Dynamic Query Calling User Defined Function

I have the following procedure, that calls a Padding function to pad characters to a field.

Here is what the procedure looks like

Code:

CREATE PROCEDURE [dbo].[Pad_Left]

@Table VARCHAR(255),
@Column VARCHAR(255),
@PadChar CHAR(1),
@PadToLen INT

AS

DECLARE @Query Varchar(5000)

SET @Query = 'UPDATE ' + @Table + '

SET ' + @Column + ' = dbo.Function_PadLeft(' + @Column + ', ''' + @PadChar + ''', ' + @PadToLen + ')'

EXECUTE(@Query)
GO



When I run this I get the error

Server: Msg 245, Level 16, State 1, Procedure Pad_Left, Line 13
Syntax error converting the varchar value 'UPDATE Lincoln

SET baths = dbo.Function_PadLeft(baths, '0', ' to a column of data type int.

But when I just run this query, it works


Code:

CREATE PROCEDURE [dbo].[Pad_Left]

@Table VARCHAR(255),
@Column VARCHAR(255),
@PadChar CHAR(1),
@PadToLen INT

AS

UPDATE Lincoln

SET Baths = dbo.Function_PadLeft(Baths, '0', 4)

GO



Why would one work but not the other? I don't understand, as they are the same thing, just one calls the function dynamically?

I must be missing something very obvious

Thanks for any help!