Example shows how to update records in one table with data from another table.
CREATE TABLE table_a ( id INT(11) DEFAULT NULL, column_a INT(11) DEFAULT NULL ); CREATE TABLE table_b ( id INT(11) DEFAULT NULL, column_b INT(11) DEFAULT NULL ); INSERT INTO table_a VALUES (1, 10), (2, 20), (3, 30), (4, NULL), (5, 0); INSERT INTO table_b VALUES (1, 1), (2, NULL), (3, 0), (4, 4), (5, 5);
Update data:
UPDATE table_a a JOIN table_b b ON a.id = b.id SET b.column_b = a.column_a;
Result table:
SELECT * FROM table_b; +------+----------+ | id | column_b | +------+----------+ | 1 | 10 | | 2 | 20 | | 3 | 30 | | 4 | NULL | | 5 | 0 | +------+----------+
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