I have a procedure in which there are calculations being done and the final result is inserted into a permanent table. I want to remove the permanent table and I cannot use Temp table as well. So i want to use a dynamic table name, which is stored in a variable:
Current scenario:
Insert into xyz_table
Select col1,col2,sum(col3)
from BaseTable
(In reality, there are lot of columns and a lot of calculations)
What I want:
Select col1,col2,sum(col3) into #DynamicTableName
from BaseTable
where the name of the table would be dynamic in nature i.e.,
#DynamicTableName = 'xyz ' + cast(convert(date,getdate()) as nvarchar)+' '+convert(nvarchar(5),getdate(),108)
It will have date and time in its name every time the procedure is run.
I want to use this name in the "Select * into statement"
How can I achieve this?
i tried it with the some short code. But since my procedure has a lot of calculations and UNIONS , I cannot use that code for this. Any help would be appreciated.
declare #tablename nvarchar(30)= 'xyz ' + cast(convert(date,getdate()) as nvarchar)+' '+convert(nvarchar(5),getdate(),108)
declare #SQL_Statement nvarchar(100)
declare #SQL_Statement2 nvarchar(100)
declare #dropstatement nvarchar(100)
SET #SQL_Statement = N'SELECT * Into ' +'['+#tablename +'] '+'FROM '+ 'dimBranch'
print #SQL_Statement
EXECUTE sp_executesql #SQL_Statement
SET #SQL_Statement= N'select * from ' + '['+#tablename + '] '
print #SQL_Statement
EXECUTE sp_executesql #SQL_Statement
set #dropstatement = 'DROP TABLE' + '['+#tablename + '] '
PRINT #dropstatement
exec sp_executesql #dropstatement
Reason why I want this is because I use this procedure in ETL job as well as in SSRS report. And if someone runs the package and the SSRS report at the same time, the incorrect or weird data gets stored in the table. Therefore I need a dynamic name of the table with date and time.
You can't parameterize an identifier in SQL, only a value
--yes
select * from table where column = #value
--no
select * from #tablename where #columnname = #value
The only thin you can do to make these things dynamic is to build an sql string and execute it dynamically, but your code is already doing this with sp_executesql
More telling is your complaint at the bottom of your question, that if the procedure is invoked simultaneously it gives problems. Perhaps you should consider using local table variables for temporary data storage that the report is using rather than pushing data back into the db
DECLARE #temp TABLE(id INT, name varchar100);
INSERT INTO #temp SELECT personid, firstname FROM person;
-- work with temp data
select count(*) from #temp;
--when #temp goes out of scope it is lost,
--no other procedure invoked simultaneously can access this procedure'a #temp
Consider a local temp table, which is automatically session scoped without the need for dynamic SQL. For example:
SELECT *
INTO #YourTempTable
FROM dimBranch;
The local temp table will automatically be dropped when the proc completes so there is no need for an explict drop in the proc code.
Related
I am currently moving a SAS process to SQL. Within the SAS process, I leverage macros to create a multitude of tables.
I am trying to leverage the CREATE FUNCTION function within SQL to mimic this process, however I am stuck. I have three arguments, the server name, the name of the new table and the table where it should select from. I'm not sure what I should specify as what I am returning as I'm not looking to return anything, just create tables.
CREATE FUNCTION dbo.functionname (#server VARCHAR(250), #name VARCHAR(250), #table VARCHAR(250))
RETURN (???)
AS BEGIN
SELECT *
INTO #server.dbo.#nm
FROM #table
RETURN
END
This is what I have come up with so far. My SELECT statement wouldn't actually be *, I just put that for simplicity sake for this question.
UPDATE: In this instance, using a stored procedure is not an option as permissions have been limited.
You can create a dynamic SQL script as follows
declare #newtable sysname = 'T003',
#sourcetable sysname = 'sys.tables'
declare #sql nvarchar(max)
set #sql = N'select * into ' + #newtable + ' from ' + #sourcetable + ';'
set #sql = #sql + N'select * from ' + #newtable
exec sp_executesql #sql
Then you can use it in a stored procedure
To return data from new table, the table type must be known before. In this case it is not possible, so developer cannot create the function return type
Or create a function just to create the table and insert data into it. But return fail or success, etc
Then select from the new table using a dynamic SQL again
I need to transfer data from a linked server to our main SQL server. The issue is, that the table name changes everyday.
