dynamic sql in stored procedure with column name as input parameter - sql-server

I have this stored procedure that accept a comlumn name as inptu parameter. The SELECT statement will select a column according to input parameter
create procedure getColumn (#whichColumn varchar)
as
begin
declare #sql nvarchar(max)
set #sql = 'SELECT [' + #whichColumn + ']'
+ ' FROM myTable'
+ ' where ['+ #whichColumn + '] is not null'
+ ' and [' + #whichColumn + '] != '''' ' ;
exec sp_executesql #sql
end
When I execute this stored procedure,
exec getColumn 'Apple';
the error says "Invalid column name 'A' " .
I cannot see why it only gets the first character of the input

Check out your parameter declaration:
#whichColumn varchar
From MSDN:
When n is not specified in a data definition or variable declaration
statement, the default length is 1.
So that's a single-letter varchar. Try to specify a size:
#whichColumn varchar(50)
Or even better, use the system-defined type for object names:
#whichColumn sysname

create procedure getColumn (#whichColumn nvarchar(128)) --<-- Maximum column name lenght
as
begin
declare #sql nvarchar(max);
set #sql = N'SELECT ' + QUOTENAME(#whichColumn)+ N' FROM myTable'
+ N' where '+ QUOTENAME(#whichColumn) + N' is not null'
+ N' and ' + QUOTENAME(#whichColumn) + N' != '''' ' ;
exec sp_executesql #sql
end
On a side note Using square brackets in you concatinating string isnt the same as using QUOTENAME function.

Change this line
create procedure getClumn (#whichColumn varchar)
to
create procedure getClumn (#whichColumn varchar(max))
because if you are not assign size of varchar at that time it consider only one character so it get only one character A and generate error.

Related

Error while using variable declaration Incorrect syntax near '+#TABLENAME1+'

DECLARE #SQLSTRING VARCHAR(1500);
DECLARE #TABLENAME1 VARCHAR(30)='NOV19_COMBINE'
---------------TABLE CREATION WITH FILE NAME--------------------------
SET #SQLSTRING = 'SELECT
CONVERT(VARCHAR('+ cast((select max(len(EMAIL)) from '+#TABLENAME1+' ) as VARCHAR(50))+'), EMAIL ) AS EMAIL,
IDENTITY (INT,1,1) AS RECORDID
INTO FOI_'+#TABLENAME1+'_CONV
FROM '+#TABLENAME1+' A'
PRINT #SQLSTRING
Error:
Msg 102, Level 15, State 1, Line 8
Incorrect syntax near '+#TABLENAME1+'.
You have an issue here:
CONVERT(VARCHAR('+ cast((select max(len(EMAIL)) from ' + #TABLENAME1 + ' ) as VARCHAR(50))+')
where you are trying to select from a table defined in #TABLENAME1. That also needs to be part of your dynamic SQL.
However you have another issue with your convert(varchar( code in that you cannot use a variable as as the length to varchar(). I suggest using varchar(max) because that only uses the storage required.
I have also made your dynamic SQL safe from injection with the use of QUOTENAME which I recommend you use in future.
Fixed version:
DECLARE #SQLSTRING VARCHAR(1500);
DECLARE #TABLENAME1 VARCHAR(30) = 'NOV19_COMBINE'
---------------TABLE CREATION WITH FILE NAME--------------------------
SET #SQLSTRING = 'SELECT CONVERT(VARCHAR(max), EMAIL) AS EMAIL, IDENTITY (INT,1,1) AS RECORDID INTO '
+ QUOTENAME('FOI_' + #TABLENAME1 + '_CONV') + ' FROM '
+ QUOTENAME(#TABLENAME1) + ' A'
PRINT #SQLSTRING
There is no reason I can think of to do it this way, but as an academic exercise, if one really needed the exact length of the EMAIL column then one would use the following query:
declare #SQLSTRING nvarchar(max), #TABLENAME1 VARCHAR(30) = 'NOV19_COMBINE', #EMAILLENGTH int
SET #SQLSTRING = 'SELECT #Length = max(len(EMAIL)) from ' + QUOTENAME(#TABLENAME1)
EXECUTE sp_executesql #SQLSTRING, N'#Length int OUTPUT', #Length = #EMAILLENGTH OUTPUT
SET #SQLSTRING = 'SELECT CONVERT(VARCHAR(' + convert(varchar(4),#EMAILLENGTH) + '), EMAIL) AS EMAIL'
+ ', IDENTITY (INT,1,1) AS RECORDID'
+ ' INTO ' + QUOTENAME('FOI_' + #TABLENAME1 + '_CONV')
+ ' FROM ' + QUOTENAME(#TABLENAME1) + ' A'
PRINT #SQLSTRING
This requires 2 sections of dynamic SQL, the first to find the length of the EMAIL column, which is then used to built the dynamic SQL for the actual query.

