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  • mysql INNER/LEFT/RIGHT JOIN区别

     1、创建table

    DROP TABLE IF EXISTS `tab_id_index`;
    CREATE TABLE `tab_id_index` (
      `id` int(11) NOT NULL DEFAULT '0',
      `name` varchar(10) DEFAULT NULL,
      `age` int(11) DEFAULT NULL,
      PRIMARY KEY (`id`)
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
    
    -- ----------------------------
    -- Records of tab_id_index
    -- ----------------------------
    INSERT INTO `tab_id_index` VALUES ('1', '3', '12');
    INSERT INTO `tab_id_index` VALUES ('2', '3', '12');
    INSERT INTO `tab_id_index` VALUES ('3', '3', '12');
    INSERT INTO `tab_id_index` VALUES ('5', '4', '14');
    DROP TABLE IF EXISTS `tab_no_index`;
    CREATE TABLE `tab_no_index` (
      `id` int(11) NOT NULL DEFAULT '0',
      `name` varchar(10) DEFAULT NULL,
      `age` int(11) DEFAULT NULL
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
    
    -- ----------------------------
    -- Records of tab_no_index
    -- ----------------------------
    INSERT INTO `tab_no_index` VALUES ('1', '1', '12');
    INSERT INTO `tab_no_index` VALUES ('2', '1', '12');
    INSERT INTO `tab_no_index` VALUES ('3', '3', '12');
    INSERT INTO `tab_no_index` VALUES ('4', '6', '14');

    2、sql查询

    select * from tab_id_index a,tab_no_index b where a.id = b.id;

    同:

    select * from tab_id_index a INNER JOIN tab_no_index b ON a.id = b.id;


    select * from tab_id_index a LEFT JOIN tab_no_index b ON a.id = b.id;

    同:

    select * from tab_id_index a LEFT OUTER JOIN tab_no_index b ON a.id = b.id;


    select * from tab_id_index a RIGHT JOIN tab_no_index b ON a.id = b.id;

    同:

    select * from tab_id_index a RIGHT OUTER JOIN tab_no_index b ON a.id = b.id;

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  • 原文地址:https://www.cnblogs.com/bestzhang/p/10283660.html
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