#RowFrom int
#RowTo int
are both Global Input Params for the Stored Procedure, and since I am compiling the SQL query inside the Stored Procedure with T-SQL then using Exec(#sqlstatement) at the end of the stored procedure to show the result, it gives me this error when I try to use the #RowFrom or #RowTo inside the #sqlstatement variable that is executed.. it works fine otherwise.. please help.
"Must declare the scalar variable "#RowFrom"."
Also, I tried including the following in the #sqlstatement variable:
'Declare #Rt int'
'SET #Rt = ' + #RowTo
but #RowTo still doesn't pass its value to #Rt and generates an error.
You can't concatenate an int to a string. Instead of:
SET #sql = N'DECLARE #Rt int; SET #Rt = ' + #RowTo;
You need:
SET #sql = N'DECLARE #Rt int; SET #Rt = ' + CONVERT(VARCHAR(12), #RowTo);
To help illustrate what's happening here. Let's say #RowTo = 5.
DECLARE #RowTo int;
SET #RowTo = 5;
DECLARE #sql nvarchar(max);
SET #sql = N'SELECT ' + CONVERT(varchar(12), #RowTo) + ' * 5';
EXEC sys.sp_executesql #sql;
In order to build that into a string (even if ultimately it will be a number), I need to convert it. But as you can see, the number is still treated as a number when it's executed. The answer is 25, right?
In your case you can use proper parameterization rather than use concatenation which, if you get into that habit, you will expose yourself to SQL injection at some point (see this and this:
SET #sql = #sql + ' WHERE RowNum BETWEEN #RowFrom AND #RowTo;';
EXEC sys.sp_executesql #sql,
N'#RowFrom int, #RowTo int',
#RowFrom, #RowTo;
You can also get this error message if a variable is declared before a GOand referenced after it.
See this question and this workaround.
Just FYI, I know this is an old post, but depending on the database COLLATION settings you can get this error on a statement like this,
SET #sql = #Sql + ' WHERE RowNum BETWEEN #RowFrom AND #RowTo;';
if for example you typo the S in the
SET #sql = #***S***ql
sorry to spin off the answers already posted here, but this is an actual instance of the error reported.
Note also that the error will not display the capital S in the message, I am not sure why, but I think it is because the
Set #sql =
is on the left of the equal sign.
Sometimes, if you have a 'GO' statement written after the usage of the variable, and if you try to use it after that, it throws such error. Try removing 'GO' statement if you have any.
This is most likely not an answer to the issue itself, but this question pops up as first result when searching for Sql declare scalar variable hence I want to share a possible solution to this error.
In my case this error was caused by the use of ; after a SQL statement. Just remove it and the error will be gone.
I guess the cause is the same as #IronSean already posted in a comment above:
it's worth noting that using GO (or in this case ;) causes a new branch where declared variables aren't visible past the statement.
For example:
DECLARE #id int
SET #id = 78
SELECT * FROM MyTable WHERE Id = #var; <-- remove this character to avoid the error message
SELECT * FROM AnotherTable WHERE MyTableId = #var
Just adding what fixed it for me, where misspelling is the suspect as per this MSDN blog...
When splitting SQL strings over multiple lines, check that that you are comma separating your SQL string from your parameters (and not trying to concatenate them!) and not missing any spaces at the end of each split line. Not rocket science but hope I save someone a headache.
For example:
db.TableName.SqlQuery(
"SELECT Id, Timestamp, User " +
"FROM dbo.TableName " +
"WHERE Timestamp >= #from " +
"AND Timestamp <= #till;" + [USE COMMA NOT CONCATENATE!]
new SqlParameter("from", from),
new SqlParameter("till", till)),
.ToListAsync()
.Result;
Case Sensitivity will cause this problem, too.
#MyVariable and #myvariable are the same variables in SQL Server Man. Studio and will work. However, these variables will result in a "Must declare the scalar variable "#MyVariable" in Visual Studio (C#) due to case-sensitivity differences.
Just an answer for future me (maybe it helps someone else too!). If you try to run something like this in the query editor:
USE [Dbo]
GO
DECLARE #RC int
EXECUTE #RC = [dbo].[SomeStoredProcedure]
2018
,0
,'arg3'
GO
SELECT month, SUM(weight) AS weight, SUM(amount) AS amount
FROM SomeTable AS e
WHERE year = #year AND type = 'M'
And you get the error:
Must declare the scalar variable "#year"
That's because you are trying to run a bunch of code that includes BOTH the stored procedure execution AND the query below it (!). Just highlight the one you want to run or delete/comment out the one you are not interested in.
