I am writing a stored procedure for SQL Server 2008 in which I need to extract information from a set of tables. I do not know ahead of time the structure of those tables. There is another table in the same database that tells me the names and types of the fields in this table.
I am doing this:
declare #sql nvarchar(max)
set #sql = 'select ... into #new_temporary_table ...'
exec sp_executesql #sql
Then I iterate doing:
set #sql = 'insert into #another_temporary_table ... select ... from #new_temporary_table'
exec sp_executesql #sql
After that I drop the temporary table. This happens in a loop, so the table with be created, populated and dropped many times, each time with different columns.
This fails with the error:
Invalid object name: #new_temporary_table.
After some googling I have found that:
The table #new_temporary_table is being created in the scope of the call to exec sp_executesql which is different from the one of my stored proc. This is the reason the next exec sp_executesql cannot find the table. This post explains it:
http://social.msdn.microsoft.com/forums/en-US/transactsql/thread/1dd6a408-4ac5-4193-9284-4fee8880d18a
I could use global temporary tables, which are prepended with ##. I can't do this because multiple stored procs could run at the same time and they would be affecting each other's state
In this article it says that if I find myself in this situation I should change the structure of the database. This is not an option for me:
http://www.sommarskog.se/dynamic_sql.html
One workaround I have found was combining all the select into #new_temporary_table.. and all the insert into ... scripts into one gigantic statement. This works fine but it has some downsides.
If I do print #sql to troubleshoot, the text gets truncated, for example.
Do I have any other option? All ideas are welcome.
You could use global temp tables, but use a context id (such as newid()) as part of the global temp table name.
declare #sql varchar(2000)
declare #contextid varchar(50) = convert(varchar(20), convert(bigint, substring(convert(binary(16), newid()), 1, 4)))
set #sql = 'select getdate() as stuff into ##new_temporary_table_' + #contextid
exec (#sql)
I think it's best to use one single script.
You can change how many characters will print in Tools > Options > Query Results > SQL Server > Results to Text - change "Maximum number of characters..." from 256 to the max (8192).
If it's bigger than 8192, then yes, printing is difficult. But you could try a different option in this case. Instead of PRINT #sql; instead use the following (with Results to Grid):
SELECT sql FROM (SELECT #sql) AS x(sql) FOR XML PATH;
Now you can click on the result, and it opens in a new query window. Well, it's an XML file window, and you can't execute it or see color-coding, and you have to ignore that it changes e.g. > to > to make it valid as XML data, but from here it's easy to eyeball if you're just trying to eyeball it. You can copy and paste it to a real query editor window and do a search and replace for the entitized characters if you like. FWIW I asked for them to make such XML windows real query windows, but this was denied:
http://connect.microsoft.com/SQLServer/feedback/details/425990/ssms-allow-same-semantics-for-xml-docs-as-query-windows
#temp tables (not global) are available in the scope they were created and below.
So you could do something like...
while (your_condition = 1) begin
set #sql = 'select ... into #temp1 ...from blah
exec sp_do_the_inserts'
exec(#sql)
end
The sp_do_the_inserts might look like...
select * into #temp2 from #temp1
....your special logic here....
This assumes you create sp_do_the_inserts beforehand, of course.
Don't know if that serves your need.
Related
My office is changing our linked servers. As a result, I need to get a list of every single view from every database on our instance that points to the current linked server so we can know what needs replaced.
After doing some research online, I came up with this solution to get a list of all the views that reference the linked server:
Create a temp table:
CREATE TABLE [dbo].[#TMP]
(
[DBNAME] NVARCHAR(256) NULL,
[NAME] NVARCHAR(256) NOT NULL,
[DESC] NVARCHAR(MAX) NOT NULL
);
Then, I can take advantage of the sp_msforeachdb procedure to iterate through each database, and store this information in the temporary table:
DECLARE #command varchar(1000)
SELECT #command = 'INSERT INTO #TMP SELECT ''?'' as DBName, OBJECT_NAME(object_id), definition FROM sys.sql_modules WHERE definition LIKE ''%linkedservername%'''
EXEC sp_msforeachdb #command
When I do a SELECT * from #TMP, I see something fishy... the same 5 views are repeated for EVERY database. It's as if it took the first 5 views in a database that had by linked server name, and then just copied it for every database!
Things get even weirder if I modify my select command by changing sys.sql_modules to [?].sys.sql_modules; in this case, rather than getting 565 results, I only get 17!!!
Now, if I take out the INSERT INTO #TMP" part of the command, and run the following:
DECLARE #command varchar(1000)
SELECT #command = 'SELECT ''?'' as DBName, OBJECT_NAME(object_id), definition FROM sys.sql_modules WHERE definition LIKE ''%linkedservername%'''
EXEC sp_msforeachdb #command
The results get even weirder! In one of my databases named "DB_Jobs", in the column for views (there isn't a column name), 3 of the 4 results returns NULL, and the last results returns "SCHTYPEMismatch". Stranger yet, in the definition column, it returns accurate results!!!
