I have a table that is the result of an INNER JOIN and then to that table I have to a apply a bunch of queries, so at the end the whole code in SQL is really big and in the future (and that's the main problem) I will have problems to understand what did I do.
So for this reason I am considering the possibility of creating views, so in each step I have a view created and I know what does each one of the queries.
So with that goal I started to use IF ELSE statements to create views if they dont' exist etc. but I'm stumbling with a lot of errors and problems.
First of all, this is the way I'm creating a view with the IF statement:
-- This portion of code is common in all the views
IF NOT EXISTS
(
SELECT 1
FROM sys.views
WHERE Name = 'NAME_OF_THE_VIEW'
)
BEGIN
EXEC('CREATE VIEW NAME_OF_THE_VIEW AS SELECT 1 as Val')
END
GO
ALTER VIEW NAME_OF_THE_VIEW
AS
-- Here I put the query of the view
SELECT *
FROM table_1
When I execute this code it works, but the SQL Server Management Studio underlines "NAME_OF_THE_VIEW" in the ALTER VIEW statement and when I hover the mouse it says: Invalid object name 'NAME_OF_THE_VIEW'. I don't understand why if there's a supposed error it still works.
The other problem is that when I introduce more code like the code above in order to create other views in the same script, the whole ALTER VIEW statement is underlined and when I hover this message appears; Incorrect syntax: 'ALTER VIEW' must be the only statement in the batch.
So the question is: hoy can I put everything in the same script, where I can create views to avoid doing a lot of subqueries, and without getting this errors? The SQL-Server version is 15.
So the question is: hoy can I put everything in the same script, where I can create views to avoid doing a lot of subqueries, and without getting this errors?
There's no need to check for existence of the view. Just CREATE OR ALTER VIEW
CREATE OR ALTER VIEW NAME_OF_THE_VIEW
AS
-- Here I put the query of the view
SELECT *
FROM table_1
GO
CREATE OR ALTER VIEW NAME_OF_THE_OTHER_VIEW
AS
-- Here I put the query of the view
SELECT *
FROM table_1
I understand that you cannot simply drop an SQL server schema, you must first of all drop all the objects contained therein. I found this stored proc that performs the task of dropping all objects and then the schema itself.
Is there really no simpler way to drop a schema? Ideally, I'd like to find a way to do this without using a stored proc.
Also, it seems like the stored proc will cause errors if the schema name provided does not exist. I would like it to simply do nothing instead. I guess this is simply a matter of putting this pseudocode at the top of the script
IF #SchemaName NOT EXISTS
QUIT
Can someone convert this into language that SQL Server will understand?
The following at the top of the script should help:
IF SCHEMA_ID(#SchemaName) IS NULL
RETURN
SCHEMA_ID returns the schema ID associated with a schema name, and RETURN exits unconditionally from a query or procedure.
You have to remove all objects in the schame before dropping it or migrate all objects to a new schema. There is no "wildcard" option for either
To exit a stored procedure before any further processing...
IF SCHEMA_ID(#SchemaName) IS NULL
RETURN
if exists(select * from sys.schemas where name = #SchemaName)
begin
-- Your work
end
You must drop all objects before dropping the schema.
To check if a schema exists:
IF NOT EXISTS (select SCHEMA_NAME from INFORMATION_SCHEMA.SCHEMATA WHERE CATALOG_NAME='YOUR DB NAME HERE' and SCHEMA_NAME=#SchemaName)
BEGIN
-- Do some processing...
return
END
I have three stored procedures Sp1, Sp2 and Sp3.
The first one (Sp1) will execute the second one (Sp2) and save returned data into #tempTB1 and the second one will execute the third one (Sp3) and save data into #tempTB2.
If I execute the Sp2 it will work and it will return me all my data from the Sp3, but the problem is in the Sp1, when I execute it it will display this error:
INSERT EXEC statement cannot be nested
I tried to change the place of execute Sp2 and it display me another error:
Cannot use the ROLLBACK statement
within an INSERT-EXEC statement.
This is a common issue when attempting to 'bubble' up data from a chain of stored procedures. A restriction in SQL Server is you can only have one INSERT-EXEC active at a time. I recommend looking at How to Share Data Between Stored Procedures which is a very thorough article on patterns to work around this type of problem.
For example a work around could be to turn Sp3 into a Table-valued function.
