SQL Server: Capturing Dynamic SQL Query Results in a Variable
Stored procedures often utilize dynamic SQL, building queries on the fly. The key challenge is retrieving the results of these dynamic queries within the procedure itself.
Consider this scenario:
DECLARE @sqlCommand nvarchar(1000) DECLARE @city varchar(75) SET @city = 'London' SET @sqlCommand = 'SELECT COUNT(*) FROM customers WHERE City = @city' EXECUTE sp_executesql @sqlCommand, N'@city nvarchar(75)', @city = @city
This code snippet dynamically generates a COUNT(*)
query, but doesn't capture the result. To address this, we need a modified approach:
DECLARE @sqlCommand NVARCHAR(1000) DECLARE @count INT DECLARE @city VARCHAR(75) SET @city = 'New York' SET @sqlCommand = 'SELECT @cnt=COUNT(*) FROM customers WHERE City = @city' EXECUTE sp_executesql @sqlCommand, N'@city nvarchar(75), @cnt int OUTPUT', @city = @city, @cnt = @count OUTPUT SELECT @count
Here's a detailed explanation:
-
Declare a Result Variable: We declare
@cnt
as anINT
to hold the query's output. -
Modify the Dynamic SQL: The
SELECT
statement is adjusted to assign theCOUNT(*)
result to@cnt
:SELECT @cnt=COUNT(*)
. -
Use
sp_executesql
with OUTPUT:sp_executesql
is used with theOUTPUT
parameter to specify that@cnt
will receive a value from the query. Note the parameter declaration@cnt int OUTPUT
. -
Retrieve the Result: After execution,
@cnt
contains the count.SELECT @count
displays the stored value.
This refined method efficiently captures dynamic SQL results into a variable, enabling further processing or return within the stored procedure.
The above is the detailed content of How to Capture Dynamic SQL Query Results into a Variable in SQL Server?. For more information, please follow other related articles on the PHP Chinese website!

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