SELECT *
FROM REVIEW
WHERE REVIEWERID =5 AND APPRAISEECONFIRMYN='Y' AND HRCONFIRMYN = NULL
Are 2 'AND' conditions allowed like this? I'm not getting the correct output. There are 2 records in the database that fulfil the above conditions. When I remove the last condition 'HRCONFIRMYN = NULL' and execute, I get the correct output.
How can this be solved? I need to check all 3 conditions whilst searchng the records.
To compare the NULL values, you have to use the IS NULL predicate instead of = NULL like so:
SELECT *
FROM REVIEW
WHERE REVIEWERID = 5
AND APPRAISEECONFIRMYN = 'Y'
AND HRCONFIRMYN IS NULL
use OR instead
group your condition
use IS NULL when comparing with NULLs
query,
SELECT *
FROM REVIEW
WHERE (REVIEWERID =5 AND APPRAISEECONFIRMYN='Y') OR
HRCONFIRMYN IS NULL
Related
I have below query which i am trying to run but not returning the expected result. The ISIN field value which is Null in EXPORT_BB is also getting ignore and not showing the result with the condition given in NOT IN clause. The export_blacklist has only one row value and which is not Null but still i dont for what reason the null value is getting ignored.
Select * from EXPORT_BB where ISIN NOT IN
(
SELECT
ISIN
FROM
export_blacklist);
If i run only select query without the NOT IN clause then i can see values which is NULL for ISIN field.
JUst for test i tried below query and its also resulting nothing. Is it bug in Oracle 18c or something is missing?
select 'null is not in set' from dual where null not in (select 1 from dual);
Any comparison of NULL with =, <>, <, > or in a IN or NOT IN clause will return NULL, so that row is not included in the results (because only rows for which the returned value is TRUE will be included in the results).
Change your code with a condition for the case that ISIN is NULL:
SELECT * FROM EXPORT_BB
WHERE ISIN NOT IN (SELECT ISIN FROM export_blacklist)
OR ISIN IS NULL
NULL values doesn't work with NOT IN it's the normal behaviour.
You have to convert the NULL to another value to be able to operate with it or use IS NULL/IS NOT NULL
Select * from EXPORT_BB where NVL(ISIN, 999999) NOT IN
(
SELECT
NVL(ISIN, 999999)
FROM
export_blacklist);
Comparing to a null value in Oracle always returns false.
Is NULL >= 1? No.
Is NULL < 1? No.
Is NULL in your set? Regardless of what your set is, the answer is no.
Is NULL not in your set? Again, no.
It is the expected behaviour. NOt related to 18c it is the same way from Oracle 7 onwards
NOT IN doesnt consider nulls.
NOT EXISTS does consider nulls.
Consider the following example in db fiddle
https://dbfiddle.uk/?rdbms=oracle_18&fiddle=8be0a790d8172093a032602345038e8e
See a discussion on this
https://asktom.oracle.com/pls/apex/asktom.search?tag=in-vs-exists-and-not-in-vs-not-exists
As you have been answered by collegues you have to specify that you wanna return null values too.
Namely
SELECT *
FROM EXPORT_BB
WHERE ISIN NOT IN (SELECT ISIN FROM EXPORT_BLACKLIST)
OR ISIN IS NULL;
I have a table PATIENT with Column STATUS. When I queried to get STATUS not equal to 1, I was expecting the result as NULL and 2.
But I am only getting 2 as the result. Can someone help me with this?
CREATE TABLE #PATIENT
(STATUS INT)
INSERT INTO #PATIENT (STATUS)
SELECT 1
UNION
SELECT 2
UNION
SELECT NULL
SELECT * FROM #PATIENT WHERE STATUS <> 1
When I queried with
SELECT * FROM #PATIENT WHERE ISNULL(STATUS, 0) != 1
I am able to get NULL and 2 as the result.
This is SQL SERVER 2012.
You can use OR in WHERE with Condition STATUS IS NULL .
