I want to do a check (if statement) and then create one of two possible procedures.
Right now I am trying to use a IF EXISTS statement inside a CREATE PROCEDURE statement.
CREATE PROCEDURE [dbo].[TestProc]
AS
SET NOCOUNT ON
SET ANSI_NULLS ON
SET QUOTED_IDENTIFIER OFF
IF EXISTS (select * from table)
BEGIN
DECLARE #region NVARCHAR(100)
SELECT *
INTO #TempTable
FROM User
...do something with #TempTable etc..
DROP #TempTable
END
ELSE
BEGIN
DECLARE #region NVARCHAR(100)
SELECT *
INTO #TempTable
FROM User
...do something else with #TempTable etc
DROP #TempTable
END
I get the following 2 errors
There is already an object named 'TempTable' in the database.
The variable name '#region' has already been declared. Variable names must be unique within a query batch or stored procedure.
Either a) Create the temp table first in the stored procedure, then use INSERT INTO (...) SELECT ... to populate it, or b) Use a different name for the temp table in the two branches.
The T-SQL parser is a remarkably simple beast, and control flow doesn't affect its interpretation of which objects exist or not - so if you declare a temp table in one branch of an IF, you can't declare it separately in the other branch - it "exists" whether the control flow enters the IF branch or not.
A Similar argument applies for variables.
Obviously, option a only works if the temp table structures are identical.
Simple example of how control flow is ignored:
if 1=2
begin
declare #a int
end
set #a = 5
print #a
prints 5. Just:
set #a = 5
print #a
produces the error Must declare the scalar variable "#a"., which demonstrates that the declaration (inside the un-followed branch of if) still took effect.
1.You need use two different temp table and before SELECT * INTO statements DROP them
2.Variable need once declared in the body procedure. In your case before IF EXISTS
CREATE PROCEDURE [dbo].[TestProc]
AS
SET NOCOUNT ON
SET ANSI_NULLS ON
SET QUOTED_IDENTIFIER OFF
DECLARE #region NVARCHAR(100)
IF EXISTS(SELECT 1 FROM dbo.test6)
BEGIN
IF OBJECT_ID('tempdb.dbo.#TempTable') IS NOT NULL DROP TABLE dbo.#TempTable
SELECT *
INTO #TempTable
FROM dbo.test6
END
ELSE
BEGIN
IF OBJECT_ID('tempdb.dbo.#TempTable2') IS NOT NULL DROP TABLE dbo.#TempTable2
SELECT *
INTO #TempTable2
FROM dbo.test6
END
Related
I have a stored procedure in other database which is maintained by other team. Assume that it is currently returning 3 columns, and my system only needs those 3 columns
but the other team can add few more columns for their own use which is causing my system to fail.
Other database SP
ALTER PROCEDURE FirstSP
AS
BEGIN
SET NOCOUNT ON;
CREATE TABLE #A (Id INT, Name VARCHAR(200), Amount VARCHAR(100), TestColumn INT)
INSERT INTO #A VALUES
(1,'ABC','23',1), (2,'CDF','35454',2), (3,'hjhj','9809909',3)
SELECT * FROM #A
DROP TABLE #A
END
GO
And below is my query, which was only expecting 3 columns from the source
CREATE TABLE #MyTable (Id INT, Name VARCHAR(200), Amount INT)
INSERT INTO #MyTable
EXEC dbo.FirstSP;
SELECT * FROM #MyTable
DROP TABLE #MyTable
Is there any way I can provide the column list?
This is what I am trying but it seems that I can't use server name as the parameter
DECLARE #ServerName VARCHAR(100) = ##SERVERNAME
SELECT * FROM OPENQUERY(#ServerName,'EXEC dbo.FirstSP')
My whole problem is to just select required columns from the SP. SP can have many columns in future.
Try this:
/*
-----------------------------------------------------------------------
Replace <SERVERNAME>\<INSTANCENAME>], <DATABASENAME> with your names
*/ ------------------------------------------------------------------------
-- First, enable Data Access (One time only)
EXEC sp_serveroption '<SERVERNAME>\<INSTANCENAME>', 'DATA ACCESS', TRUE;
-- Then SELECT just the fields you need
SELECT ID, Name, Amount
FROM OPENQUERY([<SERVERNAME>\<INSTANCENAME>], 'EXEC <DATABASENAME>.dbo.FirstSP')
I would ask the team that develops the stored procedure to create a parameter "Team" or something and slightly change the sp so that it will return the expected columns based on this parameter.
