which silver medalist of the swimming at the 2012 summer olympics – men's 100 metre butterfly was also the flagbearer of the south africa at the 2015 all-africa games
SELECT DISTINCT var_uri where brack_open dbr_Swimming_at_the_2012_Summer_Olympics_–_Men's_100_metre_butterfly dbo_silverMedalist var_uri sep_dot dbr_South_Africa_at_the_2015_All-Africa_Games dbp_flagbearer var_uri brack_close