我可以一起使用COUNT（）和DISTINCT吗？

Question

我想计算一个mysql表中的行数，而不是包含重复的条目，

我可以将distinct与count()一起使用吗？

Answer 1

不确定

SELECT COUNT(DISTINCT column) FROM table;

Answer 2

您需要的是以下内容：

SELECT field_type_name, count(*) FROM fields GROUP BY field_type_name;

这会给你这样的东西：

image   14
string  75
text     9

Answer 3

 SELECT COUNT(DISTINCT field) from Table

See this

Answer 4

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