MySQL中|MySQL中 and or 查询的优先级分析 MySQL中andor查询的优先级分析

这个可能是容易被忽略的问题，首选我们要清楚：
MySQL中，AND的执行优先级高于OR。也就是说，在没有小括号()的限制下，总是优先执行AND语句，再执行OR语句。
比如：

select * from table where条件1 AND 条件2 OR 条件3等价于select * from table where( 条件1 AND 条件2 )OR 条件3select * from table where条件1 AND条件2 OR 条件3 AND 条件4等价于select * from table where (条件1 AND条件2) OR (条件3 AND 条件4)

来点事例深入理解下：
测试表数据：

SET NAMES utf8mb4; SET FOREIGN_KEY_CHECKS = 0; -- ------------------------------ Table structure for book-- ----------------------------DROP TABLE IF EXISTS `book`; CREATE TABLE `book` ( `id` int(10) UNSIGNED NOT NULL AUTO_INCREMENT, `name` varchar(25) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DEFAULT NULL, `author` varchar(25) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DEFAULT NULL, `price` decimal(10, 2) DEFAULT NULL, PRIMARY KEY (`id`) USING BTREE) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_0900_ai_ci ROW_FORMAT = Dynamic; -- ------------------------------ Records of book-- ----------------------------INSERT INTO `book` VALUES (1, 'PHP', 'mate', 21.00); INSERT INTO `book` VALUES (2, 'JAVA', 'kaven', 23.00); INSERT INTO `book` VALUES (3, 'JAVA高级', 'loose', 45.00); INSERT INTO `book` VALUES (4, 'GO', 'jim', 46.00); INSERT INTO `book` VALUES (5, 'GO设计', 'json', 76.00); INSERT INTO `book` VALUES (6, 'PHP高级编程', 'bate', 67.00); INSERT INTO `book` VALUES (7, 'Python', 'jim', 66.00); INSERT INTO `book` VALUES (8, 'Python设计', 'mali', 54.00); INSERT INTO `book` VALUES (9, 'GO编程', 'kaven', 86.00); INSERT INTO `book` VALUES (11, 'Python3', 'jim', 55.00); SET FOREIGN_KEY_CHECKS = 1;