Execute sp_executesql, Table Variabe not Declared - sql

I am Using SQL server 2012 and i want to select random columns from my table by applying where condition in this query:
EXECUTE sp_executesql
N'SELECT *
FROM #table
WHERE #Col = #Value',
N'#Value nvarchar(44),#table nvarchar(55),#Col nvarchar(30)',
#Value = 'Cus_1',#Col='CustId',#table='SaleOrder';
But when I execute it, it shows error
Must declare the table variable "#table"
I also tried it to declare by this: #table table(Id nvarchar(30)), but thin it shows again an error on table type...
Please help

This is what you are trying to run:
EXECUTE sp_executesql
N'SELECT * FROM #table WHERE #Col = #Value',
N'#Value nvarchar(44), #table nvarchar(55), #Col nvarchar(30)',
#Value = 'Cus_1', #Col='CustId', #table='SaleOrder';
Alas. You cannot substitute in a table name or column name using parameter substitution. So, SQL Server is looking for a table variable called #table. You can fix this by putting the values directly into the string:
declare #Col = 'CustId', #table = 'SaleOrder';
declare #sql nvarchar(max) = N'SELECT * FROM ' + #table + ' WHERE ' + #Col + ' = #Value';
EXECUTE sp_executesql #sql,
N'#Value nvarchar(44)',
#Value = 'Cus_1';
Unfortunately, I cannot find a good reference in the documentation that explains what is happening. When a statement is compiled, it is allowed to have parameters. However, the parameters are for values in the statement, not for column, table, database, or UDF names or for keywords. The statement itself is compiled, with place holders for the parameters, and in order to be compiled, the SQL engine needs to resolve all object names.

Related

Setting SQL Variable via Dynamic SQL

I know I am overthinking this, but I've been banging against this for too long so I'm reaching out for help.
This is the statement I'm trying to run: SELECT #cntMax = MAX(id) FROM [Raw_Item-FieldReport]
BUT, the table name is a variable #reportTable
This doesn't work:
SET #sql = 'SELECT #cntMax = MAX(id) FROM #reportTable'
EXEC sp_executesql #sql
I even tried having the actual table name in the SET #sql and that doesn't work either.
I didn't think it would be this difficult, please tell me I'm missing something easy/obvious.
Here's the full bit of code for those who want it:
DECLARE
#inTable nvarchar(255) = 'Raw_Item',
#reportTable nvarchar(255),
#fieldName nvarchar(255),
#cnt int,
#cntMax int,
#sql nvarchar(max)
SET #reportTable = #inTable + '-FieldReport'
SET #cnt = 1
SELECT #cntMax = MAX(id) FROM [Raw_Item-FieldReport]
PRINT #cntMax
SET #cntMax = 0
SET #sql = 'SELECT #cntMax = MAX(id) FROM [Raw_Item-FieldReport]'
EXEC sp_executesql #sql
PRINT #cntMax
SQL Server 12.0.2008.8 (on Azure)
You need to use an output parameter, otherwise SQL Server has no idea how to connect #cntMax in the dynamic SQL to #cntMax not in the dynamic SQL, since they are different scopes. And to protect yourself from SQL injection (some tips here and here), always check that your object exists, and use QUOTENAME() as opposed to manually adding square brackets (and you should always use QUOTENAME() when building object names from user input or variables, even when they don't have bad characters like dashes):
DECLARE #sql nvarchar(max),
#inTable nvarchar(255) = N'Raw_Item',
#reportTable nvarchar(255);
SET #reportTable = N'dbo.' + QUOTENAME(#inTable + '-FieldReport');
IF OBJECT_ID(#reportTable) IS NOT NULL
BEGIN
SET #sql = N'SELECT #cntMax = MAX(id) FROM ' + #reportTable + N';';
EXEC sys.sp_executesql #sql,
N'#cntMax int output',
#cntMax = #cntMax OUTPUT;
PRINT #cntMax;
END
ELSE
BEGIN
PRINT 'Nice try, h#xx0rs!';
END
Always use schema reference (dbo), always use statement terminators, and please try to avoid naming things with invalid identifier characters like dash (-). And one additional tip: always use N prefix on N'nvarchar string literals'.

Issues with equal sign when assigning statement to # variable for EXEC sp_executesql

Hello: I am trying to encapsulate the following Insert and select statement into a variable for SQL to run.
The issue occurs when the equals sign is included for evaluation (or right around there)
The CustomPollerAssignmentID Column had to be cast since it natively a PK and a uniqueidentifier (see image)
What must be done to have the statement evaluate properly when passes to the sp_executesql?
I receive a syntax error as illustrated below
declare
#date datetime,
#query nvarchar(Max)
set #date = getdate()-4
set #query = --'Insert into [SolarWindsOrion].[dbo].[BWC_VPN_Hourly_Long_Store]
'SELECT * FROM [SolarWindsOrion].[dbo].[CustomPollerStatistics_Hourly]
where Cast(CustomPollerAssignmentID as nvarchar(max)) = 63FEB60-4516-4C1A-9A11-DB30ACA44301'
EXEC sp_executesql #query
UPDATE-->
I tried adding the single quotes.
While the statement does execute.. no results are returned. See Image below
you need to put it in quote like this '63FEB60-4516-4C1A-9A11-DB30ACA44301' , so your adhoc query would look like this :
declare
#date datetime,
#query nvarchar(Max)
set #date = getdate()-4
set #query = --'Insert into [SolarWindsOrion].[dbo].[BWC_VPN_Hourly_Long_Store]
'SELECT * FROM [SolarWindsOrion].[dbo].[CustomPollerStatistics_Hourly]
where Cast(CustomPollerAssignmentID as nvarchar(max)) = ''63FEB60-4516-4C1A-9A11-DB30ACA44301'''
EXEC sp_executesql #query

How can I create a dynamic Select statement within a SQL Select statement?

