Where doesn't affect. Why? - sql

I have an MySQL Query looks like that:
SELECT
client.id, client.vorname, client.nachname, DATE_FORMAT(geburtsDatum, '%d.%m.%Y'), zahlung.zuUebBet, zahlung.betrag
FROM
zahlung JOIN client ON ( zahlung.mitgliedsNr = client.id )
WHERE
client.typ = 'U'
OR
client.typ is null
AND
zahlung.typ = 'Beitrag'
AND
anBGueberwiesen = '0000-00-00'
AND
zahlung.zuUebBet IS NOT NULL
AND
(
zahlung.vomBGeinheb = 0
OR
zahlung.vomBGeinheb is null
)
All work fine but the case:
zahlung.zuUebBet IS NOT NULL
looks like beeing ignored. (I get rows with lots of NULL in it)
Anyone know whats going on?

please take a look at the operator precedence of mysql. OR has a lower precedence than AND, so you'll have to put this into braces to get the desired result:
client.typ = 'U'
OR
client.typ is null
the complete WHERE-block should look like this:
(
client.typ = 'U'
OR
client.typ is null
)
AND
zahlung.typ = 'Beitrag'
AND
anBGueberwiesen = '0000-00-00'
AND
zahlung.zuUebBet IS NOT NULL
AND
(
zahlung.vomBGeinheb = 0
OR
zahlung.vomBGeinheb is null
)
otherwise, the sql-statement would be treated like the following (wich isn't what you wanted, i think) (i've added braces to make things clear):
client.typ = 'U'
OR
(
client.typ is null
AND
zahlung.typ = 'Beitrag'
AND
anBGueberwiesen = '0000-00-00'
AND
zahlung.zuUebBet IS NOT NULL
AND
(
zahlung.vomBGeinheb = 0
OR
zahlung.vomBGeinheb is null
)
)

use proper multi level parentheses in between your where conditions.
You have used parentheses in last part, but the AND, OR's for the first few conditions are also required to be parenthesized.

!ISNULL('zahlung.zuUebBet') try this one instead of zahlung.zuUebBet IS NOT NULL. I still have no explanation why this works, but it did change results for me more than once.
For anyone more knowledgable on MySQL, please explain why !ISNULL(<row>); != <row> IS NOT NULL.

Related

isnull with AND : -An expression of non-boolean type specified in a context where a condition is expected, near 'and'

I am tryng to use isnull with AND operator
SELECT *
FROM contacts AS cont
LEFT JOIN contactphones AS contPhone
ON cont.contactid = contPhone.contactid
LEFT JOIN sys_phonetypedesc AS phont
ON phont.typeid = contPhone.phonetype
LEFT JOIN salutations AS tsal
ON tsal.salutid = cont.salutation
WHERE cont.contactid = '29'
AND ( Isnull(phont.typedesc, 1) )
AND ( Isnull(contPhone.phonenum, 1) )
ORDER BY phont.typedesc
but got following error
An expression of non-boolean type specified in a context where a
condition is expected, near 'and'.
I also tried using the case statement
SELECT *
FROM contacts AS cont
LEFT JOIN contactphones AS contphone
ON cont.contactid = contphone.contactid
LEFT JOIN sys_phonetypedesc AS phont
ON phont.typeid = contphone.phonetype
LEFT JOIN salutations AS tsal
ON tsal.salutid = cont.salutation
WHERE cont.contactid = '29'
AND (
CASE
WHEN phont.typedesc = NULL THEN 1
ELSE phont.typedesc
END as a)
but it is not working. I am looking for ifnull logic in MSSQL but case and if else not working correctly
please suggest
I don't think you need to use ISNULL() here, instead you are looking for IS NULL/IS NOT NULL. First let's see why you get this error message
An expression of non-boolean type specified in a context where a condition is expected, near 'and'.
You get this error because ( Isnull(phont.typedesc, 1) ) is not a boolean expression and that what the WHERE clause needs (True or False).
eg: Let's assume phont IS NULL, then ISNULL() will return 1, so you are writing cont.contactid = '29' AND 1 AND ....
What should I do then to get ride of this error?
Just make it a boolean expression as Isnull(phont.typedesc, 1) = 1 or what ever you want instead of =1, it maybe other too because it's not clear what you need to check.
Now, the use of ISNULL() as I seeis point less, cause the possible cases I can see is like the follow:
Isnull(phont.typedesc, 1) = 1 then directly phont IS NULL.
Isnull(phont.typedesc, 1) <> 1 then directly phont IS NOT NULL.
Isnull(phont.typedesc, 1) = AnyValue then why not directly phont = value or phont IN(<Values>) if you are looking for more than 1 value.
You're not comparing the result of isnull to anything in your where clause.
(isnull(phont.TypeDesc,1))
gives you either the TypeDesc, or if it's null gives you 1, but then you move directly onto an AND statement. In other words, if all relevant fields are null, what you'd be trying to do is:
where cont.ContactID = '29' and 1 and 1
You either have the isnull in the wrong place (if you want see it in your selected fields), or you forgot to compare it to something.
If you want to select rows where those fields are actually null then what you want is:
where cont.ContactID = '29'
and phont.TypeDesc is null
and contPhone.PhoneNum is null
select * from contacts as cont left join ContactPhones as contPhone on cont.ContactID=contPhone.ContactID
left join SYS_PhoneTypeDesc as phont on
phont.TypeID = contPhone.PhoneType
left join SALUTATIONS as tsal on tsal.salutid = cont.Salutation where cont.ContactID = '29' and (isnull(phont.TypeDesc,1))=check what u want here
and (isnull(contPhone.PhoneNum,1))=check what u want here enter code here
order by
phont.TypeDesc
Isnull(contPhone.phonenum,1) return 1 when your contPhone.phonenum value will be null else it will return that column value but the point is you got error because you have not used any comparison value as a result it thrown error
Your condition will be like below
Where contactId=29 and isnull(phonenum,1)= // any value

