将值从一个表复制到另一个表

Question

I'm trying to do SQL query to my DB. It must search for a row with the username in table1 and copy its id to a column in table2.

Example: Search for user "John" in table1 and copy John's id to table2:

table1:

id | username | points

table2:

id | user_id

I'm actually tried this:

INSERT INTO table2(table2.user_id) SELECT table1.id WHERE table1.username = "John";

But its not working. I don't have an idea how to do that? Could you help me?

Answer 1

Can you try this?

INSERT INTO table2 (user_id) SELECT t1.id FROM  table1 AS t1 WHERE  t1.username = 'John';

Note : This will work if column id on table1 is an identity (running number).