I am new to SQL Server. I wrote a simple stored procedure that returns rows with data condition.
Here is my code:
CREATE PROCEDURE test.newArtists
#LastUpdated smalldatetime
AS
BEGIN
SELECT *
FROM ARTIST
WHERE GENERATED > #LastUpdated OR MODIFIED > #LastUpdated;
END
When I execute this stored procedure, it returns 0 rows. like ...
DECLARE #temp DATETIME;
SET #temp = CONVERT (DATETIME, '2016/12/05');
EXEC test.newArtists #LastUpdated = #temp;
However, when I execute the query without using procedure, it returns about 5,000 rows.
DECLARE #temp DATETIME;
SET #temp = CONVERT (DATETIME, '2016/12/05');
SELECT *
FROM ARTIST
WHERE GENERATED > #temp OR MODIFIED > #temp;
I just do not understand whey those two returns different results.
Thanks for explanations!
===================================================
I find the problem. Thanks.
I'am using test schema.
So I connected to test. However, When I use SELECT * FROM ARTIST it does not search test.ARTIST, but ARTIST table which belongs to dbo.
Summary.
The basic problem here is I got 2 tables with name ARTIST.
However, I still do not understand why it automatically look for dbo schema.
I got little experience with MYSQL, but when I connect to a certain schema, it only find objects inside of the schema. Is it normal or should I do some work to set prefix?
Thanks for answers though b
It is always good practice to refer to database objects by a schema
name and the object name, separated by a period (.).
object referred to without an explicit schema name ... will be located by searching the default schema first, followed by the dbo schema
Source: SQL Server Best Practices – Implementation of Database Object Schemas
Dbo is the default schema, it will always go to that one first if the schema is not specified. It is a good practice to always specify the schema in the query especially if you are using more than one. That way it won't waste time looking in the wrong schema first.
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'm working on the next update for StackQL.
One thing I want to do is have the ability to query over several releases. So when I loaded the October data, for example, I didn't delete the old September database. It's still out there. In fact, you can even still query it by including the database name like this:
select top 10 * from SO_Sept09..Posts
This will be even more important as they start providing data for ServerFault and SuperUser.
But I don't like having a whole bunch of databases out there to support this. I'd much rather put all the data in the same database and separate each distinct set into it's own schema. But to make this possible, I need to be able to set a default schema as part of the stored procedure that runs the query, based on a parameter passed to the stored procedure that tells it which database the user selected from a future drop down list to appear in the tool bar.
Queries at StackQL are eventually just passed to the exec() function like this:
exec(#QueryText)
Is there anything I can do either in the stored procedure or prepend to the QueryText string (ala USE [DatabaseName]) to set the default schema used in a query?
There are pieces of how to do this in various places here, but not altogether. The way to do this is:
Make a unique login & user for each schema
Make these users the owners of each different schema.
Set each such user's default schema to be the schema that they own.
Use the syntax EXECUTE ('sql commands') AS USER = 'schema-owner' to execute your SQL commands in the context of that default schema.
The following script demonstrates this:
--====== Create the Login for the User:
CREATE LOGIN [UserTest1] WITH PASSWORD='whatever', DEFAULT_DATABASE=[TestUsers], DEFAULT_LANGUAGE=[us_english]
GO
--====== Make a User for the Login:
CREATE USER [UserTest1] FOR LOGIN [UserTest1]
GO
--====== Make a Schema owned by the User and default to it:
-- (I assume that you already have the schemas)
CREATE SCHEMA [UserTest1] AUTHORIZATION [UserTest1]
GO
ALTER USER [UserTest1] WITH DEFAULT_SCHEMA=[UserTest1]
GO
--====== Make a sProc in dbo
CREATE PROCEDURE [dbo].[TestSchema_Exec] AS
SELECT 'executing in schema [dbo]'
GO
--====== Make a similar sProc in New Schema
CREATE PROCEDURE [UserTest1].[TestSchema_Exec] AS
SELECT 'executing in schema [UserTest1]'
GO
--========= Demonstrate that we can switch Default Schemas:
EXEC('TestSchema_Exec')
EXEC('TestSchema_Exec') AS USER = 'UserTest1'
Other than modifying #QueryText itself, the only thing I can think of is a user's default schema:
ALTER USER SO_Sept09_Reader WITH DEFAULT_SCHEMA = SO_Sept09
...and then connect as a different user for each schema you want to use. Hackity hack.
But if your query is dynamically constructed anyway (and I'm sure you know why that's often not a great idea), it might be easiest to just add a schema placeholder to the query text, and pass the schema name along with the query to a replacement function.
Another possibility is to generated copies of each SP in each schema, the unmodified table name in an SP refers to tables in the same schema.
Note this doesn't work with dynamic SQL inside such an SP:
CREATE PROCEDURE schema_a.SP
#somesql AS varchar(MAX)
AS
BEGIN
EXEC ( #somesql )
END
CREATE PROCEDURE schema_b.SP
#somesql AS varchar(MAX)
AS
BEGIN
EXEC ( #somesql )
END
Won't work, because the schema affinity is lost inside the EXEC.
While this:
CREATE PROCEDURE schema_a.SP
AS
BEGIN
SELECT * FROM tbl -- Will use schema_a.tbl first
END
CREATE PROCEDURE schema_b.SP
AS
BEGIN
SELECT * FROM tbl -- Will use schema_b.tbl first
END
works fine.
Similarly:
EXEC ( 'EXEC schema_a.SP' )
would obviously work fine.
Untried, but: could you combine the different schemas' data into one view, and add a column calling out the schema name?
CREATE VIEW AllPosts AS
SELECT Data1, Data2, 'Sept09' AS Partition FROM SO_Sept09..Posts
UNION ALL
SELECT Data1, Data2, 'Oct09' AS Partition FROM SO_Oct09..Posts
...
SELECT * FROM AllPosts WHERE Partition = 'Sept09'
SELECT * FROM dbo.AllPosts('Sept09') -- if use table-valued function instead
Okay, I have a new way to do this that might work a little better for me. It's a variant on my comment to Michael Petrotta's answer:
But it does give me the idea to maybe have several users and pick the connection string on the fly.
What I will do is have just one user for executing these queries, but I will swap out the connection string on the fly to specify the correct Initial Catalog.
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