SQL Server stored procedure error: "Error Message: Must declare the scalar variable" referencing a variable with sp_executesql but not without

When I want to add datetime column to entire table I can write a stored procedure which takes a date as input and then stores it into the table - like so:
ALTER PROCEDURE [dbo].[set_datettime]
(#importDate VARCHAR(100))
AS
BEGIN
UPDATE [dbo].[table1]
SET uploadDate = #importDate
END
But when I want to make the table dynamic I need to use sp_executesql. So my thought is I can do this:
ALTER PROCEDURE [dbo].[set_datettime]
(#tableName VARCHAR(100), #importDate VARCHAR(100))
AS
BEGIN
DECLARE #Sql NVARCHAR(MAX);
SET #Sql = 'UPDATE dbo.' + quotename(#tableName) + ' SET uploadDate = #importDate';
EXECUTE sp_executesql #Sql
END
but now I get an error:
Error Message: Must declare the scalar variable #importDate
Despite clearly declaring the variable. Even if I try to explicitly declare the variable again I get the error that I cant declare duplicate variables.
Other thing which I tried was to do:
SET #Sql = 'UPDATE dbo.' + quotename(#tableName) + ' SET uploadDate = ' + #importDate;
But this throws an error
Invalid column name 10-10-2019
Lastly I was able to accomplish the task (somewhat) by changing to
SET #Sql = 'UPDATE dbo.' + quotename(#tableName) + ' SET uploadDate = GETDATE()';
But in this solution I define the date in the stored procedure and doesn't take it as input, which is not ideal.
How can I have dynamic table definition while still keeping the date input variable dynamic also?
You need to parametrise your dynamic statement. I'm typing on my phone right now, so I apologise for any typographical errors:
EXEC sp_executesql #SQL, N'#importdate date', #importdate;
Never inject parameters in your dynamic statements. It creates huge security flaws in your SQL, called SQL Injection.
Edit: not on my phone now, so can write out the complete SP:
ALTER PROCEDURE [dbo].[set_datettime]
(#tableName sysname, #importDate date)
AS
BEGIN
DECLARE #Sql NVARCHAR(MAX);
SET #Sql = 'UPDATE dbo.' + quotename(#tableName) + ' SET uploadDate = #importDate;';
EXECUTE sp_executesql #Sql, N'#importDate date', #importDate;
END;
Test it first:
declare #tableName varchar(100) = 'sometable'
, #importDate varchar(100) = '10-10-2019'
DECLARE #Sql NVARCHAR(MAX);
SET #Sql = 'UPDATE dbo.' + quotename(#tableName) + ' SET uploadDate = ' + #importDate
select #Sql
This give you an incorrect statement:
UPDATE dbo.[sometable] SET uploadDate = 10-10-2019
Try this:
SET #Sql = 'UPDATE dbo.' + quotename(#tableName) + ' SET uploadDate = ' + '''' + #importDate + ''''
Which gives you
UPDATE dbo.[sometable] SET uploadDate = '10-10-2019'

