stored procedure to remove quotes - sql

Question

I am trying to write a stored procedure that will removed leading and trailing quotes from an arbitrary table and column. I keep getting an error saying that the table name isn't declared.
Here is the SP
create table [dbo].[test] (id nvarchar(20))
insert into dbo.test values ('"07617966004766"')
go
CREATE PROCEDURE sp_stripDoubleQuotes
#tableName sysname,
#columnName sysname
AS
BEGIN
SET NOCOUNT ON;
UPDATE #tableName
SET #columnName = SUBSTRING(#columnName, 2, LEN(#columnName))
WHERE LEFT(#columnName, 1) = '"'
UPDATE #tableName
SET #columnName = SUBSTRING(#columnName, 1, LEN(#columnName)-1)
WHERE RIGHT(#columnName, 1) = '"'
END
GO
exec [dbo].[sp_stripDoubleQuotes] N'[dbo].[test]', N'[id]'
select * from test
Here is a link to a fiddle:
link to fiddle

Answer 1

CREATE PROCEDURE sp_stripDoubleQuotes
#tableName sysname,
#columnName sysname,
#SQL varchar(MAX)
AS
BEGIN
SET NOCOUNT ON;
SET #SQL =
'UPDATE ' + '[' + #tableName +']' +
'SET' + '[' + #columnName +']' +'= SUBSTRING(' +'[' + #columnName +']' +', 2, LEN(' +'[' + #columnName +']' +'))
WHERE LEFT(' + '[' + #columnName +']' +', 1) = '+'''"'''
--PRINT(#SQL)
EXEC (#SQL)
SET #SQL =
'UPDATE ' + '[' + #tableName +']' +
'SET' + '[' + #columnName +']' +'= SUBSTRING(' + '[' + #columnName +']' +', 1, LEN(' + '[' + #columnName + ']' +')-1)
WHERE RIGHT(' + '[' + #columnName +']' +', 1) = '+'''"'''
--PRINT(#SQL)
EXEC (#SQL)
END
GO
exec [dbo].[sp_stripDoubleQuotes] N'test', N'id' -- exec [dbo].[sp_stripDoubleQuotes] N'[dbo].[test]', N'[id]'
Updated 2nd: I added [] to wrap table and column incase your table and column name have whitespace in them. Thanks #Sean Lange and #Richard
Updated 3rd: As #[benjamin moskovits] (xD) mentioned, if you hard coded brackets, the correct execute command is exec [dbo].[sp_stripDoubleQuotes] N'test', N'id'. Try to add or remove brackets and print to see whether the syntax is correct before executing it.

Answer 2

CREATE PROCEDURE sp_stripDoubleQuotes
#tableName sysname,
#columnName sysname
AS
BEGIN
SET NOCOUNT ON;
declare #QuerytoExecute varchar(1000)
set #QuerytoExecute="UPDATE "+#tableName+"
SET "+#columnName+" = SUBSTRING("+#columnName+", 2, LEN("+#columnName+"))
WHERE LEFT("+#columnName+", 1) = '""'";
exec (#QuerytoExecute);
set #QuerytoExecute="
UPDATE "+#tableName+"
SET "+#columnName+" = SUBSTRING("+#columnName+", 1, LEN("+#columnName+")-1)
WHERE RIGHT("+#columnName+", 1) = '""'";
exec (#QuerytoExecute);
END
GO