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)
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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)
MYSQL5.7 CREATE INDEX Syntax🎜MYSQL complete index creation syntax:
When you say repetition, do you mean one field is repeated or all fields are repeated?
Some usage summary of insert ignore into, replace into, etc. in MySQL