count 1 vs count
There is no difference. Reason: Books on-line says " COUNT ( [ [ ALL | DISTINCT ] expression ] | * } ) ". "1" is a non-null expression: so it's the same as ... , Bottom Line. Use either COUNT(field) or COUNT(*) , and stick with it consistently, and if your database allows COUNT(tableHere) or ...
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 count 1 vs count 相關參考資料
COUNT(*) or COUNT(1) - SearchOracle - TechTarget
count(*) counts all the rows values, where count(1) only counts one row value and only return one value vs lets say the other five rows that are ... https://searchoracle.techtarge Count(*) vs Count(1) - SQL Server - Stack Overflow
There is no difference. Reason: Books on-line says " COUNT ( [ [ ALL | DISTINCT ] expression ] | * } ) ". "1" is a non-null expression: so it's the same as ... https://stackoverflow.com COUNT(*) vs. COUNT(1) vs. COUNT(pk): which is better?
Bottom Line. Use either COUNT(field) or COUNT(*) , and stick with it consistently, and if your database allows COUNT(tableHere) or ... https://stackoverflow.com count(1)、count(*)与count(列名)的执行区别 - CSDN
如果count(1)是聚索引,id,那肯定是count(1)快。但是差的很小的。 因为count(*),自动会优化指定到那一个字段。所以没必要去count(1) ... https://blog.csdn.net Select Count(*) Count(1) Count(欄位名) 的差異| Jeff ... - 點部落
在T-SQL裡有個Count()函數,使用相當的廣泛,但Select Count(*),Select Count(1),Select Count(欄位名稱),這. https://dotblogs.com.tw What's Faster? COUNT(*) or COUNT(1)? - jOOQ blog
Or was it that COUNT(1) is faster than COUNT(*)? Impossible to remember, because ... Back to COUNT(*) vs COUNT(1). Now that we know the ... https://blog.jooq.org What's the difference between COUNT(1), COUNT(*), and ...
SELECT COUNT(1) FROM people; SELECT COUNT(*) FROM people;. we're going to get a result of 3 because there are three rows in the table. https://discuss.codecademy.com 高性能MySQL——Count(1) OR Count(*)？ - 知乎
如果问一个程序员MySQL中SELECT COUNT(1)和SELECT COUNT(*)有什么区别，会有很多人给出这样的答案“SELECT COUNT(*)”最终会转化 ... https://zhuanlan.zhihu.com |