SQL copy data from a column to another column from another table-CodePudding

I have two tables DEP and DEPARTMENTS.

I want to copy the data from DEPARTMENT's column called ID_DEPARTMENT to DEP's column called ID, but I keep getting either errors or says that nothing was updated.

CodePudding user response：

Assuming that there is just that column then you can copy the data and insert it into new rows using:

INSERT INTO dep (id )
SELECT id_department FROM DEPARTMENTS;

Which, for the sample data:

CREATE TABLE departments (id_department, col1, col2, col3) AS
SELECT LEVEL, 'a'||LEVEL, 'b'||LEVEL, 'c'||LEVEL FROM DUAL CONNECT BY LEVEL <= 5;

CREATE TABLE dep(id INT);

Then, after the INSERT:

SELECT * FROM dep;

Outputs:

ID

1

2

3

4

5

ID
1
2
3
4
5

db<>fiddle here