Can I recreate a temp table after dropping it? - sql-server

Given:
code inside a stored proc:
select bleh
into #tblTemp
from FunctionThatReturnsTable('some','params')
-- do some stuff
drop table #tblTemp
-- Error on this command:
-- 'There is already an object named '#tblTemp' in the database.'
select bleh
into #tblTemp
from FunctionThatReturnsTable('some','other params')
Problem:
I can't recreate this temp table. My work around is to use #tmpTable1, #tmpTable2, #tempTable3 etc. Is there a way I can get around this? It would be nice just use one temp table each time.
If not, what is the reason for this?

As my comment reflected, I'm going to suggest that the answer is that you use a different #temp table name for each object that you create. It's kind of like saying to the doctor, "it hurts when I do this." His likely response is going to be, "stop doing that!"
The reason this is a problem is that SQL Server's parser attempts to parse the entire batch in one shot. It can clearly see that you are trying to create the same #temp table multiple times, but ignores the DROP command in between (I can't tell you exactly why that is, as I don't have access to the source code). This is the same reason you can't do this:
IF (1=1)
CREATE TABLE #foo(i INT);
ELSE
CREATE TABLE #foo(i VARCHAR(32));
The parser sees the two identical names, but can't really follow the IF/ELSE logic.
In addition to avoiding the problems multiple identically-named #temp tables causes the parser, another benefit to using unique names is that they can be re-used if you don't explicitly drop them. This will lighten the load on tempdb in terms of metadata / locking.

I ran into this problem with deleting+inserting column. The problem is probably with the parser, that it 'recognizes' the table on first create, and cannot see it was deleted.
I'd suggest using exec sp_executesql 'create table'

This is a feature by design and is clarified by Microsoft against Microsoft Connect Bug ID 666430
Please see a case study on the same at
temporary-table-could-not-be-re-created

Related

What is "dummy" in CREATE PROCEDURE statement

I'm doing investigation of code repo and find one thing that make me confused. SQL Server stored procedures are contained in a repo as a set of queries with following structure:
IF OBJECT_ID(N'[dbo].[sp_ProcTitle]', N'P') IS NULL
BEGIN
EXEC dbo.sp_executeSQL N'CREATE PROCEDURE [dbo].[sp_ProcTitle] AS dummy:;';
END
ALTER PROCEDURE dbo.sp_ProcTitle
#ParamOne int,
#ParamTwo date,
#ParamThree int
AS
SET NOCOUNT ON
-- some procedure body
END
Never before I saw AS dummy:; and now I'm a little confused, I can't find any good explanation what is it and how it works. Could anybody tell me what does it mean this statement? How it works? What is the reason to have it? Any thought would be good to hear. Or, please, advise me some link where I can find good explanation.
This is simply a label, such that could be used in a GOTO statement.
The word "dummy" is unimportant. It's simply trying to create the stored procedure if it doesn't exist, with a minimal amount of text. The content is then filled in with the ALTER.
Conceivably, the dummy text could later be searched for to see if any procedures were created and didn't have their content filled in, to check against failed deployments, etc.
Why do this? Well, it preserve the creation time of the stored procedure in metadata (which can be useful in administration or tracking down problems), and is compatible with versions of SQL Server that lack the CREATE OR ALTER... support.
This might make a little more sense if we add a little formatting to the CREATE:
CREATE PROCEDURE [dbo].[sp_ProcTitle]
AS
dummy:
This is, effectively, an empty procedure with a label called dummy. The user appears to be using this to ensure that the procedure exists first, and the ALTERing it. In older versions of SQL Server, such methods were needed because it didn't support CREATE OR ALTER syntax. As such, if you tried to ALTER a procedure that didn't exist the statement failed, and likewise if you try to CREATE a procedure that already exists it fails.
If you are on a recent version of SQL Server, I'd suggest changing to CREATE OR ALTER and getting rid of the call to sys.sp_executesql.

