Is it possible to pass a variable out of a SQL query?
I am building up the initial query using a variable. I have added a simplified subset of my query below.
Thanks
declare #query Nvarchar(max)
declare #ColumnName Nvarchar(max)
set #ColumnName = 'MyColumn'
SET #query = 'Select ' + #ColumnName + ' from [MyTable] WHERE [MyCondition]'
EXECUTE sp_executesql #query
Can I return this result as a variable to pass to another query?
Yes. You use an output parameter:
declare #query Nvarchar(max);
declare #ColumnName Nvarchar(max);
declare #outval <type>; -- whatever type
set #ColumnName = 'MyColumn'
set #query = 'Select #outval =' + #ColumnName + ' from [MyTable] where [MyCondition]';
execut sp_executesql #query,
N'#outval <type> output',
#outval = #outval output;
Store the results in table variable and then convert it into XML.
Declare #xml XML
declare #query Nvarchar(max)
declare #ColumnName Nvarchar(max)
set #ColumnName = 'MyColumn'
declare #Table as TABLE(
MyColumn varchar(Max)-- Your Column datatype
)
SET #query = 'Select ' + #ColumnName + ' from [MyTable] WHERE [MyCondition]'
INSERT INTO #Table
EXECUTE sp_executesql #query
select #xml=MyColumn from #Table for XML PATH('')
How you want to pass returned result to other query?
What i can think of create a function return a table and call that function on other query:
CREATE FUNCTION test (#id int)
RETURNS #testTable TABLE(id int)
AS
begin
insert into #testTable select id from #your_table where id = #id
return
end
This will return a table you can check using :
select * from test(2); --will give you a table
If you want to use in a query:
`select * from #second_table where id in (select * from test2(#id parameter))` --- will filter query by id returned by function.
Related
I am trying to execute this query:
declare #tablename varchar(50)
set #tablename = 'test'
select * from #tablename
This produces the following error:
Msg 1087, Level 16, State 1, Line 5
Must declare the table variable "#tablename".
What's the right way to have the table name populated dynamically?
For static queries, like the one in your question, table names and column names need to be static.
For dynamic queries, you should generate the full SQL dynamically, and use sp_executesql to execute it.
Here is an example of a script used to compare data between the same tables of different databases:
Static query:
SELECT * FROM [DB_ONE].[dbo].[ACTY]
EXCEPT
SELECT * FROM [DB_TWO].[dbo].[ACTY]
Since I want to easily change the name of table and schema, I have created this dynamic query:
declare #schema sysname;
declare #table sysname;
declare #query nvarchar(max);
set #schema = 'dbo'
set #table = 'ACTY'
set #query = '
SELECT * FROM [DB_ONE].' + QUOTENAME(#schema) + '.' + QUOTENAME(#table) + '
EXCEPT
SELECT * FROM [DB_TWO].' + QUOTENAME(#schema) + '.' + QUOTENAME(#table);
EXEC sp_executesql #query
Since dynamic queries have many details that need to be considered and they are hard to maintain, I recommend that you read: The curse and blessings of dynamic SQL
Change your last statement to this:
EXEC('SELECT * FROM ' + #tablename)
This is how I do mine in a stored procedure. The first block will declare the variable, and set the table name based on the current year and month name, in this case TEST_2012OCTOBER. I then check if it exists in the database already, and remove if it does. Then the next block will use a SELECT INTO statement to create the table and populate it with records from another table with parameters.
--DECLARE TABLE NAME VARIABLE DYNAMICALLY
DECLARE #table_name varchar(max)
SET #table_name =
(SELECT 'TEST_'
+ DATENAME(YEAR,GETDATE())
+ UPPER(DATENAME(MONTH,GETDATE())) )
--DROP THE TABLE IF IT ALREADY EXISTS
IF EXISTS(SELECT name
FROM sysobjects
WHERE name = #table_name AND xtype = 'U')
BEGIN
EXEC('drop table ' + #table_name)
END
--CREATES TABLE FROM DYNAMIC VARIABLE AND INSERTS ROWS FROM ANOTHER TABLE
EXEC('SELECT * INTO ' + #table_name + ' FROM dbo.MASTER WHERE STATUS_CD = ''A''')
Use:
CREATE PROCEDURE [dbo].[GetByName]
#TableName NVARCHAR(100)
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;
DECLARE #sSQL nvarchar(500);
SELECT #sSQL = N'SELECT * FROM' + QUOTENAME(#TableName);
EXEC sp_executesql #sSQL
END
You can't use a table name for a variable. You'd have to do this instead:
DECLARE #sqlCommand varchar(1000)
SET #sqlCommand = 'SELECT * from yourtable'
EXEC (#sqlCommand)
You'll need to generate the SQL content dynamically:
declare #tablename varchar(50)
set #tablename = 'test'
declare #sql varchar(500)
set #sql = 'select * from ' + #tablename
exec (#sql)
Use sp_executesql to execute any SQL, e.g.
