I'm currently having trouble writing a stored procedure and setting the value of a variable of type int to the results of a select statement with a variable as the tablename. I've looked at old threads and tried multiple methods, but no luck. If I'm not getting an error regarding the tablename, I end up getting an error with a variable conversion issue. I've been working on this for too long and any help would be appreciated. Below is a portion of my code. Thanks
DECLARE #BATCHNUMBER VARCHAR --value set in earlier code
DECLARE #ETABLE VARCHAR(50); --the table name
DECLARE #FIRSTDOCID INT;
SET #ETABLE = 'tablename_' + #BATCHNUMBER; --CREATE FIRST TABLE NAME
SELECT #FIRSTDOCID = MIN(D0CID) FROM #ETABLE
The error I get is: Must declare the table variable "#ETABLE"
You are trying to select from a VARCHAR, not a table. The only way to make this work is by using Dynamic SQL.
DECLARE #SQL NVARCHAR(250);
SET #SQL = 'SELECT #OUTPUT = MIN(D0CID) FROM ' + QuoteName(#ETABLE);
EXEC sp_executeSql #SQL, N'#output INT OUTPUT', #FIRSTDOCID OUTPUT;
SELECT #FIRSTDOCID;
However, I would not suggest using Dynamic SQL as this often leads to SQL injection.
You'll probably have to do something like use exec if you're dynamically building the query:
SET #QUERY = "SELECT" + ...etc.
exec(#QUERY)
Since ETABLE is a varchar, and not, as expected, a 'table variable'.
Related
I'm creating a report using sql scripts through management studio and I'm getting the error " Must Declare the scalar variable "#Account". I've been reading other similar questions on this portal but they are related to c#
I'm currently trying to reduce the code on the script so I decided to put a sql script into a variable because depending on a condition the where condition will change. Below is an example of the code
Declare #Account int = 1 , #SQL varchar(max)=''
Select #SQL = N'Select ColumnA,ColumnB, ColumnC from Table1 where ColumnA =1'
if #Account IS NULL
Begin
exec(#SQL)
end
--Here is where the error is hapening
else
begin
--This is the line causing the error
Select #SQL = #SQL + 'AND ColumnB=#Account"
exec(#SQL)
end
If I type manually the value of the variable next to "ColumnB=" it works but the account number will be selected by the user executing the script. I'm thinking on maybe building a temp table to capture the variable value and then do a sub query on the where condition but maybe the solution to this error may be more easier
You want sp_executesql:
select #SQL = #SQL + 'AND ColumnB=#Account';
exec sp_executesql #SQL, N'#Account int', #Account=#Account;
This is how you pass parameters into a dynamic SQL statement in SQL Server. I strongly recommend that you only use sp_executesql to execute SQL statements -- even when you don't have parameters. Using it makes it easy to implement parameters when you need them.
You are passing in '#Account' into the #SQL variable -- the underlying EXEC cannot see that variable.
One way of fixing this would instead be to do this:
Select #SQL = #SQL + 'AND ColumnB=' + CAST(#Account as varchar)
Assume I have the following SQL snippet in SQL Server 2012:
DECLARE #fname varchar(20), #strVarName varchar(50)
SET #fname = 'cronus'
SET #strVarName = COVERT_VARIABLE_TO_STRING_NAME ( #fname)
--this should return '#fname'. this is not a value conversion this is converting a variable name to a string name
SELECT #strVarName
How do I do this?
SQL Server does not support reflection. You may be able to retrieve column or table names from its catalog views but with variables you're out of luck. Maybe you'll find another way to solve this issue with dynamic SQL.
Use dynamic sql query
DECLARE #fname varchar(20), #sql varchar(MAX)
SET #fname = 'cronus'
SET #sql = 'SELECT ' + #fname
EXEC (#sql)
There are following Character data types used to store character strings:
char,
varchar,
nvarchar,
text,
If u already used variable as String then why need to convert as a string
DECLARE #fname varchar(20), #strVarName varchar(50)
SET #fname = 'cronus'
SET #strVarName = #fname
SELECT #strVarName
if needed use CAST and CONVERT function
This is such a bizarre question, sounds like something I'd try to do.
Hmm, SQL is not supposed to do this but I guess, it doesn't mean you can't make it.