SELECT * FROM #PATIENT WHERE STATUS <> 1 OR STATUS IS NULL
This will do it.
EDIT:
Conceptually, NULL means “a missing unknown value” and it is
treated somewhat differently from other values.
You cannot use arithmetic comparison operators such as =, <, or <>
to test for NULL
Because the result of any arithmetic comparison with NULL is also
NULL, you cannot obtain any meaningful results from such comparisons
we can not equate or not equate anything with null, thats why IS NULL
SELECT NULL <> 1 ===> NULL
Even though it is supposed to be true, it will return `NULL`
Hope this helps.
When you compare NULL value to any value then the result is always NULL.
So if you wan to select the NULL value as well then try this:
SELECT * FROM #PATIENT WHERE STATUS <> 1 OR STATUS IS NULL
DEMO
Conceptually "NULL" means a missing value. To test for NULL IS NULL or IS NOT NULL condition is used. Arithmetic operators cannot be used for comparing NULL values.
NULL<>1 :: returns false because NULL can be 1 or any other value (an unknown value).
Null is a special marker used in Structured Query Language (SQL) to indicate that a data value does not exist in the database.
And reason because you got only 2 and NOT NULL is because in SQL nothing is equal to NULL but also nothing is NOT equal to NULL.
In Simple words you cannot equate and not equate any value with NULL.
I want to generate a SQL query to get null count in a particular column like
SELECT COUNT (column) AS count
FROM table
WHERE column = null ;
This is returning 0, but I want how many null values are present in that column like
SELECT COUNT (column) AS count
FROM table
WHERE column = 'some value';
which returns the count of the matched records
NULL value is special in that you cannot use = with it; you must use IS NULL instead:
SELECT COUNT (*) AS count FROM table where column IS null ;
This is because NULL in SQL does not evaluate as equal to anything, including other NULL values. Also note the use of * as the argument of COUNT.
You can use a conditional sum()
SELECT sum(case when column is null
then 1
else 0
end) AS count
FROM table
A different query but exact answer check it out
select count(*)-count(column) from table
please vote check this as answer if it helps you
To get exact output you can use below command as well -
SELECT COUNT (*) AS count FROM table where column IS null OR column='';
because some times only '' doesn't counted as NULL.
I have 2 tables (stud and stud1). Both having 2 columns but stud1 contains 1 record which is null.
I have created following 2 queries.First one is returning the accurate result but other one which is using not in returning nothing. I guess that is because of the null value. But I don't understand the reason for it. Can someone help me with this?
See NOT IN clause and NULL values.
That's because your 2nd query equals:
SELECT * FROM #stud
WHERE ID <> NULL
When ansi_nulls is on, ID <> NULL is unknown, so you won't get any rows.
How do I write a query that if one column value is not null then compare the value with the querystring, else do not compare the column value.
for example, I have a tbl1 with programs1 and programs2 two columns, the value in these two columns can be null or with value. I want to have the if statement that say
if programs1 is not null, programs1=#programs and
if programs2 is not null, programs2=#programs
my query is like this:
select * from tbl1 where
(programs1 is not null and programs1=#programs)
and
(program2 is not null and programs2=#programs)
but it didn't work the way I want. How do I write a correct query for this case? TIA.
I believe you're looking for COALESCE.
WHERE COALESCE(programs1, programs2) = #Programs
However, if you'd like to compare only if it has a value:
-- If the column is null, ignore it. If it has a value, then
-- check that value.
WHERE (programs1 IS NULL OR programs1 = #Programs)
AND (programs2 IS NULL OR programs2 = #Programs)
Also, I assume you mean sql-server since you reference asp.net
ISNULL(programs1,programs2) = #Programs
or
(programs1 is not null and #Programs = programs1) or (programs2 is not null and #Programs = programs2)
select *
from tbl1
where (programs1=#programs or programs1 is null)
and (programs2=#programs or programs2 is null)