MYSQL如何截取字符串‘AAA-ZZZ-BBB-CCC’ 中的‘ZZZ’
substring_index(substring_index(substring_index(字段名,"-",2),"-",-1),"-",1)
right(left("AAA-ZZZ-BBB-CCC",7),3)
substring("AAA-ZZZ-BBB-CCC",5,3)