Använd den utmärkta funktionen från denna fråga av @otis i din fråga:
mysql> select * from test;
+----+------------------------------+
| id | sentence |
+----+------------------------------+
| 0 | Hello World |
| 1 | Hello World |
| 2 | Mary had a little lamb |
| 3 | Her fleece was white as snow |
| 4 | Everywhere that mary went |
| 5 | Umm, sheep followed her |
+----+------------------------------+
6 rows in set (0.00 sec)
mysql> SELECT sentence, wordcount(sentence) as "Words" from test;
+------------------------------+-------+
| sentence | Words |
+------------------------------+-------+
| Hello World | 2 |
| Hello World | 2 |
| Mary had a little lamb | 5 |
| Her fleece was white as snow | 6 |
| Everywhere that mary went | 4 |
| Umm, sheep followed her | 4 |
+------------------------------+-------+
6 rows in set (0.02 sec)
För att få funktionen att fungera måste du utföra deklarationen av funktionen i MySQL. Det är precis som att köra vilken annan fråga som helst:
mysql> DELIMITER $$
mysql> CREATE FUNCTION wordcount(str TEXT)
RETURNS INT
DETERMINISTIC
SQL SECURITY INVOKER
NO SQL
BEGIN
DECLARE wordCnt, idx, maxIdx INT DEFAULT 0;
DECLARE currChar, prevChar BOOL DEFAULT 0;
SET maxIdx=char_length(str);
WHILE idx < maxIdx DO
SET currChar=SUBSTRING(str, idx, 1) RLIKE '[[:alnum:]]';
IF NOT prevChar AND currChar THEN
SET wordCnt=wordCnt+1;
END IF;
SET prevChar=currChar;
SET idx=idx+1;
END WHILE;
RETURN wordCnt;
END
$$
Query OK, 0 rows affected (0.10 sec)
mysql> DELIMITER ;