mysql SQL statement to copy the contents of a field from one table to a field from another table

Requirement: Copy the contents of a field in one table to a field in another table.

sql statement 1:

UPDATE file_manager_folder f1
LEFT OUTER JOIN file_manager_folder f2 
    ON f1.name = f2.name AND f2.parentId = 54
SET f1.parentId = 54 
WHERE f2.name IS NULL AND f1.id IN (1,2,3);

Implement sql statement 2:

update B set extra = A.extra from A join B on (A.id = B.id);

Implement sql statement 3:

update b set b.sms = (select a.sms from a where a.id = b.id)

You need to make sure that id in both tables is the primary key or the only one

sql statement 4:

UPDATE A SET A.SMS = (SELECT B.SMS FROM B WHERE A.ID = B.ID) WHERE EXISTS (SELECT 1 FROM B WHERE A.ID = B.ID);

Realize sql statement 5:
Copy the data from one table field to the field of another table by writing:
sql statement 5:

UPDATE tb_1 INNER JOIN tb_2 ON tb_1.tid = tb_2.tid
SET tb_1.tcontent = tb_2.tcontent

Attached: same as table copy

Requirement: Copy the contents of one field from the same table to another field

Case 1:
I want to copy the contents of the A field in the article table to the B field in the article table. The sql statement is:

update article set B=A;

Example 2:
Sometimes we need to copy an entire column of data from one field to a new field. This can be as simple as SQL writing:

UPDATE tb_1 SET content_target = content_source;

Roughly written as follows:

Update {your_table} set {source_field} = {object_field} WHERE cause