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mysql字段存储emoji表情问题在进行包含表情符号插入数据时报错;Caused by: java.sql.SQLException: Incorrect string value: '\xF0\x9F\x98\x81\xF0\x9F...' for column 'content' at row 1考虑是因为编码问题查询数据库编码：show variables like 'char%'修改：set character_set_server= 'utf8mb4'重启服务。..

高并发下的秒杀功能设计(方案一)表结构CREATE TABLE `order_info` ( `order_id` bigint NOT NULL COMMENT '订单id', `order_type` tinyint NOT NULL DEFAULT '1' COMMENT '订单类型（1-普通订单，2-秒杀订单）', `goods_id` int NOT NULL COMMENT '商品id', `nums` int NOT NULL COMMENT '商品数量', `pric

Error Code: 1175. You are using safe update mode and you tried to update a table without a WHERE that uses a KEY column. To disable safe mode, toggle the option in Preferences -> SQL Editor and reconnect.MYSQL取消安全模式SET SQL_SAFE_UPDATES=0;...

mysql计算环比增长率需求：统计所选时间之内的月度的环比增长率sql:SELECT afterData.com_code, AVG((afterData.sumPower - beforeData.sumPower) / 1) / (COUNT(1)) `avgGrowthRate`FROM (SELECT com_code, DATE_FORMAT(measure_date, '%Y%m') `month`,

mysql按照指定的天数对日期字段进行分组解决思想其实就是算出一个日期天数除天数得到的商进行分组-- 28天月用电量均值SELECT com_code, avgPower, monthFROM (SELECT cons.com_code, AVG(acture_day_amount) avgPower, (DATEDIFF('2020-08-31', measure_date) DIV 28) AS `month`