一个员工表,有三列
name,category,salary
John, contract, 2000
Joe, permanent, 2300
Annie,contract, 2050
Jerry, contract, 2550
Tom, permanent, 2340
现在查询表,按照工资从高到低排列,正式工排前面,合同工排后面,如上表,应该输出这样:
Tom,permanent, 2340
Joe, permanent,2300
Jerry,contract, 2550
Annie,contract, 2050
John,contract, 2000
SQL语句如何写啊?