change where condition based on column value

I faced the following requirement. The following query is called by a procedure. The value p_pac_code is the input parameter of the procedure.
The requirement is the query should have an additional condition sp_sbsp.SUBSPCLTY_CODE!='C430 if the p_pac_code value is '008'.
For any other p_pac_code value, it should run as it is below. Is there way to do this by adding an additional condition in the WHERE clause?
As for now, I have done this using IF.....ELSE using the query two times separately depending on p_pac_code value. But I am required to find a way to do with just adding a condition to this single query.
SELECT ptg.group_cid
FROM PRVDR_TYPE_X_SPCLTY_SUBSPCLTY ptxss,
PT_X_SP_SSP_STATUS pxsst ,
pt_sp_ssp_x_group ptg,
group_x_group_store gg,
specialty_subspecialty sp_sbsp,
treatment_type tt,
provider_type pt
WHERE
pt.PRVDR_TYPE_CODE = ptxss.PRVDR_TYPE_CODE
AND tt.TRTMNT_TYPE_CODE = pxsst.TRTMNT_TYPE_CODE
AND ptxss.PRVDR_TYPE_X_SPCLTY_SID = pxsst.PRVDR_TYPE_X_SPCLTY_SID
AND tt.TRTMNT_TYPE_CODE = p_pac_code
AND TRUNC(SYSDATE) BETWEEN TRUNC(PXSST.FROM_DATE) AND TRUNC(PXSST.TO_DATE)
AND ptg.prvdr_type_code =ptxss.prvdr_type_code
AND ptg.spclty_subspclty_sid = ptxss.spclty_subspclty_sid
AND ptxss.spclty_subspclty_sid = sp_sbsp.spclty_subspclty_sid
AND ptg.spclty_subspclty_sid = sp_sbsp.spclty_subspclty_sid
AND ptg.status_cid = 2
AND ptg.group_cid = gg.group_cid
AND gg.group_store_cid = 16
AND gg.status_cid = 2;
Thanks in advance.
You can simply add a condition like this:
... and (
( sp_sbsp.SUBSPCLTY_CODE!='C430' and p_pac_code = '008')
OR
NVL(p_pac_code, '-') != '008'
)
This can be re-written in different ways, this one is quite self-explanatory
Just add:
AND NOT ( NVL( sp_sbsp.SUBSPCLTY_CODE, 'x' ) = 'C430'
AND NVL( p_pac_code value, 'x' ) = '008' )
to the where clause.
The NVL function is used so that it will match NULL values (if they exist in your data); otherwise, even though NULL does not match C430 you will still find that NULL = 'C430' and NULL <> 'C430' and NOT( NULL = 'C430' ) will all return false.
Quite easy. Add the following condition:
AND (sp_sbsp.SUBSPCLTY_CODE != 'C430' OR p_pac_code value != '008')
(don't forget the parenthesis)
Just sharing
SELECT ptg.group_cid
FROM PRVDR_TYPE_X_SPCLTY_SUBSPCLTY ptxss
WHERE
pt.PRVDR_TYPE_CODE = ptxss.PRVDR_TYPE_CODE
&&((tt.TRTMNT_TYPE_CODE = pxsst.TRTMNT_TYPE_CODE)
or (tt.TRTMNT_TYPE_CODE = pxsst.TRTMNT_TYPE_CODE))
just use the parenthesis to specify where the conditionmust implement.

