MySQL field processing methods

How to deal with the uniqueness of multiple fields?

• Scenario

There is a table with multiple fields that need to be unique and cannot be repeated, otherwise they will be duplicates Data cannot be inserted

• Traditional approach

Add unique indexes directly to multiple fields, simple and crude

• Now how to do it

Add a new field and add a unique index to this field, so you don’t need to add too many unique indexes

insert into news(new_title, new_abstr, new_code) 
values('你是好'，'我是谁',MD5(CONCAT('你是好'，'我是谁')))

How to handle it if the data exists, it is updated, if it does not exist, it is inserted?

• Scenario

There is a table. The records in it cannot have duplicate records. If the record exists, it will be updated. If not If it exists, insert it

• Traditional approach

Query the select first, if it exists, update it, if it does not exist, update it

• The current practice

mysql has a special writing method, on DUPLICATE key Update

insert into news(new_title, new_abstr, new_code, update_time, create_time) 
values('你是好'，'我是谁',MD5(CONCAT('你是好'，'我是谁')))
on DUPLICATE key Update
update_time=now(), create_time=now()

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