This is the only "simple" way to do this in SQL Server without some giant convoluted created function or executed sql string call, both of which are terrible solutions:
create a temp table
openrowset your stored procedure data into it
EXAMPLE:
INSERT INTO #YOUR_TEMP_TABLE
SELECT * FROM OPENROWSET ('SQLOLEDB','Server=(local);TRUSTED_CONNECTION=YES;','set fmtonly off EXEC [ServerName].dbo.[StoredProcedureName] 1,2,3')
Note: You MUST use 'set fmtonly off', AND you CANNOT add dynamic sql to this either inside the openrowset call, either for the string containing your stored procedure parameters or for the table name. Thats why you have to use a temp table rather than table variables, which would have been better, as it out performs temp table in most cases.
OK, encouraged by jimhark here is an example of the old single hash table approach: -
CREATE PROCEDURE SP3 as
BEGIN
SELECT 1, 'Data1'
UNION ALL
SELECT 2, 'Data2'
END
go
CREATE PROCEDURE SP2 as
BEGIN
if exists (select * from tempdb.dbo.sysobjects o where o.xtype in ('U') and o.id = object_id(N'tempdb..#tmp1'))
INSERT INTO #tmp1
EXEC SP3
else
EXEC SP3
END
go
CREATE PROCEDURE SP1 as
BEGIN
EXEC SP2
END
GO
/*
--I want some data back from SP3
-- Just run the SP1
EXEC SP1
*/
/*
--I want some data back from SP3 into a table to do something useful
--Try run this - get an error - can't nest Execs
if exists (select * from tempdb.dbo.sysobjects o where o.xtype in ('U') and o.id = object_id(N'tempdb..#tmp1'))
DROP TABLE #tmp1
CREATE TABLE #tmp1 (ID INT, Data VARCHAR(20))
INSERT INTO #tmp1
EXEC SP1
*/
/*
--I want some data back from SP3 into a table to do something useful
--However, if we run this single hash temp table it is in scope anyway so
--no need for the exec insert
if exists (select * from tempdb.dbo.sysobjects o where o.xtype in ('U') and o.id = object_id(N'tempdb..#tmp1'))
DROP TABLE #tmp1
CREATE TABLE #tmp1 (ID INT, Data VARCHAR(20))
EXEC SP1
SELECT * FROM #tmp1
*/
My work around for this problem has always been to use the principle that single hash temp tables are in scope to any called procs. So, I have an option switch in the proc parameters (default set to off). If this is switched on, the called proc will insert the results into the temp table created in the calling proc. I think in the past I have taken it a step further and put some code in the called proc to check if the single hash table exists in scope, if it does then insert the code, otherwise return the result set. Seems to work well - best way of passing large data sets between procs.
This trick works for me.
You don't have this problem on remote server, because on remote server, the last insert command waits for the result of previous command to execute. It's not the case on same server.
Profit that situation for a workaround.
If you have the right permission to create a Linked Server, do it.
Create the same server as linked server.
in SSMS, log into your server
go to "Server Object
Right Click on "Linked Servers", then "New Linked Server"
on the dialog, give any name of your linked server : eg: THISSERVER
server type is "Other data source"
Provider : Microsoft OLE DB Provider for SQL server
Data source: your IP, it can be also just a dot (.), because it's localhost
Go to the tab "Security" and choose the 3rd one "Be made using the login's current security context"
You can edit the server options (3rd tab) if you want
Press OK, your linked server is created
now your Sql command in the SP1 is
insert into #myTempTable
exec THISSERVER.MY_DATABASE_NAME.MY_SCHEMA.SP2
Believe me, it works even you have dynamic insert in SP2
I found a work around is to convert one of the prods into a table valued function. I realize that is not always possible, and introduces its own limitations. However, I have been able to always find at least one of the procedures a good candidate for this. I like this solution, because it doesn't introduce any "hacks" to the solution.
I encountered this issue when trying to import the results of a Stored Proc into a temp table, and that Stored Proc inserted into a temp table as part of its own operation. The issue being that SQL Server does not allow the same process to write to two different temp tables at the same time.
The accepted OPENROWSET answer works fine, but I needed to avoid using any Dynamic SQL or an external OLE provider in my process, so I went a different route.
One easy workaround I found was to change the temporary table in my stored procedure to a table variable. It works exactly the same as it did with a temp table, but no longer conflicts with my other temp table insert.
