I am using SQL Server 2017 and I would like to create a stored procedure with a single table name as an input variable. All I want the procedure to do is update that table in a variety of ways. This project will be done twice a year, and the columns will always be the same, so I would like to try this as a stored procedure, so I do not have to highlight several lines of code and executing each time.
Is there a simple way to pass a table name through a stored procedure which updates the table (adding columns, calculating columns, replacing nulls in columns etc). In a basic example, one task would be just replaces nulls with 0s in a column. I am not sure how to set this up though. DO I have to declare every column in the table too?
CREATE PROCEDURE updteleform
#tablename TABLE
AS
BEGIN
UPDATE #tablename
SET Recog = 0
WHERE Recog IS NULL
END
GO
I'm assuming you want to update a physical table. SQL Server table variables don't work that way, rather they are a way to pass a transient result set to a stored procedure. There is no persistence if your stored procedure does not do so.
If you are looking to update the same table, then just write the procedure to work on that table.
If you are looking to update multiple tables using the same script then you should change your procedure to accept a string parameter that would be the name of the table you want it to work on and then use dynamic SQL in your stored procedure.
Something like
CREATE PROCEDURE updteleform #tablename sysname
AS
BEGIN
DECLARE #sql NVARCHAR(MAX);
SET #sql = N'
update ' + QUOTENAME(#tablename) + '
set Recog= 0
where Recog is null;';
EXEC sp_executesql #sql;
END
GO
And then call it with something like:
EXEC updteleform #tablename = 'table1';
EXEC updteleform #tablename = 'table2';
EXEC updteleform #tablename = 'table3';
...
Related
I have a stored procedure, usp_region and it has a select statement with 50 columns as the result set. This procedure is called by multiple other stored procedures in our application.
Most of the stored procedure pass a parameter to this procedure and display the result set that it returns. I have one stored procedure, usp_calculatedDisplay, that gets the columns from this stored procedure and inserts the values into a temp table and does some more calculations on the columns.
Here's a part of the code in usp_calculatedDisplay.
Begin Procedure
/* some sql statements */
Declare #tmptable
(
-- all the 50 columns that are returned from the usp_region procedure
)
Insert Into #tmptable
exec usp_region #regionId = #id
Select t.*, /* a few calculated columns here */
From #tmptable t
End of procedure
Every time I add a column to the usp_region procedure, I'll also have to make sure I have to add it to this procedure. Otherwise it breaks. It has become difficult to maintain it since it is highly possible for someone to miss adding a column to the usp_calculatedDisplay procedure when the column is added to the usp_region.
In order to overcome this problem, I decided to do this:
Select *
Into #tmptable
From OPENROWSET('SQLNCLI',
'Server=localhost;Trusted_Connection=yes;',
'EXEC [dbo].[usp_region]')
The problem is 'Ad Hoc Distributed Queries' component is turned off. So I can't use this approach to overcome this issue. I was wondering if there are any other ways of overcoming this problem. I would really appreciate any help. Thank you!
Every time I add a column to the usp_region procedure
SQL Server is a structured database and it does not meant to solve such cases that you need to change your structure every day.
If you add/remove columns so often then you probably did not choose the right type of database, and you better re-design your system.
It has become difficult to maintain it since it is highly possible for someone to miss adding a column to the usp_calculatedDisplay procedure when the column is added to the usp_region.
There are two simple solutions for this (1) using DDL Triggers - very bad idea but simple to implement and working. (2) Using my trick to select from stored procedure
Option 1: using DDL trigger
You can automate the entire procedure and ALTER the stored procedure usp_calculatedDisplay every time that the stored procedure usp_region is changed
https://learn.microsoft.com/en-us/sql/relational-databases/triggers/ddl-triggers
The basic approach is
CREATE OR ALTER TRIGGER NotGoodSolutionTrig ON DATABASE FOR ALTER_PROCEDURE AS BEGIN
DECLARE #var_xml XML = EVENTDATA();
IF(
#var_xml.value('(EVENT_INSTANCE/DatabaseName)[1]', 'sysname') = 'tempdb'
and
#var_xml.value('(EVENT_INSTANCE/SchemaName)[1]', 'sysname') = 'dbo'
and
#var_xml.value('(EVENT_INSTANCE/ObjectName)[1]', 'sysname') = 'usp_region'
)
BEGIN
-- Here you can parse the text of the stored procedure
-- and execute ALTER on the first SP
-- To make it simpler, you can design the procedure usp_region so the columns names will be in specific row or between to comment which will help us to find it
-- The code of the Stored Procedure which you need to parse is in the value of:
-- #var_xml.value('(EVENT_INSTANCE/TSQLCommand/CommandText)[1]', 'NVARCHAR(MAX)'))
-- For example we can print it
DECLARE #SP_Code NVARCHAR(MAX)
SET #SP_Code = CONVERT(NVARCHAR(MAX), #var_xml.value('(EVENT_INSTANCE/TSQLCommand/CommandText)[1]', 'NVARCHAR(MAX)'))
PRINT #SP_Code
-- In your case, you need to execute ALTER on the usp_calculatedDisplay procedure using the text from usp_region
END
END
Option 2: trick to select from stored procedure using sys.dm_exec_describe_first_result_set
This is simple and direct way to get what you need.
CREATE OR ALTER PROCEDURE usp_calculatedDisplay AS
-- Option: using simple table, so it will exists outsie the scope of the dynamic query
DROP TABLE IF EXISTS MyTable;
DECLARE #sqlCommand NVARCHAR(MAX)
select #sqlCommand = 'CREATE TABLE MyTable(' + STRING_AGG ([name] + ' ' + system_type_name, ',') + ');'
from sys.dm_exec_describe_first_result_set (N'EXEC usp_region', null,0)
PRINT #sqlCommand
EXECUTE sp_executesql #sqlCommand
INSERT MyTable EXECUTE usp_region;
SELECT * FROM MyTable;
GO
Note!!! Both solutions are not recommended in production. My advice is to avoid such needs by redesign your system. If you need to re-write 20 SP so do it and don't be lazy! Your goal should be what best for the database usage.
