Probably something really trivial but I haven't quite found the answer I am looking for on the internet and I get syntax errors with this. What I want/need to do is to provide a special case in my where clause where the doctype is 1. If it is, then it needs to match the claimID from a sub select of a temp table. If the doctype is not a 1 then we just need to continue on and ignore the select.
AND
CASE
WHEN #DocType = 1 THEN (c.ClaimID IN (SELECT TNE.ClaimID FROM TNE)
END
I have seen some for if statements but I didn't seem to get that to work and haven't found anything online as of yet that shows a case statement doing what I would like. Is this even possible?
You don't need a case statement, you could do:
AND (#DocType <> 1 or c.ClaimID in (SELECT TNE.ClaimID FROM TNE))
A CASE expression (not statement) returns a single value. SQL Server supports the bit data type. (Valid values are 0, 1, 'TRUE' and 'FALSE'.) There is a boolean data type (with values TRUE, FALSE and UNKNOWN), but you cannot get a firm grip on one. Your CASE expression attempts to return a boolean, give or take the unmatched parenthesis, which is not supported in this context.
You could use something like this, though Luc's answer is more applicable to the stated problem:
and
case
when #DocType = 1 and c.ClaimId in ( select TNE.ClaimId from TNE ) then 1
when #DocType = 2 and ... then 1
...
else 0
end = 1
Note that the CASE returns a value which you must then compare (= 1).
Related
I have a query in postgresql where I want to append a minus sign to the transactions.amount field when the transaction.type = 2 (which refers to withdrawals). I am trying to concat a minus sign and the transactions.amount field which is an int. I casted the transactions.amount field to a text/varchar but no matter what I still get the error, "PostgreSql Error: case types numeric and text cannot be matched"
Here is the query I am running,
SELECT CAST(CASE WHEN "IsVoided" IS TRUE THEN 0
WHEN "Transactions"."TransactionType" = 2
THEN CONCAT('-', CAST("Transactions"."Amount" AS TEXT))
ELSE "Transactions"."Amount" END AS Text) AS "TransAmount"
FROM "Transactions"
LEFT JOIN "DepositSources"
ON "Transactions"."DepositSourceId" =
"DepositSources"."DepositSourceId"
LEFT JOIN "WithdrawalSources"
ON "Transactions"."WithdrawalSourceId" =
"DepositSources"."DepositSourceId"
WHERE "Transactions"."FundId" = 4
AND "Transactions"."ReconciliationId" = 24
What's very perplexing is when i run the below query it works as expected,
SELECT CONCAT('-', CAST("Transactions"."Amount" AS TEXT)) FROM
"Transactions"
All branches of a CASE expression need to have the same type. In this case, you're stuck with making all branches text, because what follows THEN can only be text. Try this version:
CASE WHEN IsVoided IS TRUE
THEN '0'
WHEN Transactions.TransactionType = 2
THEN CONCAT('-', Transactions.Amount::text)
ELSE Transactions.Amount::text END AS TransAmount
Note that it is unusual to be using the logic you have in a CASE expression. Typically, you would just be checking the values of a single column, not multiple different columns.
Edit:
It appears that your call to CONCAT mainly serves to negative a value. Here is one more simple way to do this:
CASE WHEN IsVoided IS TRUE
THEN 0
WHEN Transactions.TransactionType = 2
THEN -1.0 * Transactions.Amount
ELSE Transactions.Amount END AS TransAmount
In this case, we can make the CASE expression just generate numeric output, which might be really what you are after.
I have field that has up to 9 comma separated values each of which have a string value and a numeric value separated by colon. After parsing them all some of the values between 0 and 1 are being set to an integer rather than a numeric as cast. The problem is obviously related to data type but I am unsure what is causing it or how to fix it. The problem only exists in the case statement, the split_part function seems to be working perfect.
Things I have tried:
nvl(split_part(one,':',2),0) = COALESCE types text and integer cannot be matched
nvl(split_part(one,':',2)::numeric,0) => Invalid input syntax for type numeric
numerous other cast/convert variations
(CASE WHEN split_part(one,':',2) = '' THEN 0::numeric ELSE split_part(one,':',2)::numeric END)::numeric => runs but get int value of 0
When using the split_part function outside of case statement it does work correctly. However, I need the result to be zero for null values.
split_part(one,':',2) => 0.02068278096187390979 (expected result)
When running the code above I get zero but expect 0.02068278096187390979
Field "one" has the following value 'xyz: 0.02068278096187390979' before the split_part function.
