I need a variable value, which will compute the value on the basis of condition I have used.
I need to apply if condition and in case that condition exists I need to return the value as 1 else 0
My logic is:
{!field f=temp_close_timing v='[2022-03-11T11:14:39.667679 TO 2022-03-11T11:14:39.667679]'}
If we get the value from the above statement, we need to return true else return false.
I am not sure how to do this. I have tried exists condition here but I am not sure how to right the same in FL
eg:
fl=if((exists({!field f=temp_close_timing v='[2022-03-11T11:14:39.667679 TO 2022-03-11T11:14:39.667679]'}),1,0),1,0)
but here I am getting error as "Error parsing fieldname: Expected identifier at pos 3 str="
I am not sure how to assign variable and if I assign variable that should be indexed separately.
Related
I have tried to use the below statement to check if the value present in the given fieldname for a record is NULL or not, if it is NULL then put 0 else return the value present in the fieldname.
It shows syntax error.
SELECT [structname.fieldname], isnull([structname.fieldname],0) FROM tablename WHERE condition;
Can you please let me know where am I going wrong?
I have also tried the below statement
SELECT [structname.fieldname], CASE WHEN [structname.fieldname] IS NULL THEN 0 ELSE [structname.fieldname] END FROM tablename WHERE condition;
For the above statement, the program crashes when it encounters a NULL value. Can you please tell me how else can I check if a value of a particular record is NULL or not and then read the value if it is not NULL else read it as 0
You are not using correctly the square brackets.
The column names should be written like:
[structname].[fieldname]
assuming that [structname] is the name or the alias of the table where fieldname comes from, and not like:
[structname.fieldname]
which would be ok only if the column's name is actually structname.fieldname.
What you need can be done with the function COALESCE():
SELECT COALESCE([fieldname], 0) FROM tablename
In my SQL Server stored procedure, I want to add a Where clause as dynamic as follows:
AND CASE WHEN #mySt <> '' THEN s.myStatus IN(#mySt) ELSE 0=0 END
When I want to check is: if #mySt is not empty, I want to add s.myStatus IN(#mySt).
If if #mySt is empty, I want to skip this where clause.
I get an error
Incorrect syntax near 'IN'
CASE is an expression, it returns a scalar value not a boolean result; you can't do want you're trying to do as s.myStatus IN(#mySt) isn't a scalar value.
Use proper boolean logic:
AND (s.myStatus = #mySt OR #mySt IS NULL) --I suggest NULL over a blank string
I replaced IN with =, as #mySt is a scalar value, so IN and = would be synonyms.
I have an issue with substring function while using it inside case statement.
select
case when -1<0 then 'ok' else SUBSTRING('abcd',1,-1) end
gives me an issue:
Invalid length parameter passed to the substring function.
Why is the case "looking" at the else condition since the first condition is met?
On the other hand query:
declare #a int;
set #a=-1
select
#a,
case when #a<0 then 'ok' else SUBSTRING('abcd',1,#a) end
presents the right answer 'ok' without any errors.
The problem is that the literal value of -1 is parsed by the compiler before run-time for the length parameter. The compiler knows that -1 is invalid, as length must have a positive value, so the error is flagged before the SQL is even run.
In the latter statement, the length passed is a variable. At compile time, the variable has an "unknown" value, as it's not SET till run time, thus the syntax is fine.
Simply put, the compiler knows that a length of -1 for SUBSTRINGis invalid, regardless of if that SQL will actually run, and so errors.
Unlike other functions, such as STUFF and REPLICATE, which state "If length is negative, a null string is returned.", SUBSTRING, LEFT, and RIGHT all state: "If integer_expression is negative, an error is returned." For a literal value, it appears that the compiler is checking these values, even if they will never be used, and then flagging the error.
This isn't limited to logic within a CASE either. For example, the using logical flow operators such as IF generates the same behaviour:
IF 1 = 0
SELECT LEFT('abc',-1)
As does the ISNULL function:
SELECT ISNULL('ok',RIGHT('abc',-1));
It only, however, occurs with literal values. If, for example, you were to use the values from a column, the behaviour is not seen:
IF 1 = 0
SELECT SUBSTRING('abc',1,n) FROM (VALUES(1),(-1)) V(n);
This does not return an error, even though everything in VALUES is a literal. That is because the value of n has not been evaluated.
You can try this as it needed positive end values as length can not be in negative but can be 0.
select
case when -1 < 0 then 'ok' else SUBSTRING('abcd',1, 1) end
I am using avp_db_query to retrieve my table row, sometimes one field value is null. But when I use if condition it does not follow and move on.
avp_db_query("select status from orders where id = 1", "$avp(status);")
Now if i write condition
if($avp(status)==1){
do success
} else {
do failure
exit();
}
Above condition does not work on failure status and continue, but when I put two if conditions and check if it is equal to one or equal to 0 then it works.
another issue is if this column has null value than nothing work, and it proceeds with giving the following warning.
WARNING:core:comp_scriptvar: invalid EQUAL operation: left is
VARIABLE_ELEMENT/STRING_VAL, right is NUMBER/NO_VAL
You can test for NULL SQL column values with:
if ($avp(status) == "<null>")
... which is equivalent to:
if ($(avp(status)[0]) == "<null>")
It was the only way we could get this to work, given that the $avp(status) = NULL; statement is meant to delete the top-most value in the AVP's stack.
If you are claiming that the else statement is not executed when it should be, please give a minimally viable example, along with the output of opensips -V, possibly opening up a new issue, separately.
Since the following code prints 'First' and 'Second' INSERT that order, can I conclude that the first condition satisfied is ALWAYS executed?
DECLARE #Constant1 int = 1
DECLARE #Constant2 int = 2
select
case
when #Constant1 = 1
then 'First'
when #Constant1 = 1 and #Constant2 = 2
then 'Second'
end as Result
select
case
when #Constant1 = 1 and #Constant2 = 2
then 'Second'
when #Constant1 = 1
then 'First'
end as Result
I know that sometimes parallel processing effects the outcome and I was trying to understand IF this type of situation that I see in Production would always return the same result.
This question is intended to understand if there is a potential issue in production code. If I were going to write the code anew, I think I would try to make the code explicitly mutually exclusive..
select
case
when #Constant1 = 1 and #Constant2 != 2
then 'First'
when #Constant1 = 1 and #Constant2 = 2
then 'Second'
end as Result
The Documentation for CASE states.
Searched CASE expression:
Evaluates, in the order specified, Boolean_expression for each WHEN clause.
Returns result_expression of the first Boolean_expression that evaluates to TRUE.
If no Boolean_expression evaluates to TRUE, the Database Engine returns the else_result_expression if an ELSE clause is specified, or
a NULL value if no ELSE clause is specified.
So it will return the first true branch.
For a simple query such as in the question I would expect it to not evaluate the other branches either.
A few cases where this short circuiting behaviour does not work as expected/advertised are discussed in this DBA site question.
Does SQL Server read all of a COALESCE function even if the first argument is not NULL?
But just to be clear these issues do not affect the left to right precedence order of the result (except for the case when evaluating a later branch causes an error to occur such that no result is returned at all)