We have a process that updates certain tables based on a parameter passed in, specifically a certain state. I know organizationally this problem would be eliminated by using a single table for this data, but that is not an option -- this isn't my database.
To update these tables, we run a stored procedure. The only issue is that there was a stored procedure for each state, and this made code updates horrible. In order to minimize the amount of code needing to be maintained, we wanted to move towards a single stored procedure that takes in a state parameter, and updates the correct tables. We wanted this without 50 If statements, so the only way I could think to do this was to save the SQL code as text, and then execute the string. IE:
SET #SSQL = 'UPDATE TBL_' + #STATE +' SET BLAH = FOO'
EXEC #SSQL;
I was wondering if there was a way to do this without using strings to update the correct tables based on that parameter. These stored procedures are thousands of lines long.
Thanks all!
Instead save entire script as SQL text and execute it, just update the required table using like code below as where you need and rest continue as it is
EXEC('UPDATE TBL_' + #STATE +' SET BLAH = FOO')
You could, indeed, use dynamic SQL (the exec function) - but with long, complex stored procedures, that can indeed be horrible.
When faced with a similar problem many years ago, we created the stored procedures by running a sort of "mail-merge". We'd write the procedure to work against a single table, then replace the table names with variables and used a PHP script to output a stored procedure for each table by storing the table names in a CSV file.
You could replicate that in any scripting language of your choice - it took about a day to get this to work. It had the added benefit of allowing us to easily store the stored proc templates in source code control.
You can safely use sp_executesql which is fairly more appropriate than a simple EXEC command. To do so, even with input and output parameters :
DECLARE #sql nvarchar(4000),
#tablename nvarchar(4000) = 'YOUR_TABLE_NAME',
#params nvarchar(4000),
#count int
SELECT #sql =
N' UPDATE ' + #tablename +
N' SET Bar = #Foo;' +
N' SELECT #count = ##rowcount'
SELECT #params =
N'#Foo int, ' +
N'#count int OUTPUT'
EXEC sp_executesql #sql, #params, 2, #count OUTPUT
SELECT #count [Row(s) updated]
I encourage you reading the related part of the article mentionned here.
I'm writing a stored procedure. I have a string which contains an sql query. For example:
DECLARE #sql nvarchar(max)
SET #sql = (N'SELECT pkOrderID FROM Orders')
(Just to note: this isn't what the select statement looks like. This is just an example of what I mean) I then want to execute the string and put the result in a temporary table E.g. #tempTable. I know EXEC(#sql) exists but not sure if it will do me any good in this situation. The other twist is that I do not know the names of all the columns in the returned #sql so the temp table #tempTable needs to be created dyanmically based off the return from #sql. Thanks for any help.
I think you could use SELECT INTO to do what you want but it would mean updating your string:
DECLARE #sql nvarchar(max)
SET #sql = (N'SELECT frompkOrderID INTO #tmporders FROM Orders')
then you should be able to run EXEC #sql to create the table
more information about SELECT INTO here : http://msdn.microsoft.com/en-au/library/ms188029.aspx
There is no simple way to do this. The problem with #JanR's solution is that the #tmporders table will be out of scope to the script that calls your stored procedure (ie It will produce an error like "Invalid object name '#rtmporders'"
One alternative is to use a global temp table (eg ##tmporders).
So your SP might look like this:
CREATE PROCEDURE TestSP
AS
BEGIN
SELECT pkOrderID INTO ##tmporders FROM Orders
END
GO
And the calling script might be like:
EXEC TestSP
SELECT * FROM ##temporders
My SQL is quite limited and I have a number of databases within my server, I'm wondering whether its possible to write an SQL Query to loop through a listing of table names and then alter a particular table within the database name to modify a table in that database ?
Im simply wishing to add a new column to a table called site_settings.
Does MSSQL have this ability ?
You can use the script below. It returns an alter statement for each user table (you need to change your new column type as you didn't specify it) and then executes the query.
declare #sql nvarchar(max) = ''
select #sql = #sql + 'alter table ' + name + ' add site_settings int null;'
from sys.tables where type ='U'
exec sp_executesql #sql
I am working with sql server 2008
I have a database table that has a column containing a stored procedure name.
I want to query the database table which returns a list of the stored procedure names, and execute them.
The stored procedures are similar all having a select statment. The data returned in this select statement I want to insert in to a data base table.
Pseudo code looks like this:
INSERT INTO MyTable
EXECUTE sp_executesql SELECT StoredProcedureName FROM Table
Anyone able to assist me with correct sql for achieveing the above?
sp_executesql accepts a unicode string not a tsql statement. So you would need to execute your procedure(s) like this:
execute sp_executesql 'execute ' + #storedprocedurename
which will execute a single procedure.
You will need to write some iterative process to populate the #storedprocedurename variable from your source table.
This is pretty much same as #Coltech answer just with cursor.
DECLARE #spname VARCHAR(200)
DECLARE #sql VARCHAR(1000)
DECLARE your_cursor CURSOR FOR
SELECT spname
FROM yourTable;
OPEN your_cursor;
FETCH NEXT FROM your_cursor
INTO #spname;
WHILE ##FETCH_STATUS = 0
BEGIN
SET #sql = 'EXEC ' + #spname
execute sp_executesql #sql
FETCH NEXT FROM your_cursor
INTO #spname;
END
CLOSE your_cursor;