Using a temporary table on SRSS report

I have a stored procedure which works without a problem at the sql server side. However, when I feed a SRSS report with this stored procedure, I am having an error such as; Invalid object name '##tempTable'.
Here is my stored procedure;
ALTER PROCEDURE [dbo].[Link_SP_Inventory]
-- Add the parameters for the stored procedure here
#StoreId int,
#StartDate date,
#EndDate date
AS
BEGIN
DECLARE #QUERY nvarchar(MAX);
SET #QUERY = N'SELECT * INTO ##tempTable ' +
N'FROM OPENQUERY("172.11.111.11", N''EXEC [DB].dbo.SP_inventory ' + CONVERT(varchar(10),#StoreId) + ',' + '''' + QUOTENAME(CONVERT(varchar,#StartDate,112),'''') + '''' + ',' + '''' + QUOTENAME(CONVERT(varchar,#EndDate,112) + '''','''') + ')';
EXEC sp_executesql #QUERY;
SET NOCOUNT ON;
SELECT * FROM ##tempTable
drop table ##tempTable
END
GO
How can I solve this issue? Thanks.
A Table referenced in a Dynamic statement can only be referenced inside that dynamic statement. Take this simple query:
EXEC sp_executesql N'SELECT 1 AS I INTO #temp;';
SELECT *
FROM #temp;
Notice the statement fails with:
Msg 208, Level 16, State 0, Line 3
Invalid object name '#temp'.
It seems, however, you don't need to temporary table, and this will work fine:
ALTER PROCEDURE [dbo].[Link_SP_Inventory]
-- Add the parameters for the stored procedure here
#StoreId int,
#StartDate date,
#EndDate date
AS
BEGIN
DECLARE #QUERY nvarchar(MAX);
SET #QUERY = N'SELECT * ' +
N'FROM OPENQUERY("172.11.111.11", N''EXEC [DB].dbo.SP_inventory ' + CONVERT(varchar(10),#StoreId) + ',' + '''' + QUOTENAME(CONVERT(varchar(8),#StartDate,112),'''') + '''' + ',' + '''' + QUOTENAME(CONVERT(varchar(8),#EndDate,112) + '''','''') + ')';
EXEC sp_executesql #QUERY;
END;
Try doing this
ALTER PROCEDURE [dbo].[Link_SP_Inventory]
-- Add the parameters for the stored procedure here
#StoreId int,
#StartDate date,
#EndDate date
AS
BEGIN
DECLARE #QUERY nvarchar(MAX);
SET #QUERY = N'SELECT * INTO ##temp_global ' +
N'FROM OPENQUERY("172.11.111.11", N''EXEC [DB].dbo.SP_inventory ' + CONVERT(varchar(10),#StoreId) + ',' + '''' + QUOTENAME(CONVERT(varchar,#StartDate,112),'''') '''' + ',' + '''' + QUOTENAME(CONVERT(varchar,#EndDate,112) + '''','''') + ')';
EXECUTE (#QUERY)
SELECT * FROM ##temp_global
DROP TABLE ##temp_global
END
I think I had this once and I had to create the temp table initially with the column names specified and then insert into it, so that your dataset would be able to pick up the column names. So something like this may work:
ALTER PROCEDURE [dbo].[Link_SP_Inventory]
-- Add the parameters for the stored procedure here
#StoreId int,
#StartDate date,
#EndDate date
AS
BEGIN
DECLARE #QUERY nvarchar(MAX);
CREATE TABLE ##tempTable ([ColumnOne] VARCHAR(10), [ColumnTwo] DATETIME) --Add required columns here
SET #QUERY = N'SELECT * FROM OPENQUERY("172.11.111.11", N''EXEC [DB].dbo.SP_inventory ' + CONVERT(varchar(10),#StoreId) + ',' + '''' + QUOTENAME(CONVERT(varchar,#StartDate,112),'''') + '''' + ',' + '''' + QUOTENAME(CONVERT(varchar,#EndDate,112) + '''','''') + ')';
INSERT INTO ##tempTable ([ColumnOne],[ColumnTwo])
EXEC (#QUERY);
SET NOCOUNT ON;
SELECT * FROM ##tempTable
DROP TABLE ##tempTable
END
GO

SQL Server procedure with parameters for table name, field name, and ID of the record

