Currently I have a working version of a dynamic SQL query without any variables except one (#ColumnHeader). And am able to get the desired result being a collection of column names in one line separated by comma.
select #ColumnHeader = COALESCE(#ColumnHeader+',','') + '''' + column_name + ''''
from databaseName.Information_Schema.Columns
where table_name = 'Dates'
I am trying to add variables for Database_information_schema and TableName.
DECLARE #ColumnHeader varchar(8000)
DECLARE #Database_Information_SchemaColumns varchar(8000) = 'DatabaseName2.Information_Schema.Columns'
DECLARE #TableName varchar(8000) = 'dates'
DECLARE #sqlQuery as nvarchar(max) = 'Select ' + #ColumnHeader + '= COALESCE(' + #ColumnHeader+ +''','','''')+ ''''''''+column_name+'''''''' from ' + #Database_Information_SchemaColumns + 'where table_name = '''+ #TableName + ''''
Print #sqlQuery
EXEC sp_executesql #sqlQuery;
I am getting Null values and am not sure whats wrong here.
What follows is some working code. I explain the changes required:
You are trying to assign a parameter using dynamic SQL, therefore the parameter needs to be part of the dynamic SQL string, not concatenated with it.
To assign a parameter using dynamic SQL you have to pass it in/out of sp_executesql because the context the dynamic SQL is running under cannot see the parameters declared.
While this is not necessary, I have renamed the internal parameter so that its clear which parameter belongs in which scope. However both could use the same name if desired.
You were missing a space before your where.
I recommend using varchar(max) and nvarchar(max) as there is no need to risk running into the 8k limit.
Use quotename for any database, schema, table or column names to protect against injection.
Use the sysname datatype where a system name is being stored
Split all system names into parts to allow the use of quotename
DECLARE #ColumnHeader varchar(max)
, #Database_Information_Database sysname = 'DatabaseName2'
, #Database_Information_Schema sysname = 'Information_Schema'
, #Database_Information_Columns sysname = 'Columns'
, #TableName sysname = 'dates';
DECLARE #sqlQuery nvarchar(max) = 'select #ColumnHeaderInteral = COALESCE(#ColumnHeaderInteral,'','','''') + '''''''' + column_name + '''''''' from '
+ quotename(#Database_Information_Database) + '.'
+ quotename(#Database_Information_Schema) + '.'
+ quotename(#Database_Information_Columns)
+ ' where quotename(table_name) = ''' + quotename(#TableName) + '''';
PRINT #sqlQuery;
EXEC sp_executesql #sqlQuery, N'#ColumnHeaderInteral varchar(max) output', #ColumnHeaderInteral = #ColumnHeader out;
SELECT #ColumnHeader;
Official Documentation
Related
I have searched and searched and cannot work out how to resolve my problem. I am actually not sure it is possible but thought I'd post here and check.
The issue:
I have a stored procedure where I make the following call (there are 2 because I was trying different things but both fail):
SET #olddate = '1606'
SET #newdate = '1706'
SET #TableName = 'sometablename'
SET #sql = 'SP_RENAME ''[DBName' + #olddate + '.dbo.' + #TableName + #olddate +'].[ColumnName' + #olddate + 'restofname]'',''[ColumnName' + #newdate + 'restofname]'''
EXECUTE sp_executesql #sql
Other option:
SET #olddate = '1606'
SET #newdate = '1706'
SET #TableName = 'sometablename'
SET #old = '[DBName' + #olddate + '.dbo.' + #TableName + #olddate+']."[ColumnName' + #olddate + 'restofname]"'
SET #new = 'ColumnName' + #newdate + 'restofname'
EXECUTE sp_rename #objname = #old,#newname = #new, #objtype = 'COLUMN'
I saved this in a stored procedure, and then ran it in another query which has a different database context and got the following error for the first:
No item by the name of '[DBName.dbo.TableName.ColumnName]' could be found in the current database '[Other database]', given that #itemtype was input as '(null)'.
and this for the second:
Either the parameter #objname is ambiguous or the claimed #objtype (COLUMN) is wrong.
