I have a contact table I wish to query when a certain condition exists. I tried the query below but am getting a syntax error.
SELECT *
FROM contact_details
WHERE contactDeleted` =0
AND IF ( contactVisibility = "private"
, SELECT * FROM contact_details
WHERE contactUserId = 1
, IF( contactVisibility = "group"
, SELECT * FROM contact_details
WHERE contactGroup = 3
)
)
If I'm understanding your question correctly (which is difficult with the lack of info you've provided. Sample datasets and expected outcomes are typically helpful), then I don't believe you need IFs at all for what you want. The following will return contacts that are not deleted and who either have (visibility = "private" and userId = 1) OR (visibility = "group" and group = 3)
SELECT *
FROM contact_details
WHERE contactDeleted = 0
AND (
(contactVisibility = "public")
OR
(contactVisibility = "private" AND contactUserId = 1)
OR
(contactVisibility = "group" AND contactGroup = 3)
)
I am assuming you want to use the IF() function and not the statement which is for stored functions..
Refer to this link for more information on that.
Notice that you have put 2 select statements in there, where the custom return values are supposed to be. So you are returning a SELECT *... now notice that in your upper level sql statement you have an AND.. so you basically writing AND SELECT *.. which will give you the syntax error.
Try using .. AND x IN (SELECT *) .. to find if x is in the returned values.
Let me also list this link to make use of an existing and well written answer which may also applicable to your question.
Related
I want to select a bunch distinct records based off a composite key. In SQL I'd write something like this:
SELECT * FROM security WHERE (
exchange_code = 'exchange_code_1' AND code = 'code_1')
OR (exchange_code = 'exchange_code_2' AND code = 'code_2')
...
OR (exchange_code = 'exchange_code_N' AND code = 'code_N')
)
With SQLAlchemy I'd like to use the filter clause like:
query = sess.query(Security)
[query.filter(
and_(Security.exchange_code == security.exchange_code,
Security.code == security.code)
) for security in securities]
result = query.all()
The problem is filter and where join clauses with an AND not an OR... is there some way to use filter with OR?
Or is my only choice to generate a bunch of individual select's and UNION them? Something like:
first = exchanges.pop()
query = reduce(lambda query, exchange: query.union(exchange.pk_query),
first.pk_query())
query.all()
Use or_:
query = sess.query(Security).filter(
or_(*(and_(Security.exchange_code == security.exchange_code,
Security.code == security.code)
for security in securities)))
If your database supports it, you should use tuple_ instead.
I have a multi-table SQL query.
My need is: The query should I generate a single line by 'etablissement_id' ... and all information that I want to be back in the same query.
The problem is that this query is currently on a table where "establishment" may have "multiple photos" and suddenly, my query I currently generates several lines for the same id...
I want the following statement - LEFT JOINetablissementContenuMultimediaON etablissement.etablissement_id = etablissementContenuMultimedia.etablissementContenuMultimedia_etablissementId - only a single multimedia content is displayed. Is it possible to do this in the query below?
Here is the generated query.
SELECT DISTINCT `etablissement`. * , `etablissementContenuMultimedia`. * , `misEnAvant`. * , `quartier`. *
FROM `etablissement`
LEFT JOIN `etablissementContenuMultimedia` ON etablissement.etablissement_id = etablissementContenuMultimedia.etablissementContenuMultimedia_etablissementId
LEFT JOIN `misEnAvant` ON misEnAvant.misEnAvant_etablissementId = etablissement.etablissement_id
LEFT JOIN `quartier` ON quartier_id = etablissement_quartierId
WHERE (
misEnAvant_typeMisEnAvantId =1
AND (
misEnAvant_dateDebut <= CURRENT_DATE
AND CURRENT_DATE <= misEnAvant_dateFin
)
)
AND (
etablissement_isActive =1
)
ORDER BY `etablissement`.`etablissement_id` ASC
LIMIT 0 , 30
Here is the code used ZF
public function find (){
$db = Zend_Db_Table::getDefaultAdapter();
$oSelect = $db->select();
$oSelect->distinct()
->from('etablissement')
->joinLeft('etablissementContenuMultimedia', 'etablissement.etablissement_id = etablissementContenuMultimedia.etablissementContenuMultimedia_etablissementId')
->joinLeft('misEnAvant', 'misEnAvant.misEnAvant_etablissementId = etablissement.etablissement_id')
->joinLeft('quartier', 'quartier_id = etablissement_quartierId ')
->where ('misEnAvant_typeMisEnAvantId = 1 AND (misEnAvant_dateDebut <= CURRENT_DATE AND CURRENT_DATE <= misEnAvant_dateFin) ')
->where ('etablissement_isActive = 1')
->order(new Zend_Db_Expr('RAND()'));
$zSql = $oSelect->__toString();
if(isset($_GET['debug']) AND $_GET['debug'] == 1)
echo $zSql ;
//die();
$oResultEtablissement = $db->fetchAll($oSelect);
return $oResultEtablissement ;
}
Can you help me?