DECLARE #tbl sysname,
#sql nvarchar(4000),
#params nvarchar(4000),
#count int
DECLARE tblcur CURSOR STATIC LOCAL FOR
SELECT object_name(id) FROM syscolumns WHERE name = 'LastUpdated'
ORDER BY 1
OPEN tblcur
WHILE 1 = 1
BEGIN
FETCH tblcur INTO #tbl
IF ##fetch_status <> 0
BREAK
SELECT #sql =
N' SELECT #cnt = COUNT(*) FROM dbo.' + quotename(#tbl) +
N' WHERE LastUpdated BETWEEN #fromdate AND ' +
N' coalesce(#todate, ''99991231'')'
SELECT #params = N'#fromdate datetime, ' +
N'#todate datetime = NULL, ' +
N'#cnt int OUTPUT'
EXEC sp_executesql #sql, #params, '20060101', #cnt = #count OUTPUT
PRINT #tbl + ': ' + convert(varchar(10), #count) + ' modified rows.'
END
DEALLOCATE tblcur
You need to use the SQL Server dynamic SQL:
DECLARE #table NVARCHAR(128),
#sql NVARCHAR(MAX);
SET #table = N'tableName';
SET #sql = N'SELECT * FROM ' + #table;
Use EXEC to execute any SQL:
EXEC (#sql)
Use EXEC sp_executesql to execute any SQL:
EXEC sp_executesql #sql;
Use EXECUTE sp_executesql to execute any SQL:
EXECUTE sp_executesql #sql
Declare #tablename varchar(50)
set #tablename = 'Your table Name'
EXEC('select * from ' + #tablename)
Also, you can use this...
DECLARE #SeqID varchar(150);
DECLARE #TableName varchar(150);
SET #TableName = (Select TableName from Table);
SET #SeqID = 'SELECT NEXT VALUE FOR ' + #TableName + '_Data'
exec (#SeqID)
Declare #fs_e int, #C_Tables CURSOR, #Table varchar(50)
SET #C_Tables = CURSOR FOR
select name from sysobjects where OBJECTPROPERTY(id, N'IsUserTable') = 1 AND name like 'TR_%'
OPEN #C_Tables
FETCH #C_Tables INTO #Table
SELECT #fs_e = sdec.fetch_Status FROM sys.dm_exec_cursors(0) as sdec where sdec.name = '#C_Tables'
WHILE ( #fs_e <> -1)
BEGIN
exec('Select * from ' + #Table)
FETCH #C_Tables INTO #Table
SELECT #fs_e = sdec.fetch_Status FROM sys.dm_exec_cursors(0) as sdec where sdec.name = '#C_Tables'
END
I am trying to write a dynamic query. Let's say i have a table like below, which represents the hierarchy level of a sales agent:
AgentNumber Level1Agent Level2Agent Level3Agent Level4Agent Level5Agent
1122334455 1122334499 1122334488 1122334477 1122334466 1122334455
I want to be able to dynamically select a level based on a specified agent. My EXECUTE statement seems to work correctly, but how do I get the result stored in a variable I can use later? Every answer I have found seems to only get me a success return variable, not the actual query result.
Below is my code:
DECLARE #level INT = 1;
DECLARE #agent CHAR(10) = 1122334455;
DECLARE #colname NVARCHAR(11) = CONCAT('Level',#level,'Agent');
DECLARE #whereclause NVARCHAR(35) = CONCAT('WHERE AgentNumber = ',#agent);
DECLARE #qry NVARCHAR(300) = 'SELECT ' + #colname + ' FROM dbo.TABLE ' + #whereclause;
DECLARE #up NVARCHAR(10);
EXECUTE sp_executesql #qry, #up OUT
SELECT #up
The output of #up is NULL. If I change the last two lines to:
EXECUTE #up = sp_executesql #qry
SELECT #up
Now the output of #up is 0.
I want the output of 1122334499 and I need it stored in a variable that can later be used and inserted into a table.