If someone else comes across this question while no solution here made my sql file working, here's what my mistake was:
I have been exporting the contents of my database via the 'Generate Script' command of Microsofts' Server Management Studio and then doing some operations afterwards while inserting the generated data in another instance.
Due to the generated export, there have been a bunch of "GO" statements in the sql file.
What I didn't know was that variables declared at the top of a file aren't accessible as far as a GO statement is executed. Therefore I had to remove the GO statements in my sql file and the error "Must declare the scalar variable xy" was gone!
As stated in https://learn.microsoft.com/en-us/sql/t-sql/language-elements/sql-server-utilities-statements-go?view=sql-server-ver16 , the scope of a user-defined variable is batch dependent .
--This will produce the error
GO
DECLARE #MyVariable int;
SET #MyVariable = 1;
GO --new batch of code
SELECT #MyVariable--CAST(#MyVariable AS
int);
GO
--This will not produce the error
GO
DECLARE #MyVariable int;
SET #MyVariable = 1;
SELECT #MyVariable--CAST(#MyVariable AS int);
GO
We get the same error when we try to pass a variable inside a dynamic SQL:
GO
DECLARE #ColumnName VARCHAR(100),
#SQL NVARCHAR(MAX);
SET #ColumnName = 'FirstName';
EXECUTE ('SELECT [Title],#ColumnName FROM Person.Person');
GO
--In the case above #ColumnName is nowhere to be found, therefore we can either do:
EXECUTE ('SELECT [Title],' +#ColumnName+ ' FROM Person.Person');
or
GO
DECLARE #ColumnName VARCHAR(100),
#SQL NVARCHAR(MAX);
SET #ColumnName = 'FirstName';
SET #SQL = 'SELECT ' + #ColumnName + ' FROM Person.Person';
EXEC sys.sp_executesql #SQL
GO
Give a 'GO' after the end statement and select all the statements then execute
I'm wondering if it is possible to create a variable name when copying a table to another.
Here's my sort-of algorithm/code
DECLARE #NewTableName VARCHAR(50)
SET #NewTableName = 'MyTable_'+GETDATE() --MyTable_12282010 (for example)
SELECT *
INTO #NewTableName
FROM MyTable
I'm wondering if this is possible. I tried it before, but it failed. Any suggestions guys?
It is possible, but only using dynamic TSQL.
See sp_executesql (or the 2000 version sp_executesql)
Be aware of The Curse and Blessings of Dynamic SQL
I am trying to write a database script (SQL Server 2008) which will copy information from database tables on one server to corresponding tables in another database on a different server.
I have read that the correct way to do this is to use a sql statement in a format similar to the following:
INSERT INTO <linked_server>.<database>.<owner>.<table_name> SELECT * FROM <linked_server>.<database>.<owner>.<table_name>
As there will be several tables being copied, I would like to declare variables at the top of the script to allow the user to specify the names of each server and database that are to be used. These could then be used throughout the script. However, I am not sure how to use the variable values in the actual SQL statements. What I want to achieve is something like the following:
DECLARE #SERVER_FROM AS NVARCHAR(50) = 'ServerFrom'
DECLARE #DATABASE_FROM AS NVARCHAR(50) = 'DatabaseTo'
DECLARE #SERVER_TO AS NVARCHAR(50) = 'ServerTo'
DECLARE #DATABASE_TO AS NVARCHAR(50) = 'DatabaseTo'
INSERT INTO #SERVER_TO.#DATABASE_TO.dbo.TableName SELECT * FROM #SERVER_FROM.#DATABASE_FROM.dbo.TableName
...
How should I use the # variables in this code in order for it to work correctly?
Additionally, do you think my method above is correct for what I am trying to achieve and should I be using NVARCHAR(50) as my variable type or something else?
Thanks
There is probably a better way to do this, but what you are probably trying to do in your example is what's called dynamic SQL where you treat the statement as a string and the execute it. This would be section #2 here:
http://www.mssqltips.com/tip.asp?tip=1160
There are some major downsides to dynamic SQL. You see a couple other approaches that might be better in that article.
