This query assigns a value to all records in the table, but I want to assign the value only to the last record

Question

I have two tables. One is publisher_info and the other one is unique_code . I want to assign the u_code column value from the unique_code table to the publisher_info.u_code column. Instead of assigning the value to last record, the query assigns and updated the value of all records. How can I fix this?

$record = "UPDATE publisher_info 
           SET u_code = (SELECT u_code 
                         FROM unique_code 
                         where unique_code.id = ".mysqli_insert_id($conn).")";

Answer 1

最终我得到了答案，查询最终成功了：$ record =“ UPDATE Publisher_info SET u_code =（从unique_code中选择u_code，其中unique_code.id = Publisher_info.id），其中Publisher_info.id =” .mysqli_insert_id（$ conn）。“”;

Answer 2

$ record =“ UPDATE Publisher_info SET u_code =（从unique_code ORDER BY unique_code.id DESC LIMIT 1中选择u_code）”；