php与sql连接的小应用

我想让导航区的分类名可以跟随我的点击展现在主体区上方相应的标题

建议阅读：

https://blog.csdn.net/Fighting_hawk/article/details/122933980?ops_request_misc=%257B%2522request%255Fid%2522%253A%2522167212195116800222829131%2522%252C%2522scm%2522%253A%252220140713.130102334.pc%255Fall.%2522%257D&request_id=167212195116800222829131&biz_id=0&utm_medium=distribute.pc_search_result.none-task-blog-2~all~first_rank_ecpm_v1~pc_rank_34-1-122933980-null-null.142^v68^pc_new_rank,201^v4^add_ask,213^v2^t3_esquery_v3&utm_term=php%E4%B8%8Esql%E8%BF%9E%E6%8E%A5%E7%9A%84%E5%B0%8F%E5%BA%94%E7%94%A8&spm=1018.2226.3001.4187