[英]Merge two tables sql
This is my data set: Dataset 1: 这是我的数据集:数据集1:
col2 col3 col4
1 2 3
1 5 6
Dataset 2: 数据集2:
name2 name3 name4
a b c
d e l
I want to merge these two table like this: 我想像这样合并这两个表:
col2 col3 col4 name2 name3 name4
1 2 3 a b c
1 5 6 d e l
I've tried with: 我尝试过:
select * from table1 join table2 on true;
but gives me: 但是给我:
col2 col3 col4 name2 name3 name4
1 2 3 a b c
1 2 3 d e l
Which isn't correct. 这是不正确的。 How could i achieve this?
我怎样才能做到这一点?
Your result should have been four records. 您的结果应该是四个记录。
You need a common key to join on, but don't have one. 您需要一个公共密钥才能加入,但没有一个。 Here is one method:
这是一种方法:
select t1.col2, t1.col3, t1.col4, t2.name2, t2.name3, t2.name4
from (select t1.*, row_number() over () as seqnum
from table1 t1
) t1 join
(select t2.*, row_number() over () as seqnum
from table2 t2
) t2
on t1.seqnum = t2.seqnum;
Note that the ordering of the rows (defining the matching) is indeterminate. 请注意,行的顺序(定义匹配项)是不确定的。 If this is important, then include
order by
clauses in the row_number()
with the appropriate ordering. 如果这很重要,则在
row_number()
包括有适当顺序的order by
子句。
据我所知,这应该工作:
SELECT * FROM table1 JOIN table2 ON table1.row_number()=table2.row_number();
在这种情况下,您不需要加入。您只需从两个表中进行选择即可。从table1,table2中选择*。
You don't need JOIN
in this case if you want, you can get all columns like this (Because if the same number of columns in both tables): 在这种情况下,如果需要,则不需要
JOIN
,就可以像这样获得所有列(因为如果两个表中的列数相同):
SELECT col2,col3,col4 FROM dataset1
UNION
SELECT name2,name3,name4 FROM dataset2
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