I am trying this in SQL Server and it throws an error:
ALTER PROCEDURE [dbo].[GET_TEXT_DETAIL]
#id UNIQUEIDENTIFIER,
#table VARCHAR(255),
#field VARCHAR(MAX)
AS
BEGIN
SET NOCOUNT ON;
DECLARE #sql VARCHAR(200)
SET #sql = 'select ' + QUOTENAME(#field) + ' from ' + QUOTENAME(#table) + ' where ID = ' + QUOTENAME(#id)
EXEC (#sql)
END
I get this error:
Msg 207, Level 16, State 1, Line 1
Invalid column name 'CFC2776A-6EE1-E511-A172-005056A218B0'.
Is there any way to do this so I don't have to make a bunch or procedures to pull text from a bunch of different tables?
QUOTENAME has optional second parameter quote char, so you were close and this could be solved by:
... QUOTENAME(#id, '''')
but the most proper way for this case is passing the parameter:
set #cmd = '
SELECT t.' + QUOTENAME(#field) + '
FROM ' + QUOTENAME(#table) + ' t
WHERE t.ID = #ID'
exec sp_executesql #cmd, N'#ID uniqueidentifier', #ID
And server will be able to reuse plan as #srutzsky mentioned. Because #ID is no longer part of a query text and #cmd text remains the same for different #ID (and same #table+#field).
ALTER PROCEDURE [dbo].[GET_TEXT_DETAIL]
(
#id UNIQUEIDENTIFIER,
#table SYSNAME,
#field SYSNAME
)
AS
BEGIN
SET NOCOUNT ON;
DECLARE #SQL NVARCHAR(MAX)
SET #SQL = '
SELECT ' + QUOTENAME(#field) + '
FROM ' + QUOTENAME(#table) + '
WHERE ID = ''' + CAST(#id AS VARCHAR(36)) + ''''
--PRINT #SQL
EXEC sys.sp_executesql #SQL
END

use table name as parameter in sql function

I want create function, which use table name as parameter. As I search I need use dynamic sql. I try such code:
CREATE FUNCTION get_column_id
(
#TableName VARCHAR(30),
#ColumnName VARCHAR(30),
)
RETURNS int
AS
BEGIN
IF EXISTS
(
DECLARE #SQL VARCHAR(50)
SET #sql = 'SELECT' + #ColumnName + 'FROM' + #TableName + 'WHERE #ColumnName = #ColumnNameValue';
EXEC(#sql)
)
BEGIN
But get errors. Is where any way to procceed this?
I try use dynamic sql in such way
DECLARE #SQL VARCHAR(50)
SET #SQL = 'SELECT' + #ColumnName + 'FROM' + #Table + 'WHERE #ColumnName = #ColumnNameValue'
EXEC(#SQL)
DECLARE #TableName table (Name VARCHAR(30))
INSERT INTO #TableName VALUES (#SQL)
IF EXISTS
(SELECT Name FROM #TableName WHERE Name = #ColumnNameValue)
But get Invalid use of a side-effecting operator 'EXECUTE STRING' within a function.
Does anyone knows how bypass this constraint?
The error is the concatenation of string which lacks space in between,
SET #sql = 'SELECT ' + #ColumnName + ' FROM ' + #TableName + ' WHERE ' + #ColumnName + ' = ' + #ColumnNameValue;
-- ^ SPACE HERE ^ ^ ^ and here
if for instance the data type of the column is string, you need to wrap the value with single quotes,
SET #sql = 'SELECT ' + #ColumnName + ' FROM ' + #TableName + ' WHERE ' + #ColumnName + ' = ''' + #ColumnNameValue + '''';
UPDATE 1
You also need to declare the parameter #ColumnNameValue, eg
CREATE FUNCTION get_column_id
(
#TableName VARCHAR(30),
#ColumnName VARCHAR(30),
#ColumnNameValue VARCHAR(30)
)
A UDF (user defined function) in Sql Server must be deterministic. Beside your syntax errors you won't be able to accomplish your task.
if you check this article on MSDN:
http://msdn.microsoft.com/en-us/library/ms178091.aspx
You can see the citation below:
Deterministic functions always return the same result any time they are called
with a specific set of input values and given the same state of the database.
Nondeterministic functions may return different results each time they are
called with a specific set of input values even if the database state that
they access remains the same.

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