A more cumbersome solution is to use this stored procedure the get the colum names of the (first) result returned by the sp.
sp_describe_first_result_set 'dbo.usp_mySp';
And then use the result to create some dynamic SQL.
I'm trying to alter an existing temp table that was created and populated in the stored procedure calling this one where I'm doing these changes. I can't change the calling stored procedure and I need to add columns to the temp table, so I tried this:
ALTER TABLE #MyTemp
ADD Column1 VARCHAR(100);
UPDATE x
SET Column1 = a.SomeColumn
FROM #MyTemp x
INNER JOIN dbo.AnotherTable a (NOLOCK) ON a.ColumnName = x.ColumnName
WHERE somecondition;
It compiles, but when I run it I get:
Msg 207, Level 16, State 1, Procedure ProcName, Line #
Invalid column name 'Column1'
Looks like this code is not even being executed.
Could someone please tell me if this is possible and how?
Thanks.
You can apparently do this, but you can't insert into the altered temp table in the same scope you alter it. Don't ask me why.
You can use dynamic sql in the the second proc to get to a lower nesting level, or call another proc. Like this:
use tempdb
go
create or alter proc a
as
begin
create table #t(id int)
exec b
select * from #t
end
go
create or alter proc b
as
begin
alter table #t add a int
exec c
end
go
create or alter proc c
as
begin
insert into #t(id,a) values (1,1)
end
go
As David Browne mentioned on his answer above, this can also be achieved by using dynamic sql, but there is a catch, and here is how:
DECLARE #ColName1 NVARCHAR(100)
DECLARE #DynamicSQL NVARCHAR(500)
SET #ColName1='Column1'
SET #DynamicSQL = 'ALTER TABLE #MyTemp ADD ['+ CAST(#ColName1 AS NVARCHAR(100)) +']
NVARCHAR(100) NULL; '
EXEC(#DynamicSQL)
SET #DynamicSQL = 'UPDATE x SET '+ CAST(#ColName1 AS NVARCHAR(100)) + = a.SomeColumn
FROM #MyTemp x INNER JOIN dbo.AnotherTable a (NOLOCK) ON a.ColumnName = x.ColumnName
WHERE somecondition;
EXEC(#DynamicSQL)
If you place the Alter and the Update in the same execution it won't work, they can't be executed at the same time, otherwise is the same problem as the static code all over again. This way is like a simulation of the extra call to another stored proc but without having an extra proc.
The stored procedure is going to have a different scope that when you try to update it after the proc runs. You will need your alter statement to be inside the proc for this to take affect, or bring the contents of the stored proc outside of the stored procedure so your temp table will share the same scope as your update statement.
For example:
CREATE PROC SPX_TEST
AS
SELECT 1 AS ABC INTO #TEMP_A
EXEC SPX_TEST
SELECT * FROM #TEMP_A
Generates an error saying the temp table does not exist.
Is there any good way to do this, or am I just heading in the wrong direction? I would like to create a stored procedure inside an SQL script. I would like to have variables declared at the beginning of the script so that I can create the SPROCs to use in different contexts/servers.Here is what I would like to do (I know this obviously doesn't work, but I'm looking for any ideas of an alternative)..
DECLARE #golbalValue = 'SomeValue'
GO
CREATE PROCEDURE [dbo].[MyStoredProcedure](
AS
BEGIN
SELECT * FROM Mytable WHERE MyCol = #globalValue
END
GO
What you could do is use a scalar function for the variable
create function f ()
returns varchar(20)
as
begin
return 'some value'
end
go
then use it in your procedure
create proc p ()
as
begin
select *
from my_table
where col = f()
end
go
another possibility which is perhaps more appropriate is to use sqlcmd here's an example.
