https://blog.youkuaiyun.com/Java_dacainiaozh-cnhttps://blog.youkuaiyun.com/https://blog.youkuaiyun.com/Java_dacainiao/article/details/131465305https://blog.youkuaiyun.com/Java_dacainiao/article/details/131465305Java_dacainiaoThu, 29 Jun 2023 23:11:00 +0800https://blog.youkuaiyun.com/Java_dacainiao/article/details/130170032https://blog.youkuaiyun.com/Java_dacainiao/article/details/130170032Java_dacainiaoSat, 15 Apr 2023 14:55:43 +0800 mysql> insert into person values(1 ,'荆' ,0 ,18,'好可爱的’ ，19.99);​ 新建表：create table 表名字 (字段1 数据类型,字段2 数据类型,...);> #3.在指定的字段的后面添加一个字段 name的字段的后面添加一个字段。redis mongodb memoryche 等 键值对。]]>https://blog.youkuaiyun.com/Java_dacainiao/article/details/130169846https://blog.youkuaiyun.com/Java_dacainiao/article/details/130169846Java_dacainiaoSat, 15 Apr 2023 14:36:36 +0800https://blog.youkuaiyun.com/Java_dacainiao/article/details/130169737https://blog.youkuaiyun.com/Java_dacainiao/article/details/130169737Java_dacainiaoSat, 15 Apr 2023 14:30:40 +0800https://blog.youkuaiyun.com/Java_dacainiao/article/details/130169376https://blog.youkuaiyun.com/Java_dacainiao/article/details/130169376Java_dacainiaoSat, 15 Apr 2023 14:26:00 +0800https://blog.youkuaiyun.com/Java_dacainiao/article/details/130167798https://blog.youkuaiyun.com/Java_dacainiao/article/details/130167798Java_dacainiaoSat, 15 Apr 2023 11:47:49 +0800https://blog.youkuaiyun.com/Java_dacainiao/article/details/130167659https://blog.youkuaiyun.com/Java_dacainiao/article/details/130167659Java_dacainiaoSat, 15 Apr 2023 11:29:26 +0800https://blog.youkuaiyun.com/Java_dacainiao/article/details/129898270https://blog.youkuaiyun.com/Java_dacainiao/article/details/129898270Java_dacainiaoSat, 01 Apr 2023 15:55:38 +0800https://blog.youkuaiyun.com/Java_dacainiao/article/details/129865686https://blog.youkuaiyun.com/Java_dacainiao/article/details/129865686Java_dacainiaoThu, 30 Mar 2023 20:13:19 +0800https://blog.youkuaiyun.com/Java_dacainiao/article/details/129803087https://blog.youkuaiyun.com/Java_dacainiao/article/details/129803087Java_dacainiaoMon, 27 Mar 2023 21:23:05 +0800> entrySet () 将键值对 的map的实体存到set集合中。V put (K key , V value) 当键没有的话，就是添加，没有的话，就是覆盖。通过键删除指定的值，返回值是被删除的值。Collection valles() 获取所有集合中的值。Set keySet() 获取所有的键存到set集合中。查看集合中的元素的个数。将指定的值与该映射中的指定键相关联（可选操作）是一个双边队列 存的是键值对的数据。]]>https://blog.youkuaiyun.com/Java_dacainiao/article/details/129767134https://blog.youkuaiyun.com/Java_dacainiao/article/details/129767134Java_dacainiaoMon, 27 Mar 2023 11:07:08 +0800 返回值的类型 方法的名字（参数）{无意义的占位符： 可以是任意的字符 但是都是大写 开发中一般是 T（Type） E(Element)？（未知）无参无返回值 、、 没必要使用泛型的有参无返回值 、、 可以使用无参有返回值 、、没必要使用泛型的有参有返回值 、、 写起来有局限性//有参的才有点用途。]]>https://blog.youkuaiyun.com/Java_dacainiao/article/details/129766755https://blog.youkuaiyun.com/Java_dacainiao/article/details/129766755Java_dacainiaoSat, 25 Mar 2023 14:30:55 +0800https://blog.youkuaiyun.com/Java_dacainiao/article/details/129766504https://blog.youkuaiyun.com/Java_dacainiao/article/details/129766504Java_dacainiaoSat, 25 Mar 2023 14:15:31 +0800https://blog.youkuaiyun.com/Java_dacainiao/article/details/129764085https://blog.youkuaiyun.com/Java_dacainiao/article/details/129764085Java_dacainiaoSat, 25 Mar 2023 11:40:13 +0800