关于[MySQL COUNT() – Get the Number of Rows to be Returned by a Query]的摘要:
MySQLincludes a COUNT() function, which allows you to find out how many rows would be returned from a query. This function is part of the SQLstandard, and it can be used with most relational database ...
原文地址: https://database.guide/mysql-count-get-the-number-of-rows-to-be-returned-by-a-query/