Insert distinct values from one table into another table

Question

So for each distinct value in a column of one table I want to insert that unique value into a row of another table.

list = select distinct(id) from table0

for distinct_id in list
 insert into table1 (id) values (distinct_id)
end

Any ideas as to how to go about this?

Answer 1

Whenever you think about doing something in a loop, step back, and think again. SQL is optimized to work with sets. You can do this using a set-based query without the need to loop:

INSERT dbo.table1(id) SELECT DISTINCT id FROM dbo.table0;

There are some edge cases where looping can make more sense, but as SQL Server matures and more functionality is added, those edge cases get narrower and narrower...

Answer 2

insert into table1 (id)
select distinct id from table0

Answer 3

以下声明适用于我。

insert into table1(col1, col2) select distinct on (col1) col1 col2 from table0 

Answer 4

下面的查询还将检查表 2 中的现有数据。

INSERT INTO Table2(Id) SELECT DISTINCT Id FROM Table1 WHERE Id NOT IN(SELECT Id FROM Table2);

Answer 5

Other Simple way to copy distinct data with multiple columns from one table to other

Insert into TBL2 
Select * from (Select COL1, ROW_NUMBER() over(PARTITION BY COL1 Order By COL1) AS COL2 From TBL1)T
where T.COL2 = 1