Sincerely,
If you are looking to have only one of the media displayed out of many regardless of which it may be then you can just add a limit to the query? After that you can tweak the query for ASCending or DESCending perhaps?
Is this query supposed to have images (or image as it were) for one establishment, or one image each for each active establishment? I see you have a limit 0,30 which means you're likely paginating....
If the result you want is a search for only one establishment, and the first image it comes to would work fine .. just use "limit 1" and you'll only get one result.
I took the time to redo the whole model of the database ... and now it works. There was no solution for a system as flawed
Presently troubleshooting a problem where running this SQL query:
UPDATE tblBenchmarkData
SET OriginalValue = DataValue, OriginalUnitID = DataUnitID,
DataValue = CAST(DataValue AS float) * 1.335
WHERE
FieldDataSetID = '6956beeb-a1e7-47f2-96db-0044746ad6d5'
AND ZEGCodeID IN
(SELECT ZEGCodeID FROM tblZEGCode
WHERE(ZEGCode = 'C004') OR
(LEFT(ZEGParentCode, 4) = 'C004'))
Results in the following error:
Msg 8114, Level 16, State 5, Line 1
Error converting data type nvarchar to float.
The really odd thing is, if I change the UPDATE to SELECT to inspect the values that are retrieved are numerical values:
SELECT DataValue
FROM tblBenchmarkData
WHERE FieldDataSetID = '6956beeb-a1e7-47f2-96db-0044746ad6d5'
AND ZEGCodeID IN
(SELECT ZEGCodeID
FROM tblZEGCode WHERE(ZEGCode = 'C004') OR
(LEFT(ZEGParentCode, 4) = 'C004'))
Here are the results:
DataValue
2285260
1205310
Would like to use TRY_PARSE or something like that; however, we are running on SQL Server 2008 rather than SQL Server 2012. Does anyone have any suggestions? TIA.
It would be helpful to see the schema definition of tblBenchmarkData, but you could try using ISNUMERIC in your query. Something like:
SET DataValue = CASE WHEN ISNUMERIC(DataValue)=1 THEN CAST(DataValue AS float) * 1.335
ELSE 0 END
Order of execution not always matches one's expectations.
If you set a where clause, it generally does not mean the calculations in the select list will only be applied to the rows that match that where. SQL Server may easily decide to do a bulk calculation and then filter out unwanted rows.
That said, you can easily write try_parse yourself:
create function dbo.try_parse(#v nvarchar(30))
returns float
with schemabinding, returns null on null input
as
begin
if isnumeric(#v) = 1
return cast(#v as float);
return null;
end;
So starting with your update query that's giving an error (please forgive me for rewriting it for my own clarity):
UPDATE B
SET
OriginalValue = DataValue,
OriginalUnitID = DataUnitID,
DataValue = CAST(DataValue AS float) * 1.335
FROM
dbo.tblBenchmarkData B
INNER JOIN dbo.tblZEGCode Z
ON B.ZEGCodeID = Z.ZEGCodeID
WHERE
B.FieldDataSetID = '6956beeb-a1e7-47f2-96db-0044746ad6d5'
AND (
Z.ZEGCode = 'C004' OR
Z.ZEGParentCode LIKE 'C004%'
)
I think you'll find that a SELECT statement with exactly the same expressions will give the same error:
SELECT
OriginalValue,
DataValue NewOriginalValue,
OriginalUnitID,
DataUnitID OriginalUnitID,
DataValue,
CAST(DataValue AS float) * 1.335 NewDataValue
FROM
dbo.tblBenchmarkData B
INNER JOIN dbo.tblZEGCode Z
ON B.ZEGCodeID = Z.ZEGCodeID
WHERE
B.FieldDataSetID = '6956beeb-a1e7-47f2-96db-0044746ad6d5'
AND (
Z.ZEGCode = 'C004' OR
Z.ZEGParentCode LIKE 'C004%'
)
This should show you the rows that can't convert:
SELECT
B.*
FROM
dbo.tblBenchmarkData B
INNER JOIN dbo.tblZEGCode Z
ON B.ZEGCodeID = Z.ZEGCodeID
WHERE
B.FieldDataSetID = '6956beeb-a1e7-47f2-96db-0044746ad6d5'
AND (
Z.ZEGCode = 'C004' OR
Z.ZEGParentCode LIKE 'C004%'
)
AND IsNumeric(DataValue) = 0
-- AND IsNumeric(DataValue + 'E0') = 0 -- try this if the prior doesn't work
The trick in the last commented line is to tack on things to the string to force only valid numbers to be numeric. For example, if you wanted only integers, IsNumeric(DataValue + '.0E0') = 0 would show you those that aren't.
I have a somewhat complex mySQL query I am trying to execute. I have two parameters: facility and isEnabled. Facility can have a value of "ALL" or be specific ID. isEnabled can have value of "ALL" or be 0/1.
