我有以下当前表:
table_1
id | timestamp | origin | info
table_2
id | timestamp | origin | type
我的目标是为表2中的每一行找到表1中的origin事件。我只想保留第一个事件。 例如:
table 1
1 | 1000 | "o1" | "i1"
2 | 2000 | "o2" | "i2"
3 | 2010 | "o2" | "i2"
table 2
1 | 1010 | "o1" | "t1"
2 | 2100 | "o2" | "t2"
我的预期结果是:
table_2.id | table_2.timestamp | table_2.origin | table_2.type | table_1.info | table_1.timestamp
1 | 1010 | "o1" | "t1" | "i1" | 1000
2 | 2100 | "o2" | "t2" | "i2" | 2010
目前,我只是在origin
和table_2.timestamp > table_1.timestamp
上使用简单的联接,这给了我
table_2.id | table_2.timestamp | table_2.origin | table_2.type | table_1.info | table_1.timestamp
1 | 1010 | "o1" | "t1" | "i1" | 1000
2 | 2100 | "o2" | "t2" | "i2" | 2000
2 | 2100 | "o2" | "t2" | "i2" | 2010
如您所见,我不需要上面的第二行,因为我只想要table_1中最接近的事件。
有什么想法吗?