Now, what I'm wondering is: can I even do this? write a stored procedure that runs sp_rename in a table in one database and then call that stored procedure from another database?
I've also tried every permutation of putting open and closed brackets, [ and ] around parts of my old and new column names. Also tried putting N before the string. It's a bit of trial and error though and thus far nothing has worked.
You cannot put your DBName and schemaName and tablename into one bracket [ ] You need to enclose each with a bracket. And dont use brackets around you new name since it will take these brackets into the name. Its a string so you can just put spaces and what you like into your name.
declare #TableName nvarchar(max)
declare #ColumName nvarchar(max)
declare #NewColumn nvarchar(max)
declare #sql nvarchar(max)
SET #NewColumn = 'newtest'
SET #ColumName = 'test'
SET #TableName = 'trassor'
SET #sql = 'SP_RENAME ''[YOURDBNAME].[YOURSCHEMANAME].['+ #TableName +'].['+#ColumName+']'', '''+#NewColumn+''', ''COLUMN'''
/* SET #sql = 'SP_RENAME ''[LegogSpass].[dbo].['+ #TableName +'].['+#ColumName+']'', '''+#NewColumn+''', ''COLUMN''' */
PRINT #SQL
EXECUTE sp_executesql #sql
First of all use a select #sql query before the sp_executesql statement to view how the dynamic statement has been formed.
This gives you an understanding of the error.
In your case the brackets have been placed in a wrong way.
Either remove them or add individually to dbname,schemaname,tablename and column.
Also, you were missing the 'column' at the end of the sp_rename statement.
declare #sql nvarchar(max),#olddate varchar(10),#newdate varchar(10),#TableName varchar(100)
SET #olddate = '1606'
SET #newdate = '1706'
SET #TableName = 'sometablename'
SET #sql = 'SP_RENAME ''DBName' + #olddate + '.dbo.' + #TableName + #olddate +'.ColumnName' + #olddate + 'restofname'',''ColumnName' + #newdate + 'restofname'',''Column'''
select #sql
EXECUTE sp_executesql #sql
Thanks for all the help. I actually figured out the issue subsequently. I know the brackets were wrong but that wasn't the issue (as I tried all sorts of different combinations of brackets and none of them worked).
set #old = #TableName +'.[ColumnName' + #olddate + 'restofname]'
set #new = 'ColumnName' + #newdate + 'restofname'
execute ('use DBName exec sp_rename ''' + #old + ''', ''' + #new + ''', ''COLUMN''')
The trick was to include "Use Database" within the execute statement.
Below is my procedure. It is working fine.
Create PROCEDURE [dbo].[spCompanyName]
(
#CompanyName VARCHAR(100))
AS
Begin
DECLARE #sql VARCHAR(MAX)
SET #sql = ' Select EmpID,CompanyName FROM Employee' + CHAR(13) + CHAR(10)
IF len(#CompanyName) > 0
BEGIN
SET #sql = #sql + ' Where (RTRIM(LTRIM(CompanyName)) like ''' + #CompanyName + '%'') ' + char(13) + char(10)
END
PRINT #SQL
EXEC(#sql)
End
exec spCompanyName #CompanyName='So Unique, formerly Sofia''''s'
I need Wherever single quote is there in companyname,if I pass 8 quotes in single quotes I need output.above procedure where do I need to change.
Eg:
exec spCompanyName #CompanyName='So Unique, formerly Sofia''''''''s'
exec spCompanyName #CompanyName='Absolute''''''''s,Strategy''''''''s'
Don't think "I'll throw away all of the useful features of using parameters to separate data from code and start manually trying to protect strings" - keep using parameters.