ALTER PROCEDURE doesn't work within IF statement [duplicate]

i have a situation where i want to check a certain column ( like version number) and then apply a bunch of ddl changes
trouble is i am not able to do it with in a IF BEGIN END block, since DDL statements require a GO separator between them, and TSQL wont allow that.
I am wondering if there is any way around to accomplish this
You don't need to use a full block. A conditional will execute the next statement in its entirety if you don't use a BEGIN/END -- including a single DDL statement. This is equivalent to the behavior of if in Pascal, C, etc. Of course, that means that you will have to re-check your condition over and over and over. It also means that using variables to control the script's behavior is pretty much out of the question.
[Edit: CREATE PROCEDURE doesn't work in the example below, so I changed it to something else and moved CREATE PROCEDURE for a more extended discussion below]
If ((SELECT Version FROM table WHERE... ) <= 15)
CREATE TABLE dbo.MNP (
....
)
GO
If ((SELECT Version FROM table WHERE... ) <= 15)
ALTER TABLE dbo.T1
ALTER COLUMN Field1 AS CHAR(15)
GO
...
Or something like that, depending on what your condition is.
Unfortunately, CREATE/ALTER PROCEDURE and CREATE/ALTER VIEW have special requirements that make it much harder to work with. They are pretty much required to be the only thing in a statement, so you can't combine them with IF at all.
For many scenarios, when you want to "upgrade" your objects, you can work it as a conditional drop followed by a create:
IF(EXISTS(SELECT * FROM sys.objects WHERE type='p' AND object_id = OBJECT_ID('dbo.abc')))
DROP PROCEDURE dbo.abc
GO
CREATE PROCEDURE dbo.abc
AS
...
GO
If you do really need conditional logic to decide what to do, then the only way I know of is to use EXECUTE to run the DDL statements as a string.
If ((SELECT Version FROM table WHERE... ) <= 15)
EXECUTE 'CREATE PROC dbo.abc
AS
....
')
But this is very painful. You have to escape any quotes in the body of the procedure and it's really hard to read.
Depending on the changes that you need to apply, you can see all this can get very ugly fast. The above doesn't even include error checking, which is a royal pain all on its own. This is why hordes of toolmakers make a living by figuring out ways to automate the creation of deployment scripts.
Sorry; there is no easy "right" way that works for everything. This is just something that TSQL supports very poorly. Still, the above should be a good start.
GO is recognised by client tools, not by the server.
You can have CREATEs in your stored procedures or ad-hoc queries with no GO's.
Multiple "IF" statements? You can test then for the success of subsequent DDL statements
Dynamic SQL? EXEC ('ALTER TABLE foo WITH CHECK ADD CONSTRAINT ...')?
As mentioned, GO is a client only batch separator to break down a single SQL text block into batches that are submitted to the SQL Server.

Sharepoint 2013 - Using Stored Procedure (CRUD)

I have below SP:
CREATE PROCEDURE [dbo].[ups_Ins_TblA] #ID int, #Comment nvarchar(max) AS
BEGIN
SET NOCOUNT ON
INSERT INTO [db_assets].[Claim]
(ID,Comment)
Values
(#ID,#Comment)
END
Basically, my question is, is there a way to call this in BCS Sharepoint(Business Connectivity Service) using out-of-the-box functionality? Can I further adjust the SP so that it can be supported with all 'CRUD' operations? Pls suggest ideas?
Note: I have made the table as simple as possible.
I don't want to make a straight-insert from the table because I have to join this to another table where document resides that's why I want to use SP.
I'd been spending almost 2-3days reading and still going on.. If anyone can direct me to the light, pls help? Thank you so much!!
This is a noob mistake. Apologies.
The answer is to write your stored procedure separately and assign it the each operation accordingly (Read Item, read List, Create, Update, Delete).
Yes, there will be 5 sp.
As long as the mapping of identifier is set appropriately, the creation of Lists will not have issue (with CRUD operation enabled).