My issue is that I need to come up with logic that can handle the following scenarios:
1) Facility = ALL AND isEnabled = ALL
2) Facility = ALL AND isEnabled = value
3) Facility = someID AND isEnabled = ALL
4) Facility = someID AND isEnabled = value
The problem is that I have several nested IF statements:
IF (Facility = 'ALL') THEN
IF (isEnabled = 'ALL') THEN
SELECT * FROM myTable
ELSE
SELECT * FROM myTable
WHERE isEnabled = value
END IF;
ELSE
IF (isEnabled = 'ALL') THEN
SELECT * FROM myTable
WHERE facility = someID
ELSE
SELECT * FROM myTable
WHERE facility = someID AND isEnabled = value
END IF;
END IF;
I would like to be able to combine the logic in the WHERE clause using either a CASE statement or Conditional's (AND/OR) but I am having trouble wrapping my head around it this morning. Currently the query is not performing as it is expected to be.
Any insight would be helpful!
Thanks
You could do this...
SELECT
*
FROM
myTable
WHERE
1=1
AND (facility = someID OR Facility = 'ALL')
AND (isEnabled = value OR isEnabled = 'ALL')
However, this yields a poor execution plan - it's trying to find one size fits all, but each combination of parameters can have different plans depending on data, indexes, etc.
This means that it is better to build the query dynamically
SELECT
*
FROM
myTable
WHERE
1=1
AND facility = someID -- Only include this line if : Facility = 'ALL'
AND isEnabled = value -- Only include this line if : isEnabled = 'ALL'
I know it can feel dirty to use dynamic queries, but this is a good corner case as to when then really can excel. I'll go find a spectacularly informative link for you now. (It's a lot to read, but it's very worth learning from)
Link : Dynamic Search
How do I do this
Select top 10 Foo from MyTable
in Linq to SQL?
Use the Take method:
var foo = (from t in MyTable
select t.Foo).Take(10);
In VB LINQ has a take expression:
Dim foo = From t in MyTable _
Take 10 _
Select t.Foo
From the documentation:
Take<TSource> enumerates source and yields elements until count elements have been yielded or source contains no more elements. If count exceeds the number of elements in source, all elements of source are returned.
In VB:
from m in MyTable
take 10
select m.Foo
This assumes that MyTable implements IQueryable. You may have to access that through a DataContext or some other provider.
It also assumes that Foo is a column in MyTable that gets mapped to a property name.
See http://blogs.msdn.com/vbteam/archive/2008/01/08/converting-sql-to-linq-part-7-union-top-subqueries-bill-horst.aspx for more detail.
Use the Take(int n) method:
var q = query.Take(10);
The OP actually mentioned offset as well, so for ex. if you'd like to get the items from 30 to 60, you would do:
var foo = (From t In MyTable
Select t.Foo).Skip(30).Take(30);
Use the "Skip" method for offset.
Use the "Take" method for limit.
#Janei: my first comment here is about your sample ;)
I think if you do like this, you want to take 4, then applying the sort on these 4.
var dados = from d in dc.tbl_News.Take(4)
orderby d.idNews descending
select new
{
d.idNews,
d.titleNews,
d.textNews,
d.dateNews,
d.imgNewsThumb
};
Different than sorting whole tbl_News by idNews descending and then taking 4
var dados = (from d in dc.tbl_News
orderby d.idNews descending
select new
{
d.idNews,
d.titleNews,
d.textNews,
d.dateNews,
d.imgNewsThumb
}).Take(4);
no ? results may be different.
This works well in C#
var q = from m in MyTable.Take(10)
select m.Foo
Whether the take happens on the client or in the db depends on where you apply the take operator. If you apply it before you enumerate the query (i.e. before you use it in a foreach or convert it to a collection) the take will result in the "top n" SQL operator being sent to the db. You can see this if you run SQL profiler. If you apply the take after enumerating the query it will happen on the client, as LINQ will have had to retrieve the data from the database for you to enumerate through it
I do like this:
var dados = from d in dc.tbl_News.Take(4)
orderby d.idNews descending
select new
{
d.idNews,
d.titleNews,
d.textNews,
d.dateNews,
d.imgNewsThumb
};
You would use the Take(N) method.
Taking data of DataBase without sorting is the same as random take
Array oList = ((from m in dc.Reviews
join n in dc.Users on m.authorID equals n.userID
orderby m.createdDate descending
where m.foodID == _id
select new
{
authorID = m.authorID,
createdDate = m.createdDate,
review = m.review1,
author = n.username,
profileImgUrl = n.profileImgUrl
}).Take(2)).ToArray();
I had to use Take(n) method, then transform to list, Worked like a charm:
var listTest = (from x in table1
join y in table2
on x.field1 equals y.field1
orderby x.id descending
select new tempList()
{
field1 = y.field1,
active = x.active
}).Take(10).ToList();
This way it worked for me:
var noticias = from n in db.Noticias.Take(6)
where n.Atv == 1
orderby n.DatHorLan descending
select n;