Rather than
EXEC(#sql)
Have:
EXEC sp_executesql #sql,N'#CompanyName varchar(100)',#CompanyName = #CompanyName
And change:
SET #sql = #sql + ' Where (RTRIM(LTRIM(CompanyName)) like ''' + #CompanyName + '%'') ' + char(13) + char(10)
to:
SET #sql = #sql + ' Where (RTRIM(LTRIM(CompanyName)) like #CompanyName + ''%'') ' + char(13) + char(10)
Or, in the alternative, consider just writing a normal query, no dynamic SQL:
Create PROCEDURE [dbo].[spCompanyName]
(
#CompanyName VARCHAR(100))
WITH RECOMPILE
AS
Begin
Select EmpID,CompanyName FROM Employee
Where RTRIM(LTRIM(CompanyName)) like #CompanyName + '%' or
#CompanyName is null
End
Assuming you're using SQL Server 2008 (with particular patch levels) or later, as specified in Erland Sommarskog's Dynamic Search Conditions in T-SQL
If you are going to create a new stored procedure for this feature then you can have this in much better way then dynamic.
You should execute different select queries based on if CompanyName is passed or not.
You can simply the stored procedure as following.
Create PROCEDURE [dbo].[spCompanyName]
(
#CompanyName VARCHAR(100))
AS
Begin
IF LEN(#CompanyName) > 0
BEGIN
Select EmpID,CompanyName FROM Employee WHERE RTRIM(LTRIM(CompanyName)) like '' + #CompanyName + '%'
END
ELSE
BEGIN
Select EmpID,CompanyName FROM Employee
END
END
I am not sure why you need to pass so many single quotes in the parameter value but to me it looks like you can execute the procedure with following simple way.
EXEC spCompanyName #CompanyName='So Unique, formerly Sofia''s'
EXEC spCompanyName #CompanyName='Absolute''s,Strategy''s'
This should help you finding your solution.
Here is what i'm trying to do. I'm trying to create a stored procedure where I could just enter the name of the table, column, and column value and it will delete any records associated with that value in that table. Is there a simple way to do this? I don't know too much about SQL and still learning about it.
Here is what I have so far.
ALTER PROCEDURE [dbo].[name of stored procedure]
#TABLE_NAME varchar(50),
#COLUMN_NAME varchar(50),
#VALUE varchar(5)
AS
BEGIN
SET NOCOUNT ON;
DECLARE #RowsDeleted int;
DECLARE #sql VARCHAR(500);
SET #sql = 'DELETE FROM (name of table).' + #TABLE_NAME + ' WHERE ' + #COLUMN_NAME + '=' + '#VALUE'
EXEC(#sql)
SET #RowsDeleted=##ROWCOUNT
END
GO
Couple issues
First, you don't need (name of table)
SET #sql = 'DELETE FROM ' + #TABLE_NAME + etc.
In general you should try to include the appropriate schema prefix
SET #sql = 'DELETE FROM dbo.' + #TABLE_NAME + etc.
And in case your table name has special characters perhaps it should be enclosed in brackets
SET #sql = 'DELETE FROM dbo.[' + #TABLE_NAME + ']' + etc.
Since #Value is a string, you must surround it with single quotes when computing the value for #SQL. To insert a single quote into a string you have to escape it by using two single quotes, like this:
SET #SQL = 'DELETE FROM dbo.[' + #TABLE_NAME + '] WHERE [' + #COLUMN_NAME + '] = '''' + #VALUE + ''''
If #VALUE itself contains a single quote, this whole thing will break, so you need to escape that as well
SET #SQL = 'DELETE FROM dbo.[' + #TABLE_NAME + '] WHERE [' + #COLUMN_NAME + '] = '''' + REPLACE(#VALUE,'''','''''') + ''''
Also, ##ROWCOUNT will not populate from EXEC. If you want to be able to read ##ROWCOUNT, use sp_ExecuteSQL instead
EXEC sp_ExecuteSql #SQL
And finally, let me editorialize for a minute--
This sort of stored procedure is not a great idea. I know it seems pretty cool because it is flexible, and that kind of thinking is usually smart when it comes to other languages, but in the database world this approach causes problems, e.g. there are security issues (e.g. injection, and the fact that you need elevated privileges to call sp_executeSql) and there issues with precompilation/performance (because the SQL isn't known ahead of time, SQL Server will need to generate a new query plan each and every time you call this) and since the caller can supply any value for table and column name you have no idea whether this delete statement will be efficient and use indexes or if it will cause a huge performance issue because the table is large and the column is not indexed.