How to delete all tables from db? Cannot delete from sys.tables

How can I perform this query on whatever way:
delete from sys.tables where is_ms_shipped = 0
What happened is, I executed a very large query and I forgot to put USE directive on top of it, now I got a zillion tables on my master db, and don't want to delete them one by one.
UPDATE: It's a brand new database, so I don't have to care about any previous data, the final result I want to achieve is to reset the master db to factory shipping.
If this is a one-time issue, use SQL Server Management Studio to delete the tables.
If you must run a script very, very carefully use this:
EXEC sp_msforeachtable 'DROP TABLE ?'
One method I've used in the past which is pretty simple and relatively foolproof is to query the system tables / info schema (depending on exact requirements) and have it output the list of commands I want to execute as the results set. Review that, copy & paste, run - quick & easy for a one-time job and because you're still manually hitting the button on the destructive bit, it's (IMHO) harder to trash stuff by mistake.
For example:
select 'drop table ' + name + ';', * from sys.tables where is_ms_shipped = 0
No backups? :-)
One approach may be to create a Database Project in Visual Studio with an initial Database Import. Then delete the tables and synchronize the project back to the database. You can do the deletes en masse with this approach while being "buffered" with a commit phase and UI.
I am fairly certain the above approach can be used to take care of the table relationships as well (although I have not tried in the "master" space). I would also recommend using a VS DB project (or other database management tool that allows schema comparing and synchronization) to make life easier in the future as well as allowing version-able (e.g. with SCM) schema change-tracking.
Oh, and whatever is done, please create a backup first. If nothing else, it is good training :-)
Simplest and shortest way I did was this:
How to Rebuild System Databases in SQL Server 2008
The problem with all other answers here is that it doesn't work, since there are related tables and it refuses to execute.
This one, not only it works but actually is what I am looking for: "Reset to factory defaults" as stated in the question.
Also this one will delete everything, not only tables.
This code could be better but I was trying to be cautious as I wrote it. I think it is easy to follow an easy to tweak for testing before you commit to deleting your tables.
DECLARE
#Prefix VARCHAR(50),
#TableName NVARCHAR(255),
#SQLToFire NVARCHAR(350)
SET #Prefix = 'upgrade_%'
WHILE EXISTS(
SELECT
name
FROM
sys.tables
WHERE
name like #Prefix
)
BEGIN
SELECT
TOP 1 --This query only iterates if you are dropping tables
#TableName = name
FROM
sys.tables
WHERE
name like #Prefix
SET #SQLToFire = 'DROP TABLE ' + #TableName
EXEC sp_executesql #SQLToFire;
END
I did something really similar, and what I wound up doing was using the Tasks--> script database to only script drops for all the database objects of the originally intended database. Meaning the database I was supposed to run the giant script on, which I did run it on. Be sure to include IF Exists in the advanced options, then run that script against the master and BAM, deletes everything that exists in the original target database that also exists in the master, leaving the differences, which should be the original master items.
Not very elegant but as this is a one time task.
WHILE EXISTS(SELECT * FROM sys.tables where is_ms_shipped = 0)
EXEC sp_MSforeachtable 'DROP TABLE ?'
Works fine on this simple test (clearing a on the second loop after failing on the first attempt and proceeding onwards to delete b)
create table a
(
a int primary key
)
go
create table b
(
a int references a (a)
)
insert into a values (1)
insert into b values (1)

Calling a Stored Proc from within a Stored Proc and returning a recordset

I have a Stored Procedure that rolls-back a series of operations. I want to call this from within another SP.
The problem is that the inner SP returns a record set with a single value that indicates the degree of success.
This approach worked well and has some advantages in our context, but in retrospect, I would have done it the conventional way with a Return value or an Output parameter.
I could always change this SP to use this approach and modify the calling code, but a) I don't want to dabble with any more code than I have to, and b) at an intellectual level, I'm curious to see what alternative solution there may be, if any.
How (if at all) can I call this SP and determine the value of the singleton recordset returned?
Thanks
A stored procedure returns a record set like any other, so you can actually do this:
INSERT INTO MyTable (
MyValue
)
EXEC dbo.MyStoredProcedure
The EXEC takes the place of a SELECT statement. To get the value, just SELECT from the table you inserted into. Typically, this would be a temp table.
The other option is to convert the stored procedure that returns a recordset into a function that returns a table.
Ant's approach is probably best if you want to minimize the changes to your system.
Normally you would use a temporary table for that approach since you can't use an exec statement to insert into a table variable.
Here's a variation which will work well if you need to use this for MULTIPLE recordsets.
CREATE TABLE #outsidetable (...)
exec spInsideProcedure
SELECT * FROM #outsidetable
inside spInsideProcedure
INSERT INTO #outsidetable SELECT <blah blah blah>
I tried Ant's approach and it worked a treat:
Declare #Success tinyint
Declare #Response Table (Success int)
Insert into #Response(Success)
Exec Fix_RollbackReturn 12345, 15
Select #Success=Success from #Response
As you can see I used a Table Variable rather than a temporary table because slightly more efficient than a temporary table.
Thanks for all your help guys.
EDIT: It appears that Dave was right after all. That is, my Exec-into-Table-variable approach worked on my SQL2005 development machine, but when moved to the Live (SQL2000) machine it objected, so I had to change to the temporary table approach.
It's a little annoying, especially since in a couple of weeks we are upgrading to SQL2005 across the board(!).

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