I'm getting the "conversion" error in a SQL Select query.
The error is:
Msg 248, Level 16, State 1, Line 6
The conversion of the nvarchar value '7000952682' overflowed an int column.
Problem is, there are no int columns in my table!
Here is the table structure:
Here is the query:
If I set the value of #SU to NULL, then it does return all rows as expected. When the value is set to the string value of '7000952682' I get the error.
Why is SQL Server trying to convert the nvarchar value to an int?
All branches of a CASE expression have to have the same type. In this case (no pun intended), it looks like SQL Server is using an integer type and doing an implicit cast of SU to integer. The problem is that the max value for an integer in SQL Server is roughly 2.1 billion, and the example you gave is using the value 7000952682, hence the overflow.
You have two options here. You could make everything varchar:
CASE WHEN #SU IS NULL OR #SU = '' THEN '1' ELSE [SU] END
Or, you could make everything numeric, using a type that won't overflow, e.g.
CASE WHEN #SU IS NULL OR #SU = ''
THEN CAST(1 AS numeric(20, 6))
ELSE CAST([SU] AS numeric(20, 6)) END
As a side note, you could write the first part of your CASE expression more succinctly using COALESCE:
CASE WHEN COALESCE(#SU, '') = '' THEN '1' ELSE [SU] END
Don't use case in the where clause. The logic is more simply and accurately expressed as:
where (#su is null or #su = '' or #su = su)
Related
I am trying to concatenate two integer values with hyphen in between. So when I try to do the same, SQL gives me the error.
Conversion failed when converting the varchar value '30-45' to data type int.
NOTE:
Also, the second value for concatenation can be null so in that case, a hyphen should not be concatenated.
example
from1 = 30
to1 = 45
case
to1 is null
then from1
else CONCAT(from1, '-' + nullif(to1,'')) end
AS age
//This works but shows 3045 instead of 30-45.
concat(from, '-', to) AS age
//This doesn't work out as it gives the error 'Conversion failed when converting the varchar value '30-45' to data type int.'
Thanks for the help in advance and looking forward to it.
DECLARE #FROM INT=30;
DECLARE #TO INT=45;
SELECT CAST(#FROM AS VARCHAR(2))+'-'+CAST(ISNULL(#TO,'') AS VARCHAR(2));
SQL is trying to convert your phrase to int probably because it's part of CASE statement. It uses the first route to determine the output type.
In your case- you put NULL as the first route option in your CASE, so it is determined as int. try putting instead of it this: CAST(NULL AS VARCHAR(10))
It seems that for some reason you think that strings that contain mathematical expressions are resolved as said expression, not an as literal string. Thus if you have the varchar value '30-45' you think it'll return the int value -15; this isn't true. This in fact isn't true in any language, let alone T-SQL.
For what you have, in your ELSE the '-' isn't a minus... It's a string... - is a minus. If you want to substract a number from another then it's a basic maths expression: a - b. You're effectively doing CONVERT(varchar,a) + '-' + CONVERT(varchar,b)... Just have your ELSE as the following:
from1 - NULLIF(to1,0)
This will return NULL if from1 has the value NULL, or to1 has the value NULL or 0.
Please check below code. It's working
example
#from1 = 30
#to1 = 45
IF #to1 is null
SELECT #from1
ELSE
SELECT CONCAT(#from1, '-' , nullif(#to1,'')) as age
I am trying to compare records between two different SQL tables/databases in my Node project and have to do some transformation in order to compare the values.
In one database (MariaDB) the value is of type INT, and looks like this: 516542
In the other (SQL Server) database the value I need to match to is of type char(21), and looks like this: 00000516542-000
What I tried doing was this:
WHERE (REPLACE(LEFT( LM301.DOCNUMBR, CHARINDEX('-', LM301.DOCNUMBR)), '-', '')) = 516542
This works for some records, but for others I get this error:
"The conversion of the varchar value '0004000009123' overflowed an int
column."
If I pass the first value in as a string ('516542') it doesn't match at all.
How can I handle this scenario?
The error you're getting is at least correct. But from your example i can't determine whether the conversion is right or not.
Basically, somewhere in your CHAR(21). There a value which is greater than int32, or SQL Server int type, in value. This value is: 2,147,483,648. 4,000,009,123 is greater than this max value as specified by the error message.
The DBMS, with this where statement, will try to do the operation and compare to all records, and it runs into an overflow. You could do a string compare instead. Or try an explicit conversion and convert it to bigint.
WHERE CONVERT(BIGINT, (REPLACE(LEFT( LM301.DOCNUMBR, CHARINDEX('-', LM301.DOCNUMBR)), '-', ''))) = 516542
It's doing an implicit cast to INT because that's your compare type, then overflows. Making the conversion explicit allows you to determine the datatype instead.
Basically what's happening:
IF ('21474836480' >= 100) --Implicit conversion: Error and prints false
PRINT 'True'
ELSE
PRINT 'False'
IF ('214748364' >= 100) --Implicit Conversion: True
PRINT 'True'
ELSE
PRINT 'False'
IF (CONVERT(BIGINT, '21474836480') >= 100) --Explicit Conversion: Prints True
PRINT 'True'
ELSE
PRINT 'False'
So wrapping your value in an explicit conversion should resolve your error.
