Q:

Merge multiple rows in variable type varchar

I Have temp table name @Definition which have 2 columns one for id and Field value I Have to take all rows in the field value as string in @P_Output 
declare @P_Output varchar(500);
set @P_Output=(select case when (ISNumeric(FieldValue))=1 then convert(varchar(100),FieldValue) else FieldValue END from @Definition)

This give my an error :

Conversion failed when converting the varchar value 'You get an Error in line ' to data type int.

my table look like the picture 
and the required output 
needed to be :
P_Output=create table (id int not null identity(1,1).......

A:

You should be able to customize this example:
set nocount on
Declare @Definition table (ID int, FieldValue varchar(100))
DECLARE @P_Output varchar(max)

insert into @Definition (ID,FieldValue) values(1,'CREATE TABLE dbo.test')
insert into @Definition (ID,FieldValue) values(2,'(')
insert into @Definition (ID,FieldValue) values(3,'col1 int')
insert into @Definition (ID,FieldValue) values(4,')')

SELECT @P_Output = isnull(@P_Output + '', '') + FieldValue
from @Definition order by ID

print @P_Output