I have looked around this site to find out if it is even possible to have a variable database name, which it is, but also to see if it is possible to have variables in a OPENQUERY, which it also is.
But i am struggling to combine those needs, so i have a variable table name in a OPENQUERY.
I need something like this:
Declare #LinkedServer as varchar(max) = 'LinkedServer'
Declare #TName as varchar(max) = 'TName'+substring(cast(cast(getdate() as date) as
varchar(50)),1,4)+substring(cast(cast(getdate() as date) as
varchar(50)),6,2)+substring(cast(cast(getdate() as date) as
varchar(50)),9,2)
SELECT * FROM OPENQUERY(#LinkedServer, 'SELECT * FROM dbo.#TName')
Is there any way i can make a variable table name in a OPENQUERY ?
Thank you for your help.
/Mikkel
I'd write a synonym which gets updated every day before you kick off your data extraction job. Then you don't need to be updating (potentially a tonne of) references.
CREATE SYNONYM LinkedTableA
FOR
ServerName.DBName.dbo.TName20170331
SELECT * FROM LinkedTableA
The answer i have, is this:
USE [DataBase]
GO
DROP SYNONYM [dbo].[eCallByCallStat]
GO
declare #tablename varchar(50)
set #tablename = 'Server1..dbo.eCallByCallStat'+substring(cast(cast(getdate()-1 as date) as varchar(50)),1,4)+substring(cast(cast(getdate()-1 as date) as varchar(50)),6,2)+substring(cast(cast(getdate()-1 as date) as varchar(50)),9,2)
declare #sql varchar(500)
set #sql = 'CREATE SYNONYM [dbo].[eCallByCallStat] FOR ' + #tablename
exec (#sql)
This will run everymorning updating the table name in the synonym, and then we will insert that data into a prober table so we have all the data.
I'm inserting data into a temp table and querying the temp table fails
DECLARE #SQLQuery AS NVARCHAR(500)
SET #SQLQuery = 'SELECT Top 100 *
INTO #tempTable
FROM ' + #origDB + '.dbo.' + #origTable + ' o WITH (NOLOCK) '
EXECUTE sp_executesql #SQLQuery
and when I try to query the temp table , like so
select * from #tempTable
I get the following error :
Invalid object name '#tempTable'.
Courtesy of MSDN
The problem that you have is with the scope. The TEMP table is creatd at the scope of the EXEC() method and hence it is not available after the function returns. To fix this, create your temp table before calling EXEC() and use an INSERT INTO instead of SELECT INTO.
As others have said, the scope of a temporary table is limited to the session context in which it is created - a stored procedure runs in its own context.
You could use a global temporary table ##tempTable, but it's generally a bad idea as it would be available to other sessions than the one creating it.
There is this query that I keep using over and over:
SELECT column_name, count(column_name) FROM table_name GROUP by column_name ORDER BY COUNT(column_name) DESC
I use this to check which different values there are in a column and how often they occur.
Because I use this query so often and it's repeating the same 4 times: column_name, I was like: why not make a stored procedure:
CREATE PROCEDURE countcv #table_name VARCHAR(50),#column_name VARCHAR(50)
AS
BEGIN
SELECT #column_name,COUNT(#column_name) FROM #table_name GROUP BY #column_name ORDER BY COUNT(#column_name)
END
Here is where I get stuck, I can not manage to get a variable tablename:
Must declare the table variable "#table_name"
I believe that #Julien Vavasseur and #Dark Knight has already addressed to your question.
However, I would like to add here that, Sql Server 2008 introduced Table-Valued Parameter by using which we can pass table type variable to the stored procedures. e.g.
Assuming you have a table by the name tblTest with the below columns
ID INT,
Name VARCHAR(50)
Step 1: Declare a new table User Defined Type
CREATE TYPE tblTestType AS TABLE
(
ID INT,
Name VARCHAR(50)
)
Step 2: Create a STORED PROCEDURE that has tblTestType as parameter
CREATE PROCEDURE countcv
(
#tblName tblTestType readonly
)
AS
INSERT INTO tblTest (ID, Name)
SELECT ID, Name
FROM
#tblName;
Then you can use DataTable (if you are using C#) and pass this data table as a parameter to the Stored Procedure.(you can find an example in the link I provided).
