pes2008怎样select role&change position?

pes2008怎样select role&change position? SELECT piease.select select()是什么? select your Select your please select Please select select forever select skin string strsql = select * from tb_users where Role='+loginrole+'and;为什么要加那么多引号,其中的双引号和单引号起什么作用,还有为什么要用+号,and是干什么用的, role of role是什么意思 alleged role Supporting role select count(*) from table1 select count(*) from table2 select count(*) from table3我从table1 table2 table3 中 找数据的条数怎样一下子用一条sql语句 算出TABLE1 TABLE2 TABLE3 记录的总和? select t.*和select *有什么不同 select a house,andthen selectupgrade.