javascript - How to avoid duplication with data in the library when inserting data in mysql?

Question

How to avoid duplication of already inserted data when inserting data into a mysql database table? What should I do? Please advise, thank you!

Answer 1

Create unique index

Single key index:
create unique index UNIQUE_PERSON_NICK_NAME_INDEX ON Person (NickName) create unique index UNIQUE_PERSON_NICK_NAME_INDEX ON Person (NickName)
双键索引：
create unique index UNIQUE_PERSON_FULL_NAME_INDEX ON Person (LastName, FirstName)Double key index:

create unique index UNIQUE_PERSON_FULL_NAME_INDEX ON Person (LastName, FirstName)

MYSQL complete index creation syntax:

MYSQL5.7 CREATE INDEX Syntax🎜

Answer 2

When you say repetition, do you mean one field is repeated or all fields are repeated?

Answer 3

Some usage summary of insert ignore into, replace into, etc. in MySQL