oracle 数据库sql 查询语句。通过一个sql语句对多个表分别进行...答:用union,举例有S1表(a,b,c,d)和S2表(a,c,d,e)和S3表(f,g),里头的字段不同,但在逻辑上有关系 (如有 s1.b=s2.e s1.a=s3.f s1.b=s3.g)示例如下:--- select S1.a as x,S1.b as y,S1.c as z from S1 union select S2.a as x,S2.e as y,S2.c as ...
从多个表中查询数据的sql语句答:用union,举例有s1表(a,b,c,d)和s2表(a,c,d,e)和s3表(f,g),里头的字段不同,但在逻辑上有关系 (如有 s1.b=s2.e s1.a=s3.f s1.b=s3.g)示例如下:--- select s1.a as x,s1.b as y,s1.c as z from s1 union select s2.a as x,s2.e as y,s2.c as ...