DECLARE
    @cmd nvarchar(MAX) = N''

SELECT @cmd =
    N'EXEC master.sys.xp_cmdshell ''bcp "SELECT * FROM StackOverflow2010.dbo.Posts;' +
    N'" queryout "' +
    N'C:\temp\dbo_Posts.txt' +
    N'" -w -T '''
GO

EXEC sys.sp_executesql
    @cmd

DECLARE
    @cmd nvarchar(MAX) = N''

SELECT @cmd =
    N'EXEC master.sys.xp_cmdshell ''bcp Erik.dbo.Posts in C:\temp\dbo_Posts.txt' +
    N' -w -U sekret -P sekret! -S tcp:sekret.database.windows.net'''

EXEC sys.sp_executesql
    @cmd
GO