Here is a fully functional example of how you can do this. Notice this is using a parameterized where clause and quotename around the column name in the dynamic sql to prevent sql injection.
if OBJECT_ID('tempdb..#Agents') is not null
drop table #Agents
create table #Agents
(
AgentNumber char(10)
, Level1Agent char(10)
, Level2Agent char(10)
, Level3Agent char(10)
, Level4Agent char(10)
, Level5Agent char(10)
)
insert #Agents
select '1122334455', '1122334499', '1122334488', '1122334477', '1122334466', '1122334455'
DECLARE #level INT = 3;
DECLARE #agent CHAR(10) = 1122334455;
DECLARE #colname NVARCHAR(11) = CONCAT('Level',#level,'Agent');
declare #agentout char(10)
DECLARE #qry NVARCHAR(300) = 'SELECT #agent_out = ' + quotename(#colname) + ' FROM #Agents WHERE AgentNumber = #agentin';
EXECUTE sp_executesql #qry, N'#agentin char(10), #agent_out char(10) output', #agentin = #agent, #agent_out = #agentout output
select #agentout
You can try this :
DECLARE #level INT = 1;
DECLARE #agent CHAR(10) = 1122334455;
DECLARE #colname NVARCHAR(11) = CONCAT('Level',#level,'Agent');
DECLARE #whereclause NVARCHAR(35) = CONCAT('WHERE AgentNumber = ',#agent);
DECLARE #qry NVARCHAR(300) = 'SELECT #agentout=' + #colname + ' FROM dbo.TABLE ' + #whereclause;
DECLARE #up NVARCHAR(10);
EXECUTE sp_executesql #qry, N'#agentout NVARCHAR(10) OUTPUT', #agentout=#up OUTPUT
SELECT #up
Create a variable table and makes your query insert the results you want there. Something like this:
declare #results table(field1 varchar(max), field2 varchar(max));
declare #sqlStatement varchar(max);
set #sqlStatement = 'insert into #results(field1, field2) select field1, field2 from table';
EXECUTE #sqlStatement;
select * from #results; --It will print the results from your sql statement!
I would like to output the result of the dynamic SQL into a variable called #Count but not sure what the syntax or even the code should like to accomplish this.
The code looks as follows:
declare #tab nvarchar(255) = 'Person.person'
declare #Count int
declare #SQL nvarchar(max) = 'select count(*) from '+ #tab
exec(#SQl)
select #Count
thank you
Here's another way to do it that also safely addresses the SQL Injection isuues:
/* Counts the number of rows from any non-system Table, *SAFELY* */
-- The table name passed
DECLARE #PassedTableName as NVarchar(255) = 'Person.Person';
-- Make sure this isn't a SQL Injection attempt
DECLARE #ActualTableName AS NVarchar(255)
SELECT #ActualTableName = TABLE_SCHEMA + '.' + TABLE_NAME
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_NAME = PARSENAME(#PassedTableName,1)
AND TABLE_SCHEMA = PARSENAME(#PassedTableName,2)
-- make a temp table to hold the results
CREATE TABLE #tmp( cnt INT );
-- create the dynamic SQL
DECLARE #sql AS NVARCHAR(MAX)
SELECT #sql = 'SELECT COUNT(*) FROM ' + #ActualTableName + ';'
-- execute it and store the output into the temp table
INSERT INTO #tmp( cnt )
EXEC(#SQL);
-- Now, finally, we can get it into a local variable
DECLARE #result AS INT;
SELECT #result = cnt FROM #tmp;
You can utilize sp_executesql to execute your count() query, and output it #Count.
Try this:
-- Set the table to count from
declare #tab nvarchar(255) = 'Person.person'
-- Assign the SQL query
declare #SQL nvarchar(255) = N'SELECT count(*) FROM ' + #tab
-- Pepare for sp_executesql
declare #Count int
declare #Params nvarchar(100) = N'#Count int output'
-- Set the count to #Count
exec sp_executesql #SQL, #Params, #Count=#Count output
-- Output #Count
select #Count
One last thing: Person.person looks like you might be trying to reference a person column from a Person table. But the above query is a literal representation of what it looks like you're trying to achieve in your question.
The below question is pretty much identical to what you are asking here.
sp_executeSql with output parameter
DECLARE #retval int
DECLARE #sSQL nvarchar(500);
DECLARE #ParmDefinition nvarchar(500);
DECLARE #tablename nvarchar(50)
SELECT #tablename = N'products'
SELECT #sSQL = N'SELECT #retvalOUT = MAX(ID) FROM ' + #tablename;
SET #ParmDefinition = N'#retvalOUT int OUTPUT';
EXEC sp_executesql #sSQL, #ParmDefinition, #retvalOUT=#retval OUTPUT;
SELECT #retval;
is there a way to store the results of an exec statement in a varchar?