There is no way to do it directly. You need to use dynamicSQL approach. Assuming you pass correct table and column names. Below one should work.
CREATE PROCEDURE countcv #table_name VARCHAR(50),#column_name VARCHAR(50)
AS
BEGIN
declare #SQL nvarchar(max)
set #SQL = 'SELECT '+#column_name+',COUNT('+#column_name+')
FROM '+#table_name+'
GROUP BY '+#column_name+'
ORDER BY COUNT('+#column_name+')'
EXEC sp_executesql #SQL
END
If you want to do something like this, you must use dynamic SQL:
CREATE PROCEDURE countcv #table_name sysname, #column_name sysname
AS
BEGIN
Declare #sql nvarchar(max)
Set #sql = 'SELECT ' + QUOTENAME(#column_name)+', COUNT(' + QUOTENAME(#column_name)+')
FROM ' + QUOTENAME(#table_name)+'
GROUP BY ' + QUOTENAME(#column_name)+' ORDER BY COUNT(' + QUOTENAME(#column_name)+')'
EXEC sp_executesql #sql
END
Use sysname for data type for column and table names (buitin datatype for object names, alias to nvarchar(128))
Use QUOTENAME to add delimeter to column and table names
I want to create a SQL tabled-value function that will receive a query as n parameter through my API. In my function I want execute that query. The query will be a SELECT statement.
This is what I have done so far and what to achieve but it is not the correct way to do so.
CREATE FUNCTION CUSTOM_EXPORT_RESULTS (
#query varchar(max),
#guid uniqueidentifier,
#tableName varchar(200))
RETURNS TABLE
AS
RETURN
(
-- Execute query into a table
SELECT *
INTO #tableName
FROM (
EXEC(#query)
)
)
GO
Please suggest the correct way!
Try this one -
CREATE PROCEDURE dbo.sp_CUSTOM_EXPORT_RESULTS
#query NVARCHAR(MAX) = 'SELECT * FROM dbo.test'
, #guid UNIQUEIDENTIFIER
, #tableName VARCHAR(200) = 'test2'
AS BEGIN
SELECT #query =
REPLACE(#query,
'FROM',
'INTO [' + #tableName + '] FROM')
DECLARE #SQL NVARCHAR(MAX)
SELECT #SQL = '
IF OBJECT_ID (N''' + #tableName + ''') IS NOT NULL
DROP TABLE [' + #tableName + ']
' + #query
PRINT #SQL
EXEC sys.sp_executesql #SQL
RETURN 0
END
GO
Output -
IF OBJECT_ID (N'test2') IS NOT NULL
DROP TABLE [test2]
SELECT * INTO [test2] FROM dbo.test
What I see in your question is encapsulation of:
taking a dynamic SQL expression
executing it to fill a parametrized table
Why do you want to have such an encapsulation?
First, this can have a negative impact on your database performance. Please read this on EXEC() and sp_executesql() . I hope your SP won't be called from multiple parts of your application, because this WILL get you into trouble, at least performance-wise.
Another thing is - how and where are you constructing your SQL? Obviously you do it somewhere else and it seems its manually created. If we're talking about a contemporary application, there are lot of OR/M solutions for this and manual construction of TSQL in runtime should be always avoided if possible. Not to mention EXEC is not guarding you against any form of SQL injection attacks. However, if all of this is a part of some database administration TSQL bundle, forget his paragraph.
At the end, if you want to simply load a new table from some existing table (or part of it) as a part of some administration task in TSQL, consider issuing a SELECT ... INTO ... This will create a new target table structure for you (omitting indexes and constraints) and copy the data. SELECT INTO will outperform INSERT INTO SELECT because SELECT INTO gets minimally logged.
I hope this will get you (and others) at least a bit on the right track.
You can use stored procedure as well, here is the code that you can try.
CREATE FUNCTION CUSTOM_EXPORT_RESULTS
(
#query varchar(max),
#guid uniqueidentifier,
#tableName varchar(200)
)
RETURNS TABLE
AS
RETURN
(
declare #strQuery nvarchar(max)
-- Execute query into a table
SET #strQuery = REPLACE(#query,'FROM', 'INTO '+#tableName+' FROM')
exec sp_executesql #strQuery
)
GO