SQL: field = other_field returns false even if they are identical (NULL values)

I have a difficulty because when comparing two fields in a subquery, although the fields are identical i.e. they both have NULL values, the comparison returns a FALSE result
Therfore NULL = NULL is returning FALSE
Now I know that NULLs are supposed to be compared with the IS operator, however when I compare two fields how am I supposed to know they contain a null? I need to compare two fields for identical data both if the values are NULL or not.
Consider this SQL:
SELECT
*
FROM
fts.fts_customers_data_50360001
WHERE
fts.fts_customers_data_50360001.record_type = 15
AND
fts.fts_customers_data_50360001.mid = 103650360001
AND NOT EXISTS
(
SELECT
fts.temp_fees_50360001.record_type
FROM
fts.temp_fees_50360001
WHERE
fts.temp_fees_50360001.record_type = fts.fts_customers_data_50360001.record_type
AND
fts.temp_fees_50360001.merch_id = fts.fts_customers_data_50360001.mid
AND
fts.temp_fees_50360001.fee_curr = fts.fts_customers_data_50360001.currency
AND
fts.temp_fees_50360001.card_scheme = fts.fts_customers_data_50360001.card_scheme
AND
fts.temp_fees_50360001.tran_type = fts.fts_customers_data_50360001.fee_type
AND
fts.temp_fees_50360001.area = fts.fts_customers_data_50360001.region
AND
fts.temp_fees_50360001.srvc_type = fts.fts_customers_data_50360001.card_type
);
In the query above,
fts.temp_fees_50360001.card_scheme = fts.fts_customers_data_50360001.card_scheme
both have NULL values inside but the comparison returns false .. too bad
ANY IDEAS WOULD BE MUCH APPRECIATED
As the others have pointed out, NULL cannot be compared with NULL.
In Postgres you can shorten your expressions by using the operator IS DISTINCT FROM which is a null-safe replacement for <>. In your case you'd need to use IS NOT DISTINCT FROM to compare for equality (looks a bit the wrong way round but unfortunately there is no corresponding IS EQUAL TO defined in the SQL standard).
From the manual:
Ordinary comparison operators yield null (signifying "unknown"), not true or false, when either input is null. For example, 7 = NULL yields null, as does 7 <> NULL. When this behavior is not suitable, use the IS [ NOT ] DISTINCT FROM constructs:
So, instead of
(fts.temp_fees_50360001.record_type = fts.fts_customers_data_50360001.record_type
OR (fts.temp_fees_50360001.record_type IS NULL
AND fts.fts_customers_data_50360001.record_type IS NULL)
)
you can use:
(fts.temp_fees_50360001.record_type IS NOT DISTINCT FROM fts.fts_customers_data_50360001.record_type)
to handle NULL values automatically. The condition looks a bit strange if you want to compare for equality but it still is quite short.
First of all, use aliases for your tables, your query will be MUCH more readable:
select *
from fts.fts_customers_data_50360001 as d
where
d.record_type = 15 and
d.mid = 103650360001 and
not exists
(
select *
from fts.temp_fees_50360001 as f
where
f.record_type = d.record_type and
f.merch_id = d.mid and
f.fee_curr = d.currency and
f.card_scheme = d.card_scheme and
f.tran_type = d.fee_type and
f.area = d.region and
f.srvc_type = d.card_type
)
As for your question, there's several ways to do this, for example, you can use syntax like this:
...
(
f.card_scheme is null and d.card_scheme is null or
f.card_scheme = d.card_scheme
)
...
Or use coalesce with some value that couldn't be stored in your column:
...
coalesce(f.card_scheme, -1) = coalesce(d.card_scheme, -1)
...
Recently I also like using exists with intersect for this type of comparisons:
...
exists (select f.card_scheme, f.tran_type intersect select d.card_scheme, d.tran_type)
...
Just a side note - you have to be careful when writing queries like this and check query plans to be sure your indexes are used.
In SQL, null is never equal to null. The only way to get a true result for a comparison with null is via the special tests:
IS NULL
IS NOT NULL
In your case, you must cater specifically for the "two nulls" case being considered equal:
AND (fts.temp_fees_50360001.card_scheme = fts.fts_customers_data_50360001.card_scheme
OR (fts.temp_fees_50360001.card_scheme IS NULL
AND fts.fts_customers_data_50360001.card_scheme IS NULL)
)
There's no getting around dealing with it (although there are a few variations).
The following inner SELECT works (but I give no guarantee regarding performance):
SELECT
fts.temp_fees_50360001.record_type
FROM
fts.temp_fees_50360001
WHERE
(fts.temp_fees_50360001.record_type = fts.fts_customers_data_50360001.record_type
OR (fts.temp_fees_50360001.record_type IS NULL AND fts.fts_customers_data_50360001.record_type IS NULL))
AND
(fts.temp_fees_50360001.merch_id = fts.fts_customers_data_50360001.mid
OR (fts.temp_fees_50360001.merch_id IS NULL AND fts.fts_customers_data_50360001.mid IS NULL))
AND
(fts.temp_fees_50360001.fee_curr = fts.fts_customers_data_50360001.currency
OR (fts.temp_fees_50360001.fee_curr IS NULL AND fts.fts_customers_data_50360001.currency IS NULL))
AND
(fts.temp_fees_50360001.card_scheme = fts.fts_customers_data_50360001.card_scheme
OR (fts.temp_fees_50360001.card_scheme IS NULL AND fts.fts_customers_data_50360001.card_scheme IS NULL))
AND
(fts.temp_fees_50360001.tran_type = fts.fts_customers_data_50360001.fee_type
OR (fts.temp_fees_50360001.tran_type IS NULL AND fts.fts_customers_data_50360001.fee_type IS NULL))
AND
(fts.temp_fees_50360001.area = fts.fts_customers_data_50360001.region
OR (fts.temp_fees_50360001.area IS NULL AND fts.fts_customers_data_50360001.region IS NULL))
AND
(fts.temp_fees_50360001.srvc_type = fts.fts_customers_data_50360001.card_type
OR (fts.temp_fees_50360001.srvc_type IS NULL AND fts.fts_customers_data_50360001.card_type))

