Query works in SSMS but not in SSIS -

need guys. trying use following query data fom table. works in ssms , in ssis throws error.

select  convert(varchar(10), getdate(), 120) col1 union select  cast (customerid varchar)    tcustomer union select  cast(count(*) varchar) col1    tcustomer 

throwing error

[ole db source [1]] error: there error output column "col1" (35) on output "ole db source output" (11). column status returned was: "the value not converted because of potential loss of data.". 

what trying achieve

header line yyyy-mm-dd  --e.g. 2013-07-01 data records trailer record ---e.g. 13480 

where going wrong ?

the error see happens due data incompatibility.

in first convert(varchar(10) specify length 10

msdn says, default varchar size 30, doing cast(x varchar) equals cast(x varchar(30)). here have length of 30

and have column, length 20, , here have "potential loss of data"