到 3.23.23 時，MySQL 開始支持全文索引和搜索。全文索引在 MySQL 中是一個 FULLTEXT 類型索引。FULLTEXT 索引用于 MyISAM 表，可以在 CREATE TABLE 時或之后使用 ALTER TABLE 或 CREATE INDEX 在 CHAR、VARCHAR 或 TEXT 列上創建。對于大的數據庫，將數據裝載到一個沒有 FULLTEXT 索引的表中，然后再使用 ALTER TABLE (或 CREATE INDEX) 創建索引，這將是非常快的。將數據裝載到一個已經有 FULLTEXT 索引的表中，將是非常慢的。
全文搜索通過 MATCH() 函數完成。
mysql> CREATE TABLE articles ( -> id INT UNSIGNED AUTO_INCREMENT NOT NULL PRIMARY KEY, -> title VARCHAR(200), -> body TEXT, -> FULLTEXT (title,body) -> ); Query OK, 0 rows affected (0.00 sec) mysql> INSERT INTO articles VALUES -> (NULL,'MySQL Tutorial', 'dbMS stands for DataBase ...'), -> (NULL,'How To Use MySQL Efficiently', 'After you went through a ...'), -> (NULL,'Optimising MySQL','In this tutorial we will show ...'), -> (NULL,'1001 MySQL Tricks','1. Never run mysqld as root. 2. ...'), -> (NULL,'MySQL vs. YourSQL', 'In the following database comparison ...'), -> (NULL,'MySQL Security', 'When configured properly, MySQL ...'); Query OK, 6 rows affected (0.00 sec) Records: 6 Duplicates: 0 Warnings: 0 mysql> select * FROM articles -> WHERE MATCH (title,body) AGAINST ('database'); +----+-------------------+------------------------------------------+ | id | title | body | +----+-------------------+------------------------------------------+ | 5 | MySQL vs. YourSQL | In the following database comparison ... | | 1 | MySQL Tutorial | DBMS stands for DataBase ... | +----+-------------------+------------------------------------------+ 2 rows in set (0.00 sec)
mysql> SELECT id,MATCH (title,body) AGAINST ('Tutorial') FROM articles; +----+-----------------------------------------+ | id | MATCH (title,body) AGAINST ('Tutorial') | +----+-----------------------------------------+ | 1 | 0.64840710366884 | | 2 | 0 | | 3 | 0.66266459031789 | | 4 | 0 | | 5 | 0 | | 6 | 0 | +----+-----------------------------------------+ 6 rows in set (0.00 sec)
下面的示例更復雜一點。查詢返回相似性并依然以相似度遞減的次序返回記錄行。為了完成這個結果，你應該指定 MATCH() 兩次。這不會引起附加的開銷，因為 MySQL 優化器會注意到兩次同樣的 MATCH() 調用，并只調用一次全文搜索代碼。
mysql> SELECT id, body, MATCH (title,body) AGAINST -> ('Security implications of running MySQL as root') AS SCOre -> FROM articles WHERE MATCH (title,body) AGAINST -> ('Security implications of running MySQL as root'); +----+-------------------------------------+-----------------+ | id | body | score | +----+-------------------------------------+-----------------+ | 4 | 1. Never run mysqld as root. 2. ... | 1.5055546709332 | | 6 | When configured properly, MySQL ... | 1.31140957288 | +----+-------------------------------------+-----------------+ 2 rows in set (0.00 sec)
mysql> SELECT * FROM articles WHERE MATCH (title,body) -> AGAINST ('+MySQL -YourSQL' IN BOOLEAN MODE); +----+------------------------------+-------------------------------------+ | id | title | body | +----+------------------------------+-------------------------------------+ | 1 | MySQL Tutorial | DBMS stands for DataBase ... | | 2 | How To Use MySQL Efficiently | After you went through a ... | | 3 | Optimising MySQL | In this tutorial we will show ... | | 4 | 1001 MySQL Tricks | 1. Never run mysqld as root. 2. ... | | 6 | MySQL Security | When configured properly, MySQL ... | +----+------------------------------+-------------------------------------+
這個查詢返回所有包含詞 MySQL 的記錄行(注意： 50% 的閾值沒有使用)，但是它沒有包含詞 YourSQL。注意，一個邏輯模式的搜索不會自動地以相似值的降序排序記錄行。你可以從上面的結果出看得出來，最高的相似值(包含 MySQL 兩次的那個) 最列在最后，而不是第一位。一個邏輯全文搜索即使在沒有一個 FULLTEXT 索引的情況下也可以工作，然而它 慢 些。