Where clause in sql

My sql query is as follows
IF #StatusId = 10
BEGIN
SELECT
*
FROM
Risk AS R
INNER JOIN Statuses AS St ON R.Status_Id=St.Status_Id
WHERE
R.MitigationOwner = COALESCE(#MitigationOwner,R.MitigationOwner)
AND R.RiskFactor = COALESCE(#RiskFactor,R.RiskFactor)
AND R.RiskArea = COALESCE(#RiskArea,R.RiskArea)
AND R.AddedWhen BETWEEN
COALESCE(CONVERT(DATETIME, #StartDate+'00:00:00',120),R.AddedWhen) AND
COALESCE(CONVERT(DATETIME,#EndDate+'23:59:59',120),R.AddedWhen)
END
When I pass only status Id and all other variables are null, then records with NULL MitigationOwner or ModifiedDate are not displayed..
What is wrong in this query?
Use the form:
...
(R.MitigationOwner = #MitigationOwner OR #MitigationOwner IS NULL)
...
This is optimised in SQL Server. COALESCE isn't.
Edit: This does the same as Paul Williams' answer but his answer allows explicit "NULL = NULL" matches. m ylogic is simpler because NULL never equals NULL.
I believe that by ModifiedDate you meant R.AddedWhen
try this:
SELECT
*
FROM
Risk AS R
INNER JOIN Statuses AS St ON R.Status_Id=St.Status_Id
WHERE
(R.MitigationOwner = COALESCE(#MitigationOwner,R.MitigationOwner) OR R.MitigationOwner IS NULL)
AND R.RiskFactor = COALESCE(#RiskFactor,R.RiskFactor)
AND R.RiskArea = COALESCE(#RiskArea,R.RiskArea)
AND (R.AddedWhen BETWEEN
COALESCE(CONVERT(DATETIME, #StartDate+'00:00:00',120),R.AddedWhen) AND
COALESCE(CONVERT(DATETIME,#EndDate+'23:59:59',120),R.AddedWhen) OR R.AddedWhen IS NULL)
If R.MitigationOwner can be null, then your comparison clause:
WHERE
R.MitigationOwner = COALESCE(#MitigationOwner,R.MitigationOwner)
Must be rewritten to handle NULL values:
WHERE
((R.MitigationOwner IS NULL AND #MitigationOwner IS NULL)
OR (R.MitigationOwner = #MitigationOwner))
See this article on Wikipedia about NULL.

SQL Server: WHERE clause to ignore blank GUID

SELECT ...
FROM ...
WHERE CASE WHEN #ActivityUID = '00000000-0000-0000-0000-000000000000'
THEN
-- do nothing
ELSE
(Activity.ActivityUID = #ActivityUID)
END
When a blank Guid is passed in via ActivityUID then I want the WHERE statement to ignore Activity.ActivityUID = #ActivityUID
WHERE (
Activity.ActivityUID = #ActivityUID OR
#ActivityUID = '00000000-0000-0000-0000-000000000000'
)
This removes the need for an OR clause because NULL comparisons fail.
WHERE
Activity.ActivityUID = NULLIF(#ActivityUID, '00000000-0000-0000-0000-000000000000')
See if there is a performance difference...