子表关联同一个主表的id,子表如何查同一种类型的数据?附源数据
主表tmp_main
子表tmp_child
查询同一条主表记录,包含type=1的记录,查出main_id=1,2,3,4的记录
SELECT c.main_id,m.number FROM tmp_main m
LEFT JOIN tmp_child c ON m.id=c.main_id
WHERE user_id=222
GROUP BY c.main_id,c.type
HAVING c.type=1
如何查同一条主表记录,子表type全是2的数据呢?
要做分页查询,怎么办呢?
例如根据下面的数据源,查出main_id=5的记录
以下是表结构与数据
CREATE TABLE `tmp_main` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`number` int(11) NULL DEFAULT 0,
PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 6 CHARACTER SET = utf8mb4 COLLATE = utf8mb4_general_ci ROW_FORMAT = Dynamic;
INSERT INTO `tmp_main` VALUES (1, 10310);
INSERT INTO `tmp_main` VALUES (2, 10320);
INSERT INTO `tmp_main` VALUES (3, 10330);
INSERT INTO `tmp_main` VALUES (4, 10340);
INSERT INTO `tmp_main` VALUES (5, 10350);
CREATE TABLE `tmp_child` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`user_id` int(11) NULL DEFAULT 0,
`main_id` int(11) NULL DEFAULT 0,
`type` tinyint(1) NULL DEFAULT 1,
PRIMARY KEY (`id`) USING BTREE,
INDEX `idx_main_id`(`main_id`) USING BTREE,
INDEX `idx_user_id`(`user_id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 119 CHARACTER SET = utf8mb4 COLLATE = utf8mb4_general_ci ROW_FORMAT = Dynamic;
INSERT INTO `tmp_child` VALUES (110, 222, 1, 1);
INSERT INTO `tmp_child` VALUES (111, 222, 1, 1);
INSERT INTO `tmp_child` VALUES (112, 222, 2, 1);
INSERT INTO `tmp_child` VALUES (113, 222, 2, 2);
INSERT INTO `tmp_child` VALUES (114, 222, 3, 1);
INSERT INTO `tmp_child` VALUES (115, 222, 3, 2);
INSERT INTO `tmp_child` VALUES (116, 222, 4, 1);
INSERT INTO `tmp_child` VALUES (117, 222, 5, 2);
INSERT INTO `tmp_child` VALUES (118, 222, 5, 2);
如果是使用的 laravel 框架,参考 : 查询已存在的关联, 用 whereHas 就行了