The proper approach is to have a series of appropriate stored procedures with strongly-typed inputs that are specific to each data use case where you need to delete based on criteria. Database engineers should not be trying to make things flexible; you should be forcing people to think through what exactly they are going to need, and implement that and only that. That is the only way to ensure people are following the rules, keeping R/I intact, efficient use of indexes, etc.
Yes, this may seem like repetitive and redundant work, but c'est la vie. There are tools available to generate the code for CRUD operations if you don't like the extra typing.
In addition to some of the information John Wu provided you have to worry about data types and ##ROWCOUNT may not be accurate if there are triggers on your tables and things..... You can get around both of those issues though by casting to nvarchar() and using OUTPUT clause with a temp table to do the COUNT().
So just for fun here is a way you can do it:
CREATE PROCEDURE dbo.[ProcName]
#TableName SYSNAME
,#ColumnName SYSNAME
,#Value NVARCHAR(MAX)
,#RecordCount INT OUTPUT
AS
BEGIN
DECLARE #SQL NVARCHAR(1000)
SET #SQL = N'IF OBJECT_ID(''tempdb..#DeletedOutput'') IS NOT NULL
BEGIN
DROP TABLE #DeletedOutput
END
CREATE TABLE #DeletedOutput (
ID INT IDENTITY(1,1)
ColumnValue NVARCHAR(MAX)
)
DELETE FROM dbo.' + QUOTENAME(#TableName) + '
OUTPUT deleted.' + QUOTENAME(#ColumnName) + ' INTO #DeletedOutput (ColumnValue)
WHERE CAST(' + QUOTENAME(#ColumnName) + ' AS NVARCHAR(MAX)) = ' + CHAR(39) + #Value + CHAR(39) + '
SELECT #RecordCountOUT = COUNT(ID) FROM #DeletedOutput
IF OBJECT_ID(''tempdb..#DeletedOutput'') IS NOT NULL
BEGIN
DROP TABLE #DeletedOutput
END'
DECLARE #ParmDefinition NVARCHAR(200) = N'#RecordCountOUT INT OUTPUT'
EXECUTE sp_executesql #SQL, #ParmDefinition, #RecordCountOUT = #RecordCount OUTPUT
END
So the use of QOUTENAME will help against the injection attack but not be perfect. And I use CHAR(39) instead of the escape sequence for a single quote on value because I find it easier when string building at that point.... By using Parameter OUTPUT from sp_executesql you can still return your count.
Keep in mind just because you can do something in SQL doesn't always mean you should.
I am trying to create a script to create/setup a group of stored procedures that will all be fairly similar.
So I am trying to loop through this code, changing the #DATABASE_NAME and #TableName when needed.
/* Start loop */
DECLARE #create_stored_procedure nvarchar(max)
SET #create_stored_procedure = N'
USE [' + #DATABASE_NAME + ']
CREATE PROCEDURE [dbo].[sproc_imp_' + #TableName + ']
AS
BEGIN
PRINT(''doing something'')
END'
EXEC sp_executesql #statement = #create_stored_procedure
/* End loop */
But I am getting errors saying
'CREATE/ALTER PROCEDURE' must be the first statement in a query batch.
or
'CREATE/ALTER PROCEDURE' does not allow specifying the database name as a prefix to the object name.
