Python-通过从B表中选择ID来更新一个表中多个记录的最快方法

Question

I have two tables in MySQL, which named A and B.

• A table scheme : a_id, u_id
• B table schema : b_id, u_id

I want to update B table u_id by selecting A table's u_id, with the condition a_id is equal to b_id.

For example, record in A looks like ('001', 'a00'),('003', 'a01'); record in B looks like ('001', ''), ('002', ''), ('003', '')

I want to update B table records with the result ('001', 'a00'), ('003', 'a01')

What is the fastest way to update the B table's u_id value? Thanks you.

Answer 1

Your query should look like this:

UPDATE tableB SET column2 = tableA.column2 WHERE tableB.column1 = tableA.column1

you can read up more on up update sql here .

Please let me know if you have any questions!