY') != '01-JAN-00'
AND TO_CHAR(B.COLUMN3, 'DD-MON-YY') != '01-JAN-00'
);
For performance-comparison one with subselects and group:
SELECT COLUMN1 FROM (
SELECT
COLUMN1,
COUNT(COLUMN2) CNT
FROM (
SELECT DISTINCT
COLUMN1,
COLUMN2
FROM TABLE1
WHERE TRUNCATE(COLUMN3) = SYSDATE - 1 AND
(COLUMN2 = 'A' OR COLUMN2 = 'B'))
GOUP BY COLUMN1)
WHERE CNT = 2
This should work
SELECT DISTINCT A.column1 -- Obtain distinct from A
FROM table1 A -- TableA
join table1 B -- TableB
ON A.column1 = B.column1 -- Joining them on Column1
WHERE A.column3 = SYSDATE - 1 -- Yesterdays data on Table A
AND A.column2 = 'A' -- A values
AND B.column2 = 'B'; -- B Values
Note: No distinctness in your test case. So try with a unique key.
I'm new to Oracle and having knowledge of MS SQL. I'm trying to get a phone number depending upon the user_id from Table2 and here is the business logic:
Case1: if a single match is found in Table1 then get it's respective toll free number from Table2
Case2: if no match is found in Table1 then get the default toll free number from Table2
Case3: if an multiple match is found in Table1 then for all those assigned_care_levels get the Care value from Table2 ordered by asc or desc and select the top row phone number.
I wrote the following query which works fine when I run it individually. However, when I cobine it using the if else statements I'm getting the following error ERROR: ORA-00907: missing right parenthesis. Here is my code:
if ((select count(distinct care_level) from Table1 where user_id = '100') > 0)
select phone from Table2 where care_level in (select distinct care_level from Table1 where user_id = '100')
and rownum = 1
order by care_level asc
else if((select count(distinct care_level) from Table1 where user_id = '100') = 0)
select phone from Table2 where care_level = 'default'
SET SERVEROUTPUT ON;
DECLARE
v_CARE_COUNT NUMBER := 0;
v_PHONE VARCHAr2(40) := NULL;
BEGIN
select count(distinct care_level)
into v_CARE_COUNT
from Table1
where user_id = '100';
IF(v_CARE_COUNT > 0) THEN
select phone into v_PHONE
from Table2
where care_level in
(select distinct care_level from Table1 where user_id = '100')
and rownum = 1;
ELSE
select phone into v_PHONE
from Table2
where care_level = 'default';
END IF;
DBMS_OUTPUT.PUT_LINE('PHONE is <'||v_PHONE||'>');
EXCEPTION
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('Exception : '||SQLERRM);
END;
/
EDIT: ( AS SIngle SQL)
SELECT PHONE
FROM TABLE2
WHERE CARE_LEVEL in
(
SELECT CARE_LEVEL FROM TABLE1 WHERE USER_ID='100'
UNION
SELECT CARE_LEVEL FROM TABLE1 WHERE CARE_LEVEL='default'
AND NOT EXISTS
(SELECT 'X' FROM TABLE1 WHERE USER_ID='100')
)
AND ROWNUM = 1;
The 'else if' syntax is wrong. In Oracle you need to use 'ELSIF' and complete the whole conditional statement with an 'END IF'. The SQL statements within should also be followed with a ;
Try:
IF ((select count(distinct care_level) from Table1 where user_id = '100') > 0) THEN
select phone from Table2 where care_level in (select distinct care_level from Table1 where user_id = '100')
and rownum = 1
order by care_level asc;
ELSIF ((select count(distinct care_level) from Table1 where user_id = '100') = 0) THEN
select phone from Table2 where care_level = 'default'; END IF