I want to have an If condition based on a condition obtained from a database. So each row in this table has a condition as a string on when something should be displayed.
Example: the row has the column "DisplayWhen" with the value "Status="M"".
The syntax of the condition statement is vb.net and the variable "Status" is available in the code.
So my statement is:
If CBool(rdr.Item("DisplayWhen").tostring.trim) then
'something
End If
But I keep getting the error: Conversion from string "Status="M"" to type Boolean is not valid.
Any help would be appreciated.
As I said in my comment a string in itself can not evaluated to a Boolean, you need to compare it to your expected value. Something like this.
If CBool(rdr.Item("DisplayWhen").ToString.Trim = "Status=""M""") Then
'something
End If
or using the Equals Method
If rdr.Item("DisplayWhen").Equals("Status=""M""") Then
'something
End If
Related
I need to check whether the values received in a file upload column has exponential or long values.
For example, if value is 5.02E+13 instead of numeric value - 50100434157080 then need to restrict it with a message saying format is incorrect.
For this I pass the upload content from frontend to backend in a temporary table and then get it checked if passed value has exponential value or numeric value.
Tried using T-SQL function isnumeric() but it didn't give me expected result. Any other function available?
Since you mention using isnumeric I assume you are using SQL Server, in which case you can try try_cast, for example
select case when Try_Cast(Column as bigint) is null then 'not integer' else 'integer' end
from table
You could also use like
select case when Column like '%e%' then 'exponent' else 'number' end
from table
CASE
WHEN code IN ('FJS354', 'JDF334')
THEN 'Lower_form'
ELSE 0
END AS format
This returns an error in Redshift
invalid input syntax for integer: "Lower_form"
I know if I change 'Lower_form' to an integer it will work however I want this column to be a string. Is there a way to do this?
I want this column to be a string.
All branches of a case expression must return the same datatype. You are giving two literal values whose datatype is not the same (string vs integer): the database makes the decision to turn them both to integers - which is not what you want.
Rremove the ambiguity by being explicit about the datatype you want to return. That is, make this literal 0 a string:
CASE WHEN code in ('FJS354','JDF334')
THEN 'Lower_form'
ELSE '0'
END as format
SQL IN STOR:
select * from Car_Company where (#id is null or ID=#id)
What is the code corresponding to the next line ( In Linq )
From A IN DB.Company Where (IIF(String.IsNullOrEmpty(TextBox1.Text),a.cNAME=TextBox1.Text)).ToList
I would recommend pulling your string evaluation out of the LINQ statement and evaluating it once then using the evaluated value in your query. Also, if the value is supposed to be a number, but you can't guarantee if the user supplied a number, you need to test it first to make sure that you have a number in order to avoid the casting issue. The LINQ query that you supplied doesn't quite make sense because the where clause returns a string not a true/false result. You need to compare the value with something in the data rows. I think you want something like:
Dim Id As Integer
If Integer.TryParse(TextBox1.Text, Id) Then
Dim Query = From A IN DB.Company Where A.Id = Id
End If
It's totally unclear... Try this...
(From A IN DB.Company Where IF(Not String.IsNullOrEmpty(TextBox1.Text),
A.cNAME=TextBox1.Text,
"Something else")).ToList
I am trying to compare a variable in db 2 sp using like, however it always goes to the else part of the statement, can someone correct the syntax here..here is the part of the code
do
IF(#variable like '%abc') THEN
set #anotherVariable='abc';
ELSEIF (#variable like '%def') THEN
set #anotherVariable='def';
ELSEIF (#variable like '%def') THEN
set #anotherVariable='def';
ELSE
set #anotherVariable='xyz';
END IF;
END FOR;
This code is part of a cursor, query always returns 1 value, however my comparison is not working(incorrect syntax?), it always goes to the last else as if it never was able to match. I know that value is there but its not comparing in this manner...Thanks
Are you writing SQL-PL code? Because variables are referenced directly by its name, not preceded by the '#' sign.
Another thing is that you are using the like operator outside a query. 'Like' is not a function, it is a predicate: http://pic.dhe.ibm.com/infocenter/db2luw/v10r5/topic/com.ibm.db2.luw.sql.ref.doc/doc/r0000751.html
Instead, you can use a 'case' in the select and then return the corresponding value. In that way you do not need to do an 'if-else': http://pic.dhe.ibm.com/infocenter/db2luw/v10r5/topic/com.ibm.db2.luw.sql.ref.doc/doc/r0023458.html
I'm doing a simple query that uses the DateDiff function to find the number of days between the dates. However, with regards to certain instances, I'd like to populate a blank field (not a null).
Something like this is what I currently have, and it seems to work fine (but it populates a null).
[Test (Years)] = CASE WHEN TYPE IN ('A','B')
THEN NULL ELSE IsNull(CONVERT(decimal(28,12),
(DATEDIFF(d,#StartDate,ExpirationDate)))/365,0) END
Now if I try something like this... which tries to convert all TYPE A and B to populate a blank, I'll get the following error message: Error converting data type varchar to numeric.
[Test (Years)] = CASE WHEN TYPE IN ('A','B')
THEN '' ELSE IsNull(CONVERT(decimal(28,12),
(DATEDIFF(d,#StartDate,ExpirationDate)))/365,0) END
Is there a simple thing I'm missing? I've tried doing the calcualtions without converting to a decimal, but it doesn't seem to work. Any ideas? Thanks
CASE is an expression that returns exactly one value and all of the branches must yield compatible types. A string (even a blank string) is not compatible with a decimal, so you need to do something like:
CASE WHEN ... THEN '' ELSE
CONVERT(VARCHAR(32), COALESCE(CONVERT(DECIMAL(23,12), ... ,0)) END
Note that this hack will only work if you are presenting the data to an end user. If you are trying to store this data in a column or use it in other calculations, it too will be tripped up by the blank string. A number can't be a blank string:
DECLARE #i INT = '';
SELECT #i;
Result:
0
So, if you don't want "empty" numerics to be interpreted as 0, stop being afraid of NULL and if you are dealing with this at presentation time, have the presentation layer present a blank string instead of NULL.