一、说明
mysqlslap是MySQL自带了一款数据库压力测试工具。可以用来对自己的数据库的并发能力进行模拟测试。更多详细说明，请参加官方文档。
这里分享一个用于检测数据库的并发能力的MySQL语句。
安装MySQL数据库后，即可使用。
如果不能用的话，请把MySQL安装目录下的bin目录加入到环境变量。
或者在MySQL安装目录下的bin目录运行命令行也是可以的
mysqlslap -hlocalhost -uroot -proot -P3306 --concurrency=2500 --iterations=1 --auto-generate-sql --auto-generate-sql-load-type=mixed --auto-generate-sql-add-autoincrement --engine=innodb --number-of-queries=5000
-h -u, -p, -P 分别是主机地址，用户名，密码和端口。
--concurrency=2500 表示2500个并发。
--number-of-queries=5000 表示总共执行5000次的查询，平均每个并发执行2次查询。
二、实例
D:PHPCUSTOMphpcustomservermysql-8.0.16-winx64-webin>mysqlslap -hlocalhost -uroot -proot -P3306 --concurrency=2500 --iterations=1 --auto-generate-sql --auto-generate-sql-load-type=mixed --auto-generate-sql-add-autoincrement --engine=innodb --number-of-queries=5000
mysqlslap: [Warning] Using a password on the command line interface can be insecure.
mysqlslap: Error when connecting to server: 1040 Too many connections
mysqlslap: Error when connecting to server: 1040 Too many connections
...
mysqlslap: Error when connecting to server: 2003 Can't connect to MySQL server on 'localhost' (10061)
mysqlslap: Error when connecting to server: 1040 Too many connections
mysqlslap: Error when connecting to server: 2003 Can't connect to MySQL server on 'localhost' (10061)
mysqlslap: Error when connecting to server: 1040 Too many connections
mysqlslap: Error when connecting to server: 1040 Too many connections
mysqlslap: Error when connecting to server: 1040 Too many connections
mysqlslap: Error when connecting to server: 2003 Can't connect to MySQL server on 'localhost' (10061)
...
mysqlslap: Error when connecting to server: 1040 Too many connections
Benchmark
Running for engine innodb
Average number of seconds to run all queries: 22.234 seconds
Minimum number of seconds to run all queries: 22.234 seconds
Maximum number of seconds to run all queries: 22.234 seconds
Number of clients running queries: 2500
Average number of queries per client: 2
这个时候，数据库已经处理不了这么多的并发访问了。测试中，可以适当修改那两个数的参数，就可以大致了解到你的数据的能力了。