字段里共包含5种值,“a”,“b”,"c","d","e",请问怎样统计这列字段每种值的记录数?
较为简便的写法是什么?有现成的函数吗?
如表 T 字段 f1,共有6条记录,
a
a
b
c
d
e
希望获得结果 count_a, count_b, count_c, count_d, count_e
-------------------------------------------------
2 1 1 1 1