MySQL的binlog日志是用来记录数据库的更改操作，如果开启binlog日志，可以记录数据库更改操作，有助于恢复数据库，提高数据库的安全性。
要开启MySQL的binlog日志，需要在MySQL的配置文件m
2023-06-21 08:53
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SELECT stu_num, stu_name FROM student WHERE stu_num IN (SELECT stu_num FROM student WHERE stu_num != 01 IN
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SELECT stu_id,name FROM student
WHERE stu_id NOT IN
(SELECT stu_id FROM score
WHERE course IN
(SELECT cour
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：
SELECT student_id, name FROM Student WHERE student_id IN (SELECT student_id FROM Course WHERE teacher_nam
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语句用于从两个或多个表中返回所有匹配指定条件的记录。
LEFT JOIN 语法：
SELECT column_name(s)
FROM table1
LEFT JOIN table2
ON table1.colu
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全连接指的是在两张或多张表中，返回所有符合两个表的记录，包括左表和右表的记录，即使右表或者左表某个字段没有匹配的记录。它与JOIN的区别在于：JOIN只返回两张表中存在匹配记录的结果，而FULL JOIN则返回所有
2023-06-17 09:37
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SELECT student_id, student_name FROM student
WHERE student_id NOT IN (SELECT student_id FROM course WHERE
2023-06-16 08:38
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