数据库中查询的各种连接?? 表a表b??左连接 ?select * from a left join b on a.aidb.bid ???右连接?selec
数据库中查询的各种连接
?? 表a
表b
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?左连接 ?select * from a left join b on a.aid=b.bid
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?右连接?select * from a right join b on a.aid=b.bid?
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内连接：select * from a inner join b on a.aid=b.bid?
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全连接：select * from a full join b on a.aid=b.bid?
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交叉连接：select * from a cross join b?
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