Then, if I go to the database and run this:
SELECT OBJECT_NAME(object_id), definition
FROM [DB_Jobs].[sys].[sql_modules]
WHERE definition LIKE '%linkedservername%'
it returns the results perfectly!
What's going on? More importantly, what can I do in my original #command to utilize sp_msforeachdb and correctly return the results I want (and include the database name for each result)?
By the way, I'm on SQL Server 2014.
Sp_msforeachdb is basically a global cursor that gives you access to the each database in turn by referencing [?]. It doesn't execute your command on each db by default. You can see this if you run a simple
EXEC sp_msforeachdb 'select db_name()'
For your first example, you're getting the same views because you're running the command against the same database every time. When you switch to [?].sys.sql_modules you start querying the sys.sql_modules in that database referenced by [?].
The problem with NULLs can be seen by running something like this:
SELECT OBJECT_NAME(object_id), definition FROM [msdb].[sys].[sql_modules] WHERE definition LIKE '%name%'
Run it in MSDB and you'll have a column name full of object names and a column with definitions. Run it in Master and the object names are now NULL even though you have the definitions. OBJECT_NAME() runs in the context of the current database, so you get NULLs unless you happen to have an object_id that matches, but then you're displaying the wrong object name. Definitions is directly referencing the database you want, so you still get them.
To get your query to work as you want it you just need to USE [?] (I'm looking for a definition like %name% because I know it will be there for testing)
CREATE TABLE [dbo].[#TMP](
[DBNAME] NVARCHAR(256) NULL,
[NAME] NVARCHAR(256) NOT NULL,
[DESC] NVARCHAR(MAX) NOT NULL);
DECLARE #command varchar(1000)
SELECT #command = 'USE [?]; INSERT INTO #TMP SELECT ''?'' as DBName, OBJECT_NAME(object_id), definition FROM sys.sql_modules WHERE definition LIKE ''%name%'''
EXEC sp_msforeachdb #command
SELECT * FROM #TMP
I need a way to compare a stored procedure across multiple (hundreds and hundreds) of databases. Not just compare two at a time. It looks like ApexSQL only does two at a time (unless I am mistaken). This won't work because it will take forever. I need to group by the stored procedure so I can identify which groups I can make certain changes to.
I tried the following code solution:
select
'select OBJECT_NAME(object_id), OBJECT_DEFINITION(object_id) from ' +
name + '.sys.procedures where name like ''sp_someProcedure%'' union'
from
master.sys.databases
I then tried to throw the scripts that outputted into a sub select where I do a group by the stored procedure. This doesn't work because for some reason you can't union between multiple databases for sys stuff (unless I am mistaken). Each select statement stays in the context of what you are using. So use databaseOne stays in databaseOne even though the following select statement is select blah blah blah from databaseTwo.
Any thoughts?
Firstly, let's start off topic with a useful article: Is the sp_ prefix still a no-no?. Don't start your SP's name with sp_, it's reserved by Microsoft for system stored procedures. The article discusses further as to why it's a bad idea; but simply put, your SP could just (suddenly) stop working one day, and also it can have a performance hit.
Now, more on topic. You could instead use the undocumented sp sp_msforeachdb. This results in something like:
CREATE TABLE #Procs (ObjectName sysname, ObjectDefination nvarchar(MAX));
DECLARE #SQL nvarchar(MAX);
SET #SQL = N'SELECT OBJECT_NAME(object_id), OBJECT_DEFINITION(object_id)' + NCHAR(10) +
N'FROM [?].sys.procedures' + NCHAR(10) +
N'WHERE [name] LIKE ''sp_someProcedure%'';';
INSERT INTO #Procs
EXEC sp_msforeachdb #SQL;
SELECT *
FROM #Procs;
DROP TABLE #Procs;
I need to TRIM databases as per requirement. So, I'm using below script and giving database names manually. All I need is to automate the script to get database names automatically. Can anyone please suggest how to get the database name automatically.
Use [Sales_backup_2015_05_31_230001_7137975]
Exec [spMaint_TrimTestDB] 1
Go
for Eg:
instead of giving manually Sales_backup_2015_05_31_230001_7137975 I need to get db name automatically
Thanks.
There is a function DB_NAME() that would return the name of the current database if no parameters are passed. Check this.
I guess dynamic SQL might help you to run SP in different databases:
DECLARE #sql nvarchar(max)
SELECT #sql = (
SELECT N'Use '+QUOTENAME([name]) +' Exec [spMaint_TrimTestDB] 1;'
FROM sys.databases
WHERE database_id >= 5 AND [name] like 'Sales_backup%'
FOR XML PATH('')
)
EXEC sp_executesql #sql
This script will create and execute dynamic statement like:
Use [sales_backup_2015] Exec [spMaint_TrimTestDB] 1;
Use [sales_backup_2016] Exec [spMaint_TrimTestDB] 1;
etc...
