CREATE INDEX statement in SQL is used to create indexes in tables. The indexes are used to retrieve data from the database more quickly than ... ... <看更多>

An index literally stores a copy of the data, sorted on the fields covered by that index (and automatically includes the clustered index ... ... <看更多>

In MySQL, if you use ALTER TABLE tbl ADD INDEX (col) instead of ALTER TABLE tbl ADD INDEX col (col) , then using ALTER TABLE tbl ADD INDEX (col) ... ... <看更多>

MySQL : Create index if not exists. GitHub Gist: instantly share code, notes, and snippets. ... <看更多>