EXAMPLE:
create table test(one varchar);
insert into test values('XYZ: 0.50000000000000000000')
select
one ,split_part(one,':',2) as correct_value_for_those_that_are_not_null ,
case
when split_part(one,':',2) = '' then null
else split_part(one,':',2)::numeric
end::numeric as this_one_is_the_problem
from test
However, I need the result to be zero for null values.
Your example does not deal with NULL values at all, though. Only addressing the empty string ('').
To replace either with 0 reliably, efficiently and without casting issues:
SELECT part1, CASE WHEN part2 <> '' THEN part2::numeric ELSE numeric '0' END AS part2
FROM (
SELECT split_part(one, ':', 1) AS part1
, split_part(one, ':', 2) AS part2
FROM test
) sub;
See:
Best way to check for "empty or null value"
Also note that all SQL CASE branches must agree on a common data type. There have been minor adjustments in the logic that determines the resulting type in the past, so the version of Postgres may play a role in corner cases. Don't recall the details now.
nvl()is not a Postgres function. You probably meant COALESCE. The manual:
This SQL-standard function provides capabilities similar to NVL and IFNULL, which are used in some other database systems.
I wrote this snippet of code here in Oracle SQL Developer but I don't know how to use a CASE WHEN so that when k.QUARANTINED = 0, display 'No', else if k.QUARANTINED = 1 display 'Yes'. This column is always 0 or 1.
select
s.NAME as "Shipment ID"
,k.STATUS_ID as "Status"
,k.EXPIRATION
,k.DISDATE
,u.SCR_NO as "Patient No"
,k.QUARANTINED
,k.PREVIOUS_STATUS_ID
,k.SORT_KEY as "Sort Order"
from KIT k
left join SHIPMENT s on s.ID = k.SHIPMENT_ID
left join USR u on u.PAT_ID = k.PAT_ID;
I tried a couple of times but kept getting errors most likely since I don't know how write the syntax correctly or maybe I have to rewrite this completely differently? I'd like to keep the order of the columns the same. I just would like to see 'Yes' or 'No' for k.Quarantined instead of 0 or 1 returned in the result. :)
SELECT
S.name AS "shipment ID",
K.status_id AS "status",
K.expiration,
K.disdate,
U.scr_no AS "Patient No",
K.quarantined,
CASE k.quarantined
WHEN 0 THEN 'No'
WHEN 1 THEN 'Yes'
ELSE 'Missing or Null'
END AS "quarantine status case example 1",
CASE
WHEN k.quarantined = 0
THEN 'No'
WHEN k.quarantined = 1
THEN 'Yes'
ELSE 'Missing or Null'
END AS "quarantine status case example 2",
K.previous_status_id,
K.sort_key AS "sort order",
FROM Kit K
LEFT JOIN Shipment S
ON K.shipment_id = S.id
LEFT JOIN USR U
ON K.pat_id = U.pat_id
ORDER BY
K.sort_key ASC
;
Two examples of CASE above. The first example is used when you are evaluating a single column/variable.
The second example is used for testing multiple conditions.
When using the second example of CASE statements, it is important to understand that CASE will return the result for the first condition that evaluates TRUE. When using complex logic, sometimes a developer may (inadvertently) have overlapping logic where multiple conditions can be satisfied. When unexpected results from CASE occur, it is important to go back and reevaluate the statement from the top down.
If you are absolutely sure that K.quarantined cannot be NULL and it can only be 0 or one (research the table DDL for check constraints) then you can remove or comment out the ELSE clause on the CASE statements--but it is generally good practice to always have an ELSE clause for consistency. You can have it simply state "ELSE NULL" if you do not ever expect anything other than what's described in your CASE statement.
Lastly, be sure to make sure to identify whether K.quarantined is numeric or text (check table DDL). If it is actually storing text '0' or '1', then should change your literals accordingly--although I think current versions of Oracle are smart enough to do the implicit conversions for you.
I have a SELECT object which contains a WHERE.
I can return the WHERE using getPart(Zend_Db_Select::WHERE), this returns something like this:
array
0 => string "(clienttype = 'agent')"
1 => string "AND (nextpayment < (NOW() - INTERVAL 1 DAY))"
This array seems pretty useless as I cannot do this with it
$client->update(array("paymentstatus" => "lapsed"), $where);
Or even put it into another SELECT object. Is there a way of getting a more useful representation of the WHERE statement from the SELECT object?
Thanks
EDIT
The best I have come up with so far is
$where = new Zend_Db_Expr(implode(" ", $select->getPart(Zend_Db_Select::WHERE)));
Your first choice, $client->update(...) would work, if getParts omitted the 'AND' from the second part of the where clause.