If you want to execute a dynamically generated query then you have to use sp_ExecuteSQL
HTH
For the nvarchar(50) - you'd be better using sysname. This is a synonym in SQL Server (for nvarchar(128)) and represents the maximum length of an object identifier.
have a look at http://msdn.microsoft.com/en-us/library/ms188001.aspx - sp_executesql takes a parameter that is a string and executes the sql in that string. so you'd need to concatenate #SERVER_FROM and other params with the INSERT INTO part to make the entire sql statement, and then pass to sp_executesql.
nvarchar(50) is fine, unless your server/database names are longer than that :)
You can create the select statement by concatenating all the information together and then use sp_executesql
so:
sp_executesql 'INSERT INTO ' + #SERVER_TO + '.' + #DATABASE_TO +
'.dbo.TableName SELECT * FROM ' + #SERVER_FROM + '.' +
#DATABASE_FROM+'.dbo.TableName'
I like to make templates for dynamic SQL things like this - it's a lot easier to maintain complex statements and also sometimes easier to handle nested quotes - and definitely easier when terms need to be repeated in multiple places (like column lists):
DECLARE #sql AS nvarchar(max);
SET #sql = 'INSERT INTO {#SERVER_TO}.{#DATABASE_TO}.dbo.TableName
SELECT *
FROM {#SERVER_FROM}.{#DATABASE_FROM}.dbo.TableName'
SET #sql = REPLACE(#sql, '{#SERVER_TO}', QUOTENAME(#SERVER_TO))
SET #sql = REPLACE(#sql, '{#DATABASE_TO}', QUOTENAME(#DATABASE_TO))
SET #sql = REPLACE(#sql, '{#SERVER_FROM}', QUOTENAME(#SERVER_FROM))
SET #sql = REPLACE(#sql, '{#DATABASE_FROM}', QUOTENAME(#DATABASE_FROM))
EXEC(#sql)
I have the following code:
UPDATE myTable
SET Col1 = #Value
However, I have a table that has over a 100 columns and want to be able to specify a column name by passing the name into the query similar to:
UPDATE myTable
SET #ColName = #Value
When I do this I get an error. Is there a good solution to this? Its probably something simple!
Thank you in advanced.
You'll have to use dynamic SQL, and write it to make sure you don't let Little Bobby Tables in. Something like this:
DECLARE #sql NVARCHAR(500)
SET #sql = N'UPDATE myTable SET ' + QUOTENAME(#colName) + ' = #pUpdateVal'
EXEC sp_ExecuteSQL #sql, '#pUpdateVal NVARCHAR(20)', #value
Make sure you change the type of #pUpdateVal to something appropriate for your environment, but this will mitigate the risk of injection attacks.
You'd have to revert to dynamic SQL to do this.
Agreed with the others, you'll need dynamic SQL for this; you can't define object names at run time in native SQL. For a full discussion on dynamic SQL see http://www.sommarskog.se/dynamic_sql.html
I would like to create a function that returns a concatinated string of a given field of given query. Here is what I did.
And this one gives me an error.
Must declare the table variable "#qry".
CREATE FUNCTION dbo.testing
(
#qry varchar(1000),
#fld varchar(100),
#separator varchar(15) = '; '
)
RETURNS varchar
AS
BEGIN
DECLARE #rslt varchar(1000)
SET #rslt =''
SELECT #rslt = #rslt + #separator + CAST(#fld as varchar(160)) FROM #qry
RETURN #rslt
END
What I am trying to do is pass a query to this function and receive a concatinated string for certain field of the query.
Is this possible?
What am I doing wrong?
EDIT: BTW I have MSSQL Server 2005;
If you want to pass through any form of dynamic SQL, you need to execute it via EXEC or (preferred) sp_ExecuteSQL. Make sure your code's not subject to any injection attacks if you're using dynamic SQL as well lest you suffer the wrath of little Bobby Tables :-)
You can't do a FROM #variable. You'd have to use dynamic SQL and make your #qry a derived table or something of that nature. However, I think that's really not the best approach. I believe this is what you're trying to do:
http://geekswithblogs.net/mnf/archive/2007/10/02/t-sql-user-defined-function-to-concatenate-column-to-csv-string.aspx
Make sure to read the comments on the XML alternative solution as well.