Just to head off the comment I know that a few of you are about to write, warning me off Table Variables as performance killers... All I can say to you is that in 2020 it pays dividends not to be afraid of Table Variables. If this was 2008 and my Database was hosted on a server with 16GB RAM and running off 5400RPM HDDs, I might agree with you. But it's 2020 and I have an SSD array as my primary storage and hundreds of gigs of RAM. I could load my entire company's database to a table variable and still have plenty of RAM to spare.
Table Variables are back on the menu!
I recommend to read this entire article. Below is the most relevant section of that article that addresses your question:
Rollback and Error Handling is Difficult
In my articles on Error and Transaction Handling in SQL Server, I suggest that you should always have an error handler like
BEGIN CATCH
IF ##trancount > 0 ROLLBACK TRANSACTION
EXEC error_handler_sp
RETURN 55555
END CATCH
The idea is that even if you do not start a transaction in the procedure, you should always include a ROLLBACK, because if you were not able to fulfil your contract, the transaction is not valid.
Unfortunately, this does not work well with INSERT-EXEC. If the called procedure executes a ROLLBACK statement, this happens:
Msg 3915, Level 16, State 0, Procedure SalesByStore, Line 9 Cannot use the ROLLBACK statement within an INSERT-EXEC statement.
The execution of the stored procedure is aborted. If there is no CATCH handler anywhere, the entire batch is aborted, and the transaction is rolled back. If the INSERT-EXEC is inside TRY-CATCH, that CATCH handler will fire, but the transaction is doomed, that is, you must roll it back. The net effect is that the rollback is achieved as requested, but the original error message that triggered the rollback is lost. That may seem like a small thing, but it makes troubleshooting much more difficult, because when you see this error, all you know is that something went wrong, but you don't know what.
I had the same issue and concern over duplicate code in two or more sprocs. I ended up adding an additional attribute for "mode". This allowed common code to exist inside one sproc and the mode directed flow and result set of the sproc.
what about just store the output to the static table ? Like
-- SubProcedure: subProcedureName
---------------------------------
-- Save the value
DELETE lastValue_subProcedureName
INSERT INTO lastValue_subProcedureName (Value)
SELECT #Value
-- Return the value
SELECT #Value
-- Procedure
--------------------------------------------
-- get last value of subProcedureName
SELECT Value FROM lastValue_subProcedureName
its not ideal, but its so simple and you don't need to rewrite everything.
UPDATE:
the previous solution does not work well with parallel queries (async and multiuser accessing) therefore now Iam using temp tables
-- A local temporary table created in a stored procedure is dropped automatically when the stored procedure is finished.
-- The table can be referenced by any nested stored procedures executed by the stored procedure that created the table.
-- The table cannot be referenced by the process that called the stored procedure that created the table.
IF OBJECT_ID('tempdb..#lastValue_spGetData') IS NULL
CREATE TABLE #lastValue_spGetData (Value INT)
-- trigger stored procedure with special silent parameter
EXEC dbo.spGetData 1 --silent mode parameter
nested spGetData stored procedure content
-- Save the output if temporary table exists.
IF OBJECT_ID('tempdb..#lastValue_spGetData') IS NOT NULL
BEGIN
DELETE #lastValue_spGetData
INSERT INTO #lastValue_spGetData(Value)
SELECT Col1 FROM dbo.Table1
END
-- stored procedure return
IF #silentMode = 0
SELECT Col1 FROM dbo.Table1
Declare an output cursor variable to the inner sp :
#c CURSOR VARYING OUTPUT
Then declare a cursor c to the select you want to return.
Then open the cursor.
Then set the reference:
DECLARE c CURSOR LOCAL FAST_FORWARD READ_ONLY FOR
SELECT ...
OPEN c
SET #c = c
DO NOT close or reallocate.
Now call the inner sp from the outer one supplying a cursor parameter like:
exec sp_abc a,b,c,, #cOUT OUTPUT
Once the inner sp executes, your #cOUT is ready to fetch. Loop and then close and deallocate.
If you are able to use other associated technologies such as C#, I suggest using the built in SQL command with Transaction parameter.
var sqlCommand = new SqlCommand(commandText, null, transaction);
I've created a simple Console App that demonstrates this ability which can be found here:
https://github.com/hecked12/SQL-Transaction-Using-C-Sharp
In short, C# allows you to overcome this limitation where you can inspect the output of each stored procedure and use that output however you like, for example you can feed it to another stored procedure. If the output is ok, you can commit the transaction, otherwise, you can revert the changes using rollback.