All the solutions online suggest using GO, but that won't work in dynamic SQL.
Does anyone know a possible solution for SQL Server 2005?
I wouldn't call the solution intuitive, but apparently this works. I prefer the look of this one though.
Try with spiting USe DB and create procedure. Like this
DECLARE #create_store_procedure nvarchar(max)
SET #create_store_procedure = N'
USE [' + #DATABASE_NAME + '] '
EXEC sp_executesql #statement = #create_store_procedure
SET #create_store_procedure = N'
CREATE PROCEDURE [dbo].[sproc_imp_' + #TableName + ']
AS
BEGIN
PRINT(''doing something'')
END '
EXEC sp_executesql #statement = #create_store_procedure
This is working perfectly for me
I tried Nithesh's answer and that didn't work for me it ended up creating the store procedure in the master table. Zec's answer worked. Creating a dynamic query inside my dynamic query.
DECLARE #create_store_procedure nvarchar(max)
DECLARE #use_db nvarchar(max)
SET #create_store_procedure = N'
CREATE PROCEDURE [dbo].[sproc_imp_' + #TableName + ']
AS
BEGIN
PRINT(''doing something'')
END '
SET #use_db = N'
USE [' + #DATABASE_NAME + ']
DECLARE #sub_create_store_procedure nvarchar(max)
SET #sub_create_store_procedure = ''' + REPLACE(#create_store_procedure, CHAR(39), CHAR(39) + CHAR(39)) + '''
EXEC sp_executesql #statement = #sub_create_store_procedure
'
EXEC sp_executesql #statement = #use_db
if i put something
DECLARE #Query VARCHAR(8000)
SET #Query = 'select * from subscriber
where sbs_userid = ' + cast(#UserID as varchar) + '
and SBS_Status in (select statusFlag from #tmpStatusFlag)
and SBS_SourceFlag in (select sourceFlag from #tmpSourceFlag)'
IF (#FirstName !='')
SET #Query = #Query + ' and SBS_FirstName like ''%' + #FirstName + '%'''
IF(#LastName !='')
SET #Query = #Query + ' and SBS_LastName like ''%' + #LastName + '%'''
IF(#Phone !='')
SET #Query = #Query + ' and SBS_WorkPhone like ''%' + #Phone + '%'''
IF(#EmaiAdderess !='')
SET #Query = #Query + ' and SBS_EmailAddress like ''%' + #EmaiAdderess + '%'''
IF(#City !='')
SET #Query = #Query + ' and SBS_City like ''%' + #City + '%'''
IF(#SubListId !='-1')
SET #Query = #Query + ' and SBS_SubListId like ''%' + #SubListId + '%'''
SET #Query = #Query + ' order by SBS_CreationDate desc'
EXEC (#Query)
in my stored procedure .
my question is still i get the benefits of stored procedure or is it a wrong approach
i never use this but my Team Leader used this to speed up the stored proceure . is it ok ?
EDITED
IF we use sp_executesql instead of exec then we can take the benefits of stored procedure.and is this ok with this ?
No.
You would need to use EXEC sp_executesql to get the advantages of parameterisation (plan reuse - protection from SQL injection).
These leading wild card searches are going to be expensive anyway. Have you considered Full Text Indexing?
Following the edit
If we use sp_executesql instead of exec then we can take the benefits
of stored procedure.and is this ok with this ?
Not all the benefits of stored procedures. A couple of advantages that stored procedures would still have over sp_executesql would be that you could then use ownership chaining and only need to grant exec permissions on the stored procedure rather than select on the underlying objects. Additionally having static stored procedures rather than dynamic SQL strings can make it easier to find dependant objects when refactoring the database.
However in your case you would need 64 separate procedures for each combination of presence/absence for the 6 optional parameters and this number grows exponentially as more optional parameters are added.
See Dynamic Search Conditions in T-SQL Version for SQL 2005 and Earlier for a thorough discussion of this topic.