${if(len(sex) == 0,"","and vd.id in (select id from view_dcwj where data_key='xb' and data_value in ('" + sex + "')"))}
${if(len(sex) == 0,"","and vd.id in (select id from view_dcwj where data_key='xb' and data_value in ('" + sex + "')")}
最后多了个个括号
正确写法
${if(len(sex)==0,"" ,"and vd.id in ( select id from view_dcwj where
data_key='xb' and data_value in ('"+sex+"') )") }