MySQL 8.0 Release Notes
MySQL 8.0 Source Code Documentation
This section describes how to add a new collation for full-text
searches using the built-in full-text parser. The sample
collation is like latin1_swedish_ci but
treats the '-' character as a letter rather
than as a punctuation character so that it can be indexed as a
word character. General information about adding collations is
given in Section 10.13, “Adding a Collation to a Character Set”; it is assumed that
you have read it and are familiar with the files involved.
To add a collation for full-text indexing, use the following procedure. The instructions here add a collation for a simple character set, which as discussed in Section 10.13, “Adding a Collation to a Character Set”, can be created using a configuration file that describes the character set properties. For a complex character set such as Unicode, create collations using C source files that describe the character set properties.
Add a collation to the
Index.xmlfile. The collation ID must be unused, so choose a value different from 1000 if that ID is already taken on your system.<charset name="latin1"> ... <collation name="latin1_fulltext_ci" id="1000"/> </charset>Declare the sort order for the collation in the
latin1.xmlfile. In this case, the order can be copied fromlatin1_swedish_ci:<collation name="latin1_fulltext_ci"> <map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map> </collation>Modify the
ctypearray inlatin1.xml. Change the value corresponding to 0x2D (which is the code for the'-'character) from 10 (punctuation) to 01 (uppercase letter). In the following array, this is the element in the fourth row down, third value from the end.<ctype> <map> 00 20 20 20 20 20 20 20 20 20 28 28 28 28 28 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 48 10 10 10 10 10 10 10 10 10 10 10 10 01 10 10 84 84 84 84 84 84 84 84 84 84 10 10 10 10 10 10 10 81 81 81 81 81 81 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 10 10 10 10 10 10 82 82 82 82 82 82 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 10 10 10 10 20 10 00 10 02 10 10 10 10 10 10 01 10 01 00 01 00 00 10 10 10 10 10 10 10 10 10 02 10 02 00 02 01 48 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 10 01 01 01 01 01 01 01 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 10 02 02 02 02 02 02 02 02 </map> </ctype>Restart the server.
To employ the new collation, include it in the definition of columns that are to use it:
mysql> DROP TABLE IF EXISTS t1; Query OK, 0 rows affected (0.13 sec) mysql> CREATE TABLE t1 ( a TEXT CHARACTER SET latin1 COLLATE latin1_fulltext_ci, FULLTEXT INDEX(a) ) ENGINE=InnoDB; Query OK, 0 rows affected (0.47 sec)Test the collation to verify that hyphen is considered as a word character:
mysql> INSERT INTO t1 VALUEs ('----'),('....'),('abcd'); Query OK, 3 rows affected (0.22 sec) Records: 3 Duplicates: 0 Warnings: 0 mysql> SELECT * FROM t1 WHERE MATCH a AGAINST ('----' IN BOOLEAN MODE); +------+ | a | +------+ | ---- | +------+ 1 row in set (0.00 sec)