问题描述我想把a表的chapterid字段改为b表的id字段, 条件是courseid相同 可是下面的sql语句无效, 求大神解答..相关代码 UPDATE cmf_course_lesson a, cmf_course_chapter b SET a.chapterid = b.id WHERE a.courseid = b.courseid; a表的表结构b表的表结构
UPDATE cmf_course_lesson a, cmf_course_chapter bJOIN cmf_course_lesson ON a.courseid = b.courseidSET a.chapterid = b.courseid
UPDATE cmf_course_lesson a left join cmf_course_chapter b ON a.courseid = b.courseid SET a.chapterid = b.courseid where b.courseid > 0;
where条件加上主键就好了 where ... and A.id > 0
MySql运行在safe-updates模式下,导致非主键条件下无法执行update或者delete命令