如何在mysql中连接三个或更多表
我有三个表,我想从中检索值,我使用下面的查询,这给了我错误,有人能告诉我出了什么问题吗如何在mysql中连接三个或更多表,mysql,Mysql,我有三个表,我想从中检索值,我使用下面的查询,这给了我错误,有人能告诉我出了什么问题吗 SELECT a.VISITOR_TEXT,a.COMPANY_TEXT,a.CONTACT,a.PERSON_TO_MEET,a.DEPARTMENT_TEXT,a.FLOOR,b.BELONGING_T YPE,b.BELONGING_TEXT ,a.INTIME, c.EXIT_TIME FROM tm_visitor a LEFT JOIN tm_belonging b , tm_exit c ON
SELECT a.VISITOR_TEXT,a.COMPANY_TEXT,a.CONTACT,a.PERSON_TO_MEET,a.DEPARTMENT_TEXT,a.FLOOR,b.BELONGING_T
YPE,b.BELONGING_TEXT ,a.INTIME, c.EXIT_TIME FROM tm_visitor a LEFT JOIN tm_belonging b , tm_exit c ON a.ID=b.
BID AND a.ID=c.ID;
这就是您正在寻找的:
SELECT a.VISITOR_TEXT,
a.COMPANY_TEXT,
a.CONTACT,
a.PERSON_TO_MEET,
a.DEPARTMENT_TEXT,
a.FLOOR,
b.BELONGING_TYPE,
b.BELONGING_TEXT,
a.INTIME,
c.EXIT_TIME
FROM tm_visitor a
LEFT JOIN tm_belonging b ON b.BID = a.id
LEFT JOIN tm_exit c ON c.ID = a.ID
不能将
,
与联接语法一起使用。仅在from语法中。使用
SELECT a.VISITOR_TEXT, a.COMPANY_TEXT,a.CONTACT, a.PERSON_TO_MEET,a.DEPARTMENT_TEXT, a.FLOOR,b.BELONGING_TYPE,b.BELONGING_TEXT, a.INTIME, c.EXIT_TIME
FROM tm_visitor a
LEFT JOIN tm_belonging b ON a.ID=b.BID
left join tm_exit c ON a.ID=c.ID
@jcho360:我什么时候没有对帮助我的ppl表示感谢,我也表示了感谢,并接受了提供给我的答案
SELECT a.VISITOR_TEXT, a.COMPANY_TEXT,a.CONTACT, a.PERSON_TO_MEET,a.DEPARTMENT_TEXT, a.FLOOR,b.BELONGING_TYPE,b.BELONGING_TEXT, a.INTIME, c.EXIT_TIME
FROM tm_visitor a
LEFT JOIN tm_belonging b ON a.ID=b.BID
left join tm_exit c ON a.ID=c.ID