SQL> select * from a;

        ID NAME
---------- ------------------------
         1 abc
         2 bbb
         3 bbb
         3

一直以为下面的结果应该是一至的！

SQL> select count(*) from a;

COUNT(*)
----------
4

SQL> select count(name) from a;

COUNT(NAME)
-----------
3

SQL> select count(1) from a;

COUNT(1)
----------
4

SQL> select count(distinct name) from a;

COUNT(DISTINCTNAME)
-------------------
2

ITPub博客

更正自己对count()函数的误解