I think you would effectively have to write your own process to pull this off, something along the lines of:
Create dbo.sProcInserts stored procedure to insert values into a table:
Takes VariableName, Value and possibly table name to insert into as parameters
Create dbo.sProcExec stored procedure to execute stored procedure:
Before execute, read stored procedure into a variable
Find all variables that are SET (i.e. they have a SET #Var = OR SELECT #Var =)
After each variable set, add to your string a line that calls dbo.sProcInserts with the name of the variable and a select #Variable
Execute your newly written stored procedure
That way you don't have to actually make any modifications to your sProcs and it should catch the flow of variables and their changes through your procedure
However the requirement itself is a bit strange for me, but here is a way that could be a good start point for you:
declare #var1 int
Set #var1= 1
--some code here
declare #var2 nvarchar(max)
set #var2 = 10
--some other code here
declare #var3 bit
print ##VERSION
print 'this is fake #value inside a string'
--$ This is a Hint to help me find the Query that should parsed
declare #sql varbinary(max)
select #sql=sql_handle
from sys.sysprocesses
where spid=56
declare #q nvarchar(max)
select #q= substring(text,1,charindex('$',text)-3) from sys.dm_exec_sql_text(#sql)
Select distinct rtrim(ltrim(substring(Name,1,charindex(' ',Name)))) as Name from(
Select substring(replace(Name,'=',' '),8, Len(Name)) as Name from dbo.SplitString(#q,'declare ')
) as K
where Name like '#[^#]%'
By running the above query you will get the variables name.
Output:
#var1
#var2
#var3
You can find the source code for SplitString function Here
Note: If you are using SQL Server 2016 and your database's compatibility level is equal or greater than 130, you can also use SPLIT_STRING introduced by Microsoft it self. Learn more Here
This may be an easy answer but I've been staring at it for too long...
I have the following query that takes a stored procedure input parameter as a variable name and counts the records in that table. I'd like to retrieve the results of the dynamic statement (#toStartStr) into a variable (#toStart).
-- #tempTableName = SProc input parameter
DECLARE #toStartStr nvarchar(150);
DECLARE #toStart int;
SET #toStartStr = 'SELECT #toStart = COUNT(ID) FROM ' + #tempTableName;
EXEC(#toStartStr);
Right now, an error suggests that #toStart cannot be concatenated with the string SELECT, but this is the gist of what I want. Can anyone see what I'm doing wrong? Or suggest an alternative? FYI SQL 2008 R2. Thanks.
DECLARE #sql NVARCHAR(255);
DECLARE #toStart INT;
SET #sql = N'SELECT #toStart = COUNT(ID) FROM ' + QUOTENAME(#tempTableName);
EXEC sp_executesql #sql, N'#toStart INT OUTPUT', #toStart OUTPUT;
PRINT #toStart;
However there is a much easier and more efficient way to do this, if you're okay with ignoring current in-flight transactions (and you're using SQL Server 2005 or better - please specify the version when asking questions!).
DECLARE #toStart INT;
SELECT #toStart = SUM(rows)
FROM sys.partitions
WHERE [object_id] = OBJECT_ID(#tempTableName)
AND index_id IN (0,1);
PRINT #toStart;
Just for completeness, here is a solution for SQL Server 2000, which also doesn't require any special privileges (just connect and member of public):
DECLARE #toStart INT;
SELECT #toStart = [rows]
FROM sysindexes
WHERE id = OBJECT_ID(#tempTableName)
AND indid IN (0,1);
PRINT #toStart;
That said, if you're using a count to determine what the next ID might be, or something like that, I think you're approaching this the wrong way, since rows can be deleted and if it's an identity column values can be skipped due to rollbacks.
#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
it is very easy to use the following SQL to get value for a specific primary key: ID from a specific table: myTale:
DECLARE #v_maxID bigint;
SELECT #v_maxID = MAX(ID) FROM myTable;
What I need is a generic SQL codes to get the max value for a key from a table, where both key and table are specified as varchar(max) types as parameters:
DECLARE #v_maxID bigint;
-- SELECT #v_maxID = MAX(#p_ID) FROM #p_Table;
I comment out the SELECT since it is not working. I tried to build a SQL string and I can EXEC it, but I cannot get the max value back to my local variable(#v_maxID). Any suggestions?
DECLARE #max bigint, #sql nvarchar(max)
SET #sql = N'SELECT #max = MAX(' + #p_ID + ') FROM ' + #p_Table
EXEC sp_executesql
#query = #sql,
#params = N'#max bigint OUTPUT',
#max = #max OUTPUT
PRINT #max
Users are choosers, but I consider this an ugly idea (for being overgeneralized). And unoptimizable. Just write the SQL.
Correct me if I'm wrong, but don't you just want:
SELECT MAX(ID) FROM mytable
Just build the query at the app level, thus the query running would be just like the one above. Doing in on sql will certainly open you for sql injection, since you have to use exec(). Also in either case, be careful with user input.
As BC states, you have to use sp_executesql with an OUTPUT parameter.
How to specify output parameters when you use the sp_executesql stored procedure in SQL Server