From what I understand, you need to create stored procedures with set value from your parameters. You don't want input parameters in the stored Procedures though. Second, you want to switch database contexts. So I think you'll need a tempTable for your parameters and some dynamic SQL. Try this out:
IF OBJECT_ID('tempdb..#globalParam') IS NOT NULL
DROP TABLE #globalParam;
IF OBJECT_ID('AdventureWorks2012.dbo.myTable') IS NOT NULL
DROP TABLE AdventureWorks2012.dbo.myTable
IF OBJECT_ID('Master..myTable') IS NOT NULL
DROP TABLE Master..mytable
--Create your data tables
SELECT 'SomeValue' AS col1 INTO AdventureWorks2012.dbo.myTable;
SELECT 1000 AS col1 INTO master.dbo.myTable;
CREATE TABLE #globalParam(
ParamName VARCHAR(100),
val SQL_VARIANT --SQL_Variant is designed to hold all data types.
);
--Here are your globalParams
DECLARE #globalParam1 VARCHAR(100) = 'SomeValue';
DECLARE #globalParam2 INT = 1000;
--Load your parameters into a table. Might have to cast some of your parameters to SQL_Variant
INSERT INTO #globalParam
VALUES ('globalParam1',#globalParam1),
('globalParam2',CAST(#globalParam2 AS sql_variant));
GO
--Switch database context
USE AdventureWorks2012
GO
--Variable to hold CREATE PROC
DECLARE #sql VARCHAR(MAX);
--Set #SQL with parameter value from #globalParam
SELECT #sql =
'CREATE PROCEDURE dbo.myStoredProc AS
BEGIN
SELECT * FROM myTable WHERE col1 = ''' + CAST(val AS VARCHAR(100)) + '''
END'
FROM #globalParam
WHERE ParamName = 'globalParam1'
--Execute to create the stored procedure
EXEC(#sql)
--Execute it to see if it works
EXEC dbo.myStoredProc
--Switch context. Repeat same steps
USE master
GO
DECLARE #sql VARCHAR(MAX);
SELECT #sql =
'CREATE PROCEDURE dbo.myStoredProc AS
BEGIN
SELECT * FROM myTable WHERE col1 = ''' + CAST(val AS VARCHAR(100)) + '''
END'
FROM #globalParam
WHERE ParamName = 'globalParam2'
EXEC(#sql)
EXEC dbo.myStoredProc
--Cleanup
DROP PROCEDURE dbo.myStoredProc;
USE AdventureWorks2012
GO
DROP PROCEDURE dbo.myStoredProc;
You cannot do what you want. T-SQL doesn't have the concept of global variables. One method is to store values in a "global" table and then reference them as needed. Something like:
create table GlobalParams (
name varchar(255) not null primary key,
value varchar(255) not null
);
create procedure . . .
begin
. . .
declare #value varchar(255);
select #value = value from Globalparams where name = 'name';
select *
from Mytable
where MyCol = #value;
. . .
end;
Note: this is a simplistic example that only allows variables whose type is a string.
You can also wrap the logic in a user-defined function, so the call looks like:
select *
from Mytable
where MyCol = udf_GlobalLookup('name');
It is rather rare to need global parameters that are shared among different stored procedures. Such a global context can be useful, at times, for complex systems. It is unlikely that you need all this machinery for a simple application. An alternative method, such as just passing the parameters in as arguments, is probably sufficient.
I am trying to create a SP which print the label of my vendor, vendor name. I want the user set the startposition, before the startposition I just simply insert a null value. I want be able to reuse the label sheet.
I have the SP code like this:
Alter PROCEDURE [dbo].[z_sp_APVendorLabel]
(#VendorGroup bGroup ,
#StartPosition int)
AS
BEGIN
SET NOCOUNT ON;
Create table #data_null
(Vendor int,
Name varchar(60)null)
Declare #counter int
SET #counter = 0
WHILE #counter < #StartPosition
BEGIN
UPDATE #data_null SET Vendor='',Name=' '
SET #counter = #counter + 1
END
Create table #detial
(Vendor int,
Name varchar (60)null)
select Vendor, Name into #data from APVM
WHERE VendorGroup= #VendorGroup
select * from #data_null
Union All
select * from #detial
END
It is very simple, but when I test it, I did not get any data.
You're creating the table #data_null, and updating it, but never inserting any rows. If you inspect ##rowcount after each update, you'll see it's zero.
Before you change that loop to insert instead of update, please consider setting up a permanent table to select from. A loop to generate N values on every invocation of the procedure is really not the best use of your server's time, or yours. ;-)
Is there a way to persist a variable across a go?