I'm pretty sure your only choice is to:
use your second option (probably safest depending on how complex the where clauses are) -or-
iterate through the $where returned and remove the leading 'AND', 'OR' that may exist.
I have a table with a varchar column, and I want to find values that match a certain number. So lets say that column contains the following entries (except with millions of rows in real life):
123456789012
2345678
3456
23 45
713?2
00123456789012
So I decide I want all the rows which are numerically 123456789012 write a statement that looks something like this:
SELECT * FROM MyTable WHERE CAST(MyColumn as bigint) = 123456789012
It should return the first and last row, but instead the whole query blows up because it can't convert the "23 45" and "713?2" to bigint.
Is there another way to do the conversion that will return NULL for values that can't convert?
SQL Server does NOT guarantee boolean operator short-circuit, see On SQL Server boolean operator short-circuit. So all solution using ISNUMERIC(...) AND CAST(...) are fundamentally flawed (they may work, but hey can arbitrarily fail later dependiong on the generated plan). A better solution is using CASE, as Thomas suggests: CASE ISNUMERIC(...) WHEN 1 THEN CAST(...) ELSE NULL END. But, as gbn pointed out, ISNUMERIC is notoriously finicky in identifying what 'numeric' means and many cases where one would expect it to return 0 it returns 1. So mixing the CASE with the LIKE:
CASE WHEN MyRow NOT LIKE '%[^0-9]%' THEN CAST(MyRow as bigint) ELSE NULL END
But the real problem is that if you have millions of rows and you have to search them like this, you'll always end up scanning end-to-end since the expression is not SARG-able (no matter how we rewrite it). The real issue here is data purity, and should be addressed at the appropriate level, where the data is populated. Another thing to consider is if is possible to create a persisted computed column with this expression and create a filtered index on it which eliminates NULL (ie. non-numeric). That would speed up things a little.
If you are using SQL Server 2012 you can use the 2 new methods:
TRY_CAST()
TRY_CONVERT()
Both methods are equivalent. They return a value cast to the specified data type if the cast succeeds; otherwise, returns null. The only difference is that CONVERT is SQL Server specific, CAST is ANSI. using CAST will make your code more portable (although not sure if any other database provider implements TRY_CAST)
ISNUMERIC will accept empty string and values like 1.23 or 5E-04 so could be unreliable.
And you don't know what order things will be evaluated in so it could still fail (SQL is declarative, not procedural, so the WHERE clause probably won't be evaluated left to right)
So:
you want to accept value that consist only of the characters 0-9
you need to materialise the "number" filter so it's applied before CAST
Something like:
SELECT
*
FROM
(
SELECT TOP 2000000000 *
FROM MyTable
WHERE MyColumn NOT LIKE '%[^0-9]%' --double negative rejects anything except 0-9
ORDER BY MyColumn
) foo
WHERE
CAST(MyColumn as bigint) = 123456789012 --applied after number check
Edit: quick example that fails.
CREATE TABLE #foo (bigintstring varchar(100))
INSERT #foo (bigintstring )VALUES ('1.23')
INSERT #foo (bigintstring )VALUES ('1 23')
INSERT #foo (bigintstring )VALUES ('123')
SELECT * FROM #foo
WHERE
ISNUMERIC(bigintstring) = 1
AND
CAST(bigintstring AS bigint) = 123
SELECT *
FROM MyTable
WHERE ISNUMERIC(MyRow) = 1
AND CAST(MyRow as float) = 123456789012
The ISNUMERIC() function should give you what you need.
SELECT * FROM MyTable
WHERE ISNUMERIC(MyRow) = 1
AND CAST(MyRow as bigint) = 123456789012
And to add a case statement like Thomas suggested:
SELECT * FROM MyTable
WHERE CASE(ISNUMERIC(MyRow)
WHEN 1 THEN CAST(MyRow as bigint)
ELSE NULL
END = 123456789012
http://msdn.microsoft.com/en-us/library/ms186272.aspx
SELECT *
FROM MyTable
WHERE (ISNUMERIC(MyColumn) = 1) AND (CAST(MyColumn as bigint) = 123456789012)
Additionally you can use a CASE statement in order to get null values.
SELECT
CASE
WHEN (ISNUMERIC(MyColumn) = 1) THEN CAST(MyColumn as bigint)
ELSE NULL
END AS 'MyColumnAsBigInt'
FROM tableName
If you require additional filtering, for numerics which are not valid to be cast to bigint, you can use the following instead of ISNUMERIC:
PATINDEX('%[^0-9]%',MyColumn)) = 0
If you need decimal values instead of integers, cast to float instead and change the regex to '%[^0-9.]%'