Observe the following simple SQL code:
CREATE TABLE #tmp (...) -- Here comes the schema
INSERT INTO #tmp
EXEC(#Sql) -- The #Sql is a dynamic query generating result with a known schema
All is good, because we know the schema of the result produced by #Sql.
But what if the schema is unknown? In this case I use Powershell to generate a Sql query like that:
SET #Sql = '
SELECT *
INTO ##MySpecialAndUniquelyNamedGlobalTempTable
FROM ($Query) x
'
EXEC(#Sql)
(I omit some details, but the "spirit" of the code is preserved)
And it works fine, except that there is a severe limitation to what $Query can be - it must be a single SELECT statement.
This is not very good for me, I would like to be able to run any Sql script like that. The problem, is that no longer can I concatenate it to FROM (, it must be executed by EXEC or sp_executesql. But then I have no idea how to collect the results into a table, because I have no idea of the schema of that table.
Is it possible in Sql Server 2012?
Motivation: We have many QA databases across different Sql servers and more often than not I find myself running queries on all of them in order to locate the database most likely to yield best results for my tests. Alas, I am only able to run single SELECT statements, which is inconvenient.
We use SP and OPENROWSET for this purpose.
At first create SP based on a query you need, than use OPENROWSET to get data into temp table:
USE Test
DECLARE #sql nvarchar(max),
#query nvarchar(max)
SET #sql = N'Some query'
IF OBJECT_ID(N'SomeSPname') IS NOT NULL DROP PROCEDURE SomeSPname
SET #query =N'
CREATE PROCEDURE SomeSPname
AS
BEGIN
'+#sql+'
END'
EXEC sp_executesql #query
USE tempdb
IF OBJECT_ID(N'#temp') IS NOT NULL DROP TABLE #temp
SELECT *
INTO #temp
FROM OPENROWSET(
'SQLNCLI',
'Server=SERVER\INSTANCE;Database=Test;Trusted_Connection=yes;',
'EXEC dbo.SomeSPname')
SELECT *
FROM #temp
I have three websites which uses an abstract database structure with tables like: Items, Places, Categories, etc... and stored procedures like GetItemsByCategory, GetRelatedItems, etc... Actually im using exactly the same database structure for these 3 different websites.
From a code perspective im using the same code for all websites (except the HTML which is specific foreach one), and all the common code is in few projects used by all websites, so everytime that i detect a bug (which is in all websites) i just fix it on one place (the common part used by all) and automatically all websites get the fix.
Actually im using Asp.net MVC3 and Sql server.
Everytime i want to extend some funcionality, and i need a new table, stored procedure or something related with database, i have to do the modification in each database.
Do you know any approach that i could use to be able to have the same flexibility and do database modifications only one time for all websites?
Do you think I'm using a good approach or i should use something different in your opinion?
If the databases are on a single server, you could generate the script for the procedure from Management Studio, and make sure to use the option to "check for object existence" (Tools > Options > SQL Server Object Explorer > Scripting). This will yield something like this (most importantly it produces your stored procedure code as something you can execute using dynamic SQL):
USE DBName;
GO
SET ANSI_NULLS ON;
GO
SET QUOTED_IDENTIFIER ON;
GO
IF NOT EXISTS (...)
BEGIN
EXEC dbo.sp_executesql #statement = N'CREATE PROCEDURE dbo.whatever ...
'
END
GO
Now that you have this script, you can modify it to work across multiple databases - you just need to swipe the #statement = portion and re-use it. First you need to stuff the databases where you want this to work into a #table variable (or you can put this in a permanent table, if you want). Then you can build a command to execute in each database, e.g.
DECLARE #dbs TABLE (name SYSNAME);
INSERT #dbs(name) SELECT N'db1';
INSERT #dbs(name) SELECT N'db2';
INSERT #dbs(name) SELECT N'db3';
-- now here is where we re-use the create / alter procedure command from above:
DECLARE #statement NVARCHAR(MAX) = N'CREATE PROCEDURE dbo.whatever ...
';
-- now let's build some dynamic SQL and run it!
DECLARE #sql NVARCHAR(MAX);
SET #sql = N'';
SELECT #sql = #sql + '
EXEC ' + QUOTENAME(name) + '.dbo.sp_executesql N''' + #statement + ''';'
FROM #dbs;
EXEC sys.sp_executesql #sql;
Alternatively, you could create a custom version of my sp_msforeachdb or sp_ineachdb replacements:
Making a more reliable and flexible sp_MSforeachdb
Execute a Command in the Context of Each Database in SQL Server
I used to use a tool called SQLFarms Combine for this, but the tool doesn't seem to exist anymore, or perhaps it has been swallowed up / re-branded by another company. Red Gate has since produced SQL Multi Script that has similar functionality.
If you added a column to all your tables called websiteId you could just have one database. Store the unique websiteId in each site's web.config and just pass it with each request for data. Obviously each site's data is stored with their websiteId so data can be queried per website.
It means a bit of refactoring in your db and any calls to your your db, but once done, you only have one database to maintain.
Of course this is assuming your databases are on the same server...