You need to do explicit type conversation with TRY_CONVERT():
TRY_CONVERT(BIGINT, LEFT(LM301.DOCNUMBR, CHARINDEX('-', LM301.DOCNUMBR + '-') - 1)) = 516542
TRY_CONVERT() will return NULL if conversation fail.
You don't need to use replace(), you can subtract the position.
EDIT : Try_CONVERT() is available from 2012 +. For older version you can do :
(CONVERT(BIGINT, LEFT(LM301.DOCNUMBR, CHARINDEX('-', LM301.DOCNUMBR) - 1)) = 516542 AND
CHARINDEX('-', LM301.DOCNUMBR) > 0)
)
Note : This might fail if DOCNUMBR doesn't have numeric value prior to -.
For the love of god can someone please explain me what is going on here.
I am working on some stored procedure bug fixes, after a lot of struggle, I was able to find out where this strange bug is happening so I've made a simple example for the sake of demonstration.
Case 1
DECLARE #test VARCHAR(45) ='0001'
SELECT CASE 0
WHEN -1 THEN ''
WHEN 0 THEN #test
WHEN 1 THEN 12345
END AS 'output'
Case 2
DECLARE #test VARCHAR(45) ='0001'
SELECT CASE 0
WHEN -1 THEN ''
WHEN 0 THEN #test
END AS 'output'
Case 1: output is 1
Case 2: output is 0001 as expected
What happened to the zeros?
strangely it only removes zeros before the number (no matter what number comes at the end), for example DECLARE #test VARCHAR(45) ='1000' works fine, as far case is concerned it is clear that case is zero, if I remove WHEN 0 THEN #test output is null as expected.
Done some research, found only this.
I am using SQL SERVER RC1 2017 as well as SQL SMS.
Thank you for your time.
The difference here is that you have mutliple data types in your THEN/ELSE expressions. In your "CASE 1" you have both int and and varchar datatypes.
int has a higher Data type precedence (Transact-SQL) than a varchar, so the values are returned as an int.
Use the same datatype through out, and this works as you want it to:
DECLARE #test VARCHAR(45) ='0001';
SELECT CASE 0 WHEN -1 THEN ''
WHEN 0 THEN #test
WHEN 1 THEN '12345' --Note that the value in contained in single quotes
END AS [output];
This is because of data type precedence.
The CASE expression documentation says about the returned data type:
Returns the highest precedence type from the set of types in
result_expressions and the optional else_result_expression
Meaning it looks every set of types in the result expressions. Since you have one where the returned data is an INT, then the result of the whole CASE expression is INT (since it has a higher precedence than VARCHAR)
This is happening because the type of the value returned in your last case statement is numeric, so try to change it to
DECLARE #test VARCHAR(45) ='0001'
SELECT CASE 0
WHEN -1 THEN ''
WHEN 0 THEN #test
WHEN 1 THEN '12345'
END AS 'output'
Why the script below returns NULL instead of 0?
DECLARE #number BIGINT = 0;
SELECT NULLIF(#number, '');
According to the MSDN, it should return 0:
NULLIF
Returns a null value if the two specified expressions are equal.
For SQL server, 0 and '' is considered the same (=equal)? What is the logic behind?
When an operator combines two expressions of different data types, the rules for data type precedence specify that the data type with the lower precedence is converted to the data type with the higher precedence.
SELECT CONVERT(bigint, '')
SELECT CONVERT(float, '')
SELECT CONVERT(date, '')
0
0
1900-01-01
https://learn.microsoft.com/en-us/sql/t-sql/data-types/data-type-precedence-transact-sql
As BOL states: "the rules for data type precedence specify that the data type with the lower precedence is converted to the data type with the higher precedence."
You've got two different datatypes, bigint and nvarchar. In order to compare the two, they have to be the same datatype. Following the rule described, the nvarchar is implicitly converted to bigint. Try select convert(bigint, ''), you'll find it results in 0. So they are the same.
This script should return null and it is true!
The reason behind it is '' is a string, so it will get implicitly casted to an integer value when comparing it with an integer as you are doing now!
In general, you're asking for trouble when you're comparing values of different data types, since implicit conversions happen behind the scene.
This is the result of implicit conversion. In some cases a string value can be converted to an integer (such as empty string is converted to 0).
Essentially SQL Server tries to match the data type of the two expressions first, then it checks the values.
DECLARE #number BIGINT = 0;
SELECT
CONVERT(BIGINT, '')
, NULLIF(#number, '')
, NULLIF(#number, CONVERT(BIGINT, ''))
It has converted '' to the integer which is 0, as integer has higher precedence in data type. Check the example below how '' become 0
SELECT CONVERT(INT, '') -- 0
SELECT CAST('' AS INT) -- 0
This is something that has baffled me before but I have never found an explanation for it. I have a column in a SQL Server 2008 database that is of type smallint. I want to look for any rows where the value is NULL or blank, so I say this:
SELECT *
FROM products
WHERE warranty_dom IS NULL
OR warranty_dom = ''
This returns rows with a value of 0
So why is 0 treated as the equivalent of '' ?
0 is not treated as '' per se. Instead, '' is implicitly cast to an integer, and that cast makes it 0.
Try it yourself:
SELECT CAST(0 AS varchar) -- Output: '0'
SELECT CAST('' AS smallint) -- Output: 0
Also, as mentioned elsewhere: If warranty_dom is of type smallint, then it's not possible for it to be blank in the first place.