Declare #bob as varchar(50);
Set #bob = 'SweetDB';
GO
USE #bob --- see note below
GO
INSERT INTO #bob.[dbo].[ProjectVersion] ([DB_Name], [Script]) VALUES (#bob,'1.2')
See this SO question for the 'USE #bob' line.
Use a temporary table:
CREATE TABLE #variables
(
VarName VARCHAR(20) PRIMARY KEY,
Value VARCHAR(255)
)
GO
Insert into #variables Select 'Bob', 'SweetDB'
GO
Select Value From #variables Where VarName = 'Bob'
GO
DROP TABLE #variables
go
The go command is used to split code into separate batches. If that is exactly what you want to do, then you should use it, but it means that the batches are actually separate, and you can't share variables between them.
In your case the solution is simple; you can just remove the go statements, they are not needed in that code.
Side note: You can't use a variable in a use statement, it has to be the name of a database.
I prefer the this answer from this question
Global Variables with GO
Which has the added benefit of being able to do what you originally wanted to do as well.
The caveat is that you need to turn on SQLCMD mode (under Query->SQLCMD) or turn it on by default for all query windows (Tools->Options then Query Results->By Default, open new queries in SQLCMD mode)
Then you can use the following type of code (completely ripped off from that same answer by Oscar E. Fraxedas Tormo)
--Declare the variable
:setvar MYDATABASE master
--Use the variable
USE $(MYDATABASE);
SELECT * FROM [dbo].[refresh_indexes]
GO
--Use again after a GO
SELECT * from $(MYDATABASE).[dbo].[refresh_indexes];
GO
If you are using SQL Server you can setup global variables for entire scripts like:
:setvar sourceDB "lalalallalal"
and use later in script as:
$(sourceDB)
Make sure SQLCMD mode is on in Server Managment Studi, you can do that via top menu Click Query and toggle SQLCMD Mode on.
More on topic can be found here:
MS Documentation
Temp tables are retained over GO statements, so...
SELECT 'value1' as variable1, 'mydatabasename' as DbName INTO #TMP
-- get a variable from the temp table
DECLARE #dbName VARCHAR(10) = (select top 1 #TMP.DbName from #TMP)
EXEC ('USE ' + #dbName)
GO
-- get another variable from the temp table
DECLARE #value1 VARCHAR(10) = (select top 1 #TMP.variable1 from #TMP)
DROP TABLE #TMP
It's not pretty, but it works
Create your own stored procedures which save/load to a temporary table.
MyVariableSave -- Saves variable to temporary table.
MyVariableLoad -- Loads variable from temporary table.
Then you can use this:
print('Test stored procedures for load/save of variables across GO statements:')
declare #MyVariable int = 42
exec dbo.MyVariableSave #Name = 'test', #Value=#MyVariable
print(' - Set #MyVariable = ' + CAST(#MyVariable AS VARCHAR(100)))
print(' - GO statement resets all variables')
GO -- This resets all variables including #MyVariable
declare #MyVariable int
exec dbo.MyVariableLoad 'test', #MyVariable output
print(' - Get #MyVariable = ' + CAST(#MyVariable AS VARCHAR(100)))
Output:
Test stored procedures for load/save of variables across GO statements:
- Set #MyVariable = 42
- GO statement resets all variables
- Get #MyVariable = 42
You can also use these:
exec dbo.MyVariableList -- Lists all variables in the temporary table.
exec dbo.MyVariableDeleteAll -- Deletes all variables in the temporary table.
Output of exec dbo.MyVariableList:
Name Value
test 42
It turns out that being able to list all of the variables in a table is actually quite useful. So even if you do not load a variable later, its great for debugging purposes to see everything in one place.
This uses a temporary table with a ## prefix, so it's just enough to survive a GO statement. It is intended to be used within a single script.
And the stored procedures:
-- Stored procedure to save a variable to a temp table.
CREATE OR ALTER PROCEDURE MyVariableSave
#Name varchar(255),
#Value varchar(MAX)
WITH EXECUTE AS CALLER
AS
BEGIN
SET NOCOUNT ON
IF NOT EXISTS (select TOP 1 * from tempdb.sys.objects where name = '##VariableLoadSave')
BEGIN
DROP TABLE IF EXISTS ##VariableLoadSave
CREATE TABLE ##VariableLoadSave
(
Name varchar(255),
Value varchar(MAX)
)
END
UPDATE ##VariableLoadSave SET Value=#Value WHERE Name=#Name
IF ##ROWCOUNT = 0
INSERT INTO ##VariableLoadSave SELECT #Name, #Value
END
GO
-- Stored procedure to load a variable from a temp table.