DECLARE #TableName varchar(100)
DECLARE #ExecStatement varchar(max)
DECLARE #PromotionXML varchar(max)
SET #TableName = 'Feeds'
Set #ExecStatement = (
'
SET #PromotionXML = (
SELECT
*
FROM
' + #TableName + ' for xml auto, elements
)'
)
exec #ExecStatement
select #PromotionXML
You need to use sp_executesql, not EXEC, since you need to treat the inner variable as an output parameter (which you can't do with EXEC). Also all of these parameters should be NVARCHAR, not VARCHAR (though I'm curious why you aren't returning the xml as XML).
DECLARE
#TableName NVARCHAR(512),
#sql NVARCHAR(MAX),
#xml NVARCHAR(MAX);
SET #TableName = N'dbo.Feeds';
SET #sql = N'SELECT #xml = CONVERT(NVARCHAR(MAX), (
SELECT * FROM ' + #TableName + ' FOR XML AUTO, ELEMENTS));';
EXEC sp_executesql #sql, N'#xml NVARCHAR(MAX) OUTPUT', #xml OUTPUT;
SELECT #xml;
I try to create a stored procedure to update a table record whose sql statement is dynamically created. I wrote some codes but am stoped in to run this query dynamically, How can i run this query or is there a better solution for this problem.
How this SP work?=> I send the columns names,values and datatype of the record that need update to SP like below
<e columnName=''PaymentStatus'' value=''99'' type=''nvarchar''/>
<e columnName=''HotelProvider'' value=''GAT2'' type=''nvarchar''/>
Then travel the nodes and create an Update statement, but can't execute it :))
I am giving a part of SP to understand the question better.
DECLARE #UpdateXml xml = '
<xml>
<e columnName=''PaymentStatus'' value=''99'' type=''nvarchar''/>
<e columnName=''HotelProvider'' value=''GAT2'' type=''nvarchar''/>
</xml>';
DROP TABLE ##UpdateFields
SELECT
t.c.value('#columnName', 'varchar(max)') AS ColumnName,
t.c.value('#value', 'varchar(max)') AS Value,
t.c.value('#property', 'varchar(max)') AS PropertyOf,
t.c.value('#type', 'varchar(max)') AS ColumnType
INTO ##UpdateFields
from #UpdateXml.nodes('/xml/e') as t(c)
DECLARE #SQL nvarchar(MAX) = 'UPDATE HotelBooking ';
DECLARE #SQLUpdatePart nvarchar(MAX);
SET #SQLUpdatePart = 'SET ';
SELECT #SQLUpdatePart= #SQLUpdatePart+ColumnName +'='+'#QP_'+ColumnName+',' FROM ##UpdateFields WHERE PropertyOf IS NULL;
DECLARE #SQLWherePart nvarchar(MAX);
SET #SQLWherePart = ' WHERE Id=2';
DECLARE #ParmDefinition nvarchar(MAX)='';
SELECT #ParmDefinition = #ParmDefinition+'#QP_'+ColumnName+' '+ColumnType+',' FROM ##UpdateFields;
SELECT #ParmDefinition
SELECT #SQL + #SQLUpdatePart + #SQLWHerePart;
Last two select statements results are:
#QP_PaymentStatus nvarchar,#QP_HotelProvider nvarchar,#QP_TransactionId uniqueidentifier,#QP_UpdatedDate datetime
and
UPDATE HotelBooking SET PaymentStatus=#QP_PaymentStatus,HotelProvider=#QP_HotelProvider,UpdatedDate=#QP_UpdatedDate,TransactionId=#QP_TransactionId WHERE Id=2
Now How can I give the #QP parameters to sp_executesql() method dynamically?
You can do it by wrapping sp_executesql call in another exec:
declare #updateStr nvarchar(1000)
-- #updateStr = N'select * from ATable where ID = #p1'
set #updateStr = N'N''select * from ATable where ID = #p1'''
declare #paramStr nvarchar(100)
-- #paramStr = N'#p1 int'
set #paramStr = N'N''#p1 int'''
declare #actualParameters nvarchar(100)
set #actualParameters = N'#p1 = 10'
-- Concatenate parts of query into a variable
declare #sql nvarchar(max)
set #sql = N'sp_executesql ' + #updateStr + ',' + #paramStr + ', ' + #actualParameters
-- And voila!
exec (#sql)