I have a SELECT statement that can produce a list of values:
DECLARE #ValueList varchar(Max);
SELECT #ValueList = COALESCE(#ValueList + ',', '') + CAST(Val AS varchar(max))
FROM
(SELECT TOP (100) PERCENT tblSampleTable.SomeIDNumber AS Val
FROM tblSampleTable) AS ValuesThisYear
PRINT #ValList
This returns a list with values something like
val1,val2,val4,val9,
etc., ehich I can then feed into a stored procedure, or manage some other way.
Now I want to have the query that gets assessed for the list of values to be dynamic, maybe passed in or from another stored procedure, similar to this:
DECLARE #ValueList varchar(Max);
DECLARE #TSQL varchar(Max);
SET #TSQL = {stored proc to get base query}
SELECT #ValueList = COALESCE(#ValueList + ',', '') + CAST(Val AS varchar(max))
FROM
(#TSQL) AS ValuesThisYear
PRINT #ValList
I know that's the wrong syntax for including #TSQL, and that's what I'm trying to find out. I've viewed a number of threads and tried a number of methods, but am still not able to incorporate this dynamic part.
The tricky part seems to be the making of the list (the COALESCE and CAST statements), where I incorporate #ValList as part of the returned string.
Any help would be appreciated!
Dynamic SQL is usually about
Creating a variable that contains the exact SQL you want to run
Then using EXEC (#SQLvariable) to run that code
For example (not for production yet!) I've added a new variable #CustomSQL
DECLARE #ValueList varchar(Max);
DECLARE #TSQL varchar(Max);
DECLARE #CustomSQL varchar(Max);
SET #TSQL = {stored proc to get base query}
SET #CustomSQL =
'SELECT COALESCE(#ValueList + '','', '''') + CAST(Val AS varchar(max))
FROM (
' + #TSQL + '
) As ValuesThisYear;'
PRINT #CustomSQL
EXEC (#CustomSQL)
Notice that adding text/strings (e.g., the #TSQL variable) have to be entered as exact strings rather than their variable names. Also note apostrophes - you need to use '' every time you wish to refer to a '.
I also removed the variable name from the SELECT #ValueList = ... because the dynamic SQL cannot actually reference the variables - it has its own scope (?cannot remember the correct word) and doesn't have access to the variables. Solutions to this include
Using a temporary table e.g., #temp which can be referenced
Using the OUTPUT clause
Personally, I would approach it a different way - use the T-Sql provided to put data into a temporary table. Then use the temporary table in the other statement e.g.,
DECLARE #ValueList varchar(Max);
DECLARE #TSQL varchar(Max);
SET #TSQL = {stored proc to get base query}
DECLARE #CustomSQL varchar(Max)
CREATE TABLE #temp (Val varchar(1000))
SET #CustomSQL = 'INSERT INTO #temp (Val) ' + #TSQL
EXEC (#CustomSQL)
SELECT #ValueList = COALESCE(#ValueList + ',', '') + CAST(Val AS varchar(max))
FROM #temp As ValuesThisYear;
PRINT #ValList
I almost never get my dynamic SQL correct first try. Suggestions
Keep it as simple as possible
Before having a version that runs (e.g., EXEC (#CustomSQL)), comment the EXEC out and PRINT it instead.
Here are some examples from previous posts I've done recently
Query for R Machine Learning Services - Filtering Categories in Where Clause
Bottom of Dynamic columns depend on previous dynamic columns - TSQL

Scalar variable must be declared in SQL variable

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)

Creating SQL table using dynamic variable name

I want to create backup SQL tables using variable names.
something along the lines of
DECLARE #SQLTable Varchar(20)
SET #SQLTable = 'SomeTableName' + ' ' + '20100526'
SELECT * INTO quotename(#SQLTable)
FROM SomeTableName
but i'm getting
Incorrect syntax near '#SQLTable'.
It's just part of a small script for maintence so i don't have to worry about injections.
DECLARE #MyTableName sysname;
DECLARE #DynamicSQL nvarchar(max);
SET #MyTableName = 'FooTable';
SET #DynamicSQL = N'SELECT * INTO ' + QUOTENAME(#MyTableName) + ' FROM BarTable';
EXEC sp_executesql #DynamicSQL;
Unfortunately, you can't use bind variables for table names, column names, etc. IN this case you must generate dynamic SQL and use exec.
DECLARE #Script NVARCHAR(MAX);
SET #Script = N'SELECT * INTO SomeTableName_' + N'20100526' + N' FROM SomeTableName';
EXEC sp_executesql #Script
I've left the date separate as I assume you want to calculate it for every run.
You should look into using synonyms:
-- Create a synonym for the Product table in AdventureWorks2008R2.
CREATE SYNONYM MyProduct
FOR AdventureWorks2008R2.Production.Product;
GO
-- Query the Product table by using the synonym.
USE tempdb;
GO
SELECT ProductID, Name
FROM MyProduct
WHERE ProductID < 5;
GO
http://msdn.microsoft.com/en-us/library/ms177544.aspx
DECLARE #MyTableName nvarchar(20);
DECLARE #DynamicSQL nvarchar(1000);
SET #MyTableName = "FooTable";
SET #DynamicSQL = N'SELECT * INTO ' + #MyTableName + ' FROM BarTable';
exec #DynamicSQL;
this query is correct but just use single quote at the ("FooTable")='FooTable'