On SQL Server 2008 R2, I had a mismatch in table columns that caused the Rollback error. It went away when I fixed my sqlcmd table variable populated by the insert-exec statement to match that returned by the stored proc. It was missing org_code. In a windows cmd file, it loads result of stored procedure and selects it.
set SQLTXT= declare #resets as table (org_id nvarchar(9), org_code char(4), ^
tin(char9), old_strt_dt char(10), strt_dt char(10)); ^
insert #resets exec rsp_reset; ^
select * from #resets;
sqlcmd -U user -P pass -d database -S server -Q "%SQLTXT%" -o "OrgReport.txt"
I am curious whether I can drop multiple procedures by simple using "%"?
Like:
DROP constantName%
When I use DROP in the Management studio, it looks like that:
/****** Object: StoredProcedure [dbo].[x] Script Date: 02/02/2010 09:36:25 ******/
IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[x]') AND type in (N'P', N'PC'))
DROP PROCEDURE [dbo].[x]
Why it is checking the object ID when I am dropping this particular object?
The OBJECT_ID returns the database object identification number of a schema-scoped object. In your code it is checking it inside an IF EXISTS, so that it will only DROP the stored proc if is present in the database.
You could just have DROP PROCEDURE proc_name, but you could end up getting an error if the procedure does not exist. Its just good practise to check before you remove.
Tables, View, Stored Procs etc all have an OBJECT_ID as a key identifier.
I do not believe you can drop mutiple stored procedures using a LIKE. (Though i;m not 100% certain on that)
I think SQL was designed with this limitation, the drop procedure command needs a string constant. You can't pass a variable as an argument either, it just gives a 'incorrect syntax' error when you do.
Also the OBJECT_ID function only returns a valid id of objects the user owns, or has permission to. So OBJECT_ID is used because it performs the security validation.
Deleting with just "WHERE name = 'object_name'" could also work, but only if the user has permission for that object.
I am afraid you cant use the like syntax in DROP, below the simple one liner to drop multiple procedures.
DROP PROCEDURE testest,testest1
And for your 2nd question. There are scenarious we can create Storedprocedure that can be accessible only to the particular role.
create proc dbo.testest
as
begin
select 1
end
query sys.objects with the role value
select * from sys.objects where name ='dbo.testest'
it returns null
select * from sys.objects where name ='testest'
now it works
sys.objects catalog view stores the information without the role names (only just names). But using OBJECT_ID, we can retrieve the role specific info
select OBJECT_ID('dbo.testest') //works
select OBJECT_ID('testest') //works
hope you can understand now.
I have a lot of code I am trying to run where I'm querying the sysobjects table to check if an object exists before I drop it and create it again.
Issue being, sometimes if I go:
if not exists (select name from sysobjects o where o.name = 'my_table' and o.type = 'U')
CREATE TABLE my_table (..)
go
it works, no worries. However, when I came back to run it again, I get this lovely error:
SQL Server Error on (myserver) Error:2714 at Line:10 Message:There is already an object named 'my_table' in the database.
Thanks for that, SQL Programmer. I actually asked for you not to create this table if it already exists. -_-
Any ideas?
the logic to what you are doing doesn't seem quite right. based on your statement:
"I am trying to run where I'm querying the sysobjects table to check if an object exists before I drop it and create it again"
you should simply do a delete followed by a create. This way is usually better because it ensures that the table will be updated. if the table existed and you had changes, you are probably not getting what you want.
The immediate issue you are running into is an assumed db ownership that was not consistent between runs.
based on your clarification below - here is what you can do:
IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[XXXX]') AND type in (N'U'))
DROP TABLE [dbo].[XXXX]
GO
CREATE TABLE [dbo].[XXXX(...
GO
you can run this over and over again...
The sybase parsers object validation pass is global and not based on conditional evaluation. Even though your code can not execute CREATE TABLE the statement is still checked for syntax and applicability which fails when the system sees that the table already exists.
The only way around this that I know of is to put your create statements inside of an EXEC() which would be evaluated only if the section was executed.
yes, the entire batch of SQL is normalized and compiled so as to create an "execution plan" for the entire batch. During normalization, the "possible" "create table" statement is a problem if it already exists at compile time.
My solution: rename -
if exists (select 1 from ....)
begin
drop table xyz
create table xyz_zzzz ( ... )
exec sp_rename 'xyz_zzzz','xyz'
end