CREATE OR ALTER PROCEDURE MyVariableLoad
#Name varchar(255),
#Value varchar(MAX) OUT
WITH EXECUTE AS CALLER
AS
BEGIN
IF EXISTS (select TOP 1 * from tempdb.sys.objects where name = '##VariableLoadSave')
BEGIN
IF NOT EXISTS(SELECT TOP 1 * FROM ##VariableLoadSave WHERE Name=#Name)
BEGIN
declare #ErrorMessage1 as varchar(200) = 'Error: cannot find saved variable to load: ' + #Name
raiserror(#ErrorMessage1, 20, -1) with log
END
SELECT #Value=CAST(Value AS varchar(MAX)) FROM ##VariableLoadSave
WHERE Name=#Name
END
ELSE
BEGIN
declare #ErrorMessage2 as varchar(200) = 'Error: cannot find saved variable to load: ' + #Name
raiserror(#ErrorMessage2, 20, -1) with log
END
END
GO
-- Stored procedure to list all saved variables.
CREATE OR ALTER PROCEDURE MyVariableList
WITH EXECUTE AS CALLER
AS
BEGIN
IF EXISTS (select TOP 1 * from tempdb.sys.objects where name = '##VariableLoadSave')
BEGIN
SELECT * FROM ##VariableLoadSave
ORDER BY Name
END
END
GO
-- Stored procedure to delete all saved variables.
CREATE OR ALTER PROCEDURE MyVariableDeleteAll
WITH EXECUTE AS CALLER
AS
BEGIN
DROP TABLE IF EXISTS ##VariableLoadSave
CREATE TABLE ##VariableLoadSave
(
Name varchar(255),
Value varchar(MAX)
)
END
If you just need a binary yes/no (like if a column exists) then you can use SET NOEXEC ON to disable execution of statements. SET NOEXEC ON works across GO (across batches). But remember to turn EXEC back on with SET NOEXEC OFF at the end of the script.
IF COL_LENGTH('StuffTable', 'EnableGA') IS NOT NULL
SET NOEXEC ON -- script will not do anything when column already exists
ALTER TABLE dbo.StuffTable ADD EnableGA BIT NOT NULL CONSTRAINT DF_StuffTable_EnableGA DEFAULT(0)
ALTER TABLE dbo.StuffTable SET (LOCK_ESCALATION = TABLE)
GO
UPDATE dbo.StuffTable SET EnableGA = 1 WHERE StuffUrl IS NOT NULL
GO
SET NOEXEC OFF
This compiles statements but does not execute them. So you'll still get "compile errors" if you reference schema that doesn't exist. So it works to "turn off" the script 2nd run (what I'm doing), but does not work to turn off parts of the script on 1st run, because you'll still get compile errors if referencing columns or tables that don't exist yet.
You can make use of NOEXEC follow he steps below:
Create table
#temp_procedure_version(procedure_version varchar(5),pointer varchar(20))
insert procedure versions and pointer to the version into a temp table #temp_procedure_version
--example procedure_version pointer
insert into temp_procedure_version values(1.0,'first version')
insert into temp_procedure_version values(2.0,'final version')
then retrieve the procedure version, you can use where condition as in the following statement
Select #ProcedureVersion=ProcedureVersion from #temp_procedure_version where
pointer='first version'
IF (#ProcedureVersion='1.0')
BEGIN
SET NOEXEC OFF --code execution on
END
ELSE
BEGIN
SET NOEXEC ON --code execution off
END
--insert procedure version 1.0 here
Create procedure version 1.0 as.....
SET NOEXEC OFF -- execution is ON
Select #ProcedureVersion=ProcedureVersion from #temp_procedure_version where
pointer='final version'
IF (#ProcedureVersion='2.0')
BEGIN
SET NOEXEC OFF --code execution on
END
ELSE
BEGIN
SET NOEXEC ON --code execution off
END
Create procedure version 2.0 as.....
SET NOEXEC OFF -- execution is ON
--drop the temp table
Drop table #temp_procedure_version