順便提一下MySQL中正規表達式比對的簡單使用：SELECT COUNT(alarmID)FROM AlarmWHERE (CVE NOT RLIKE
mysql> SELECT COUNT(name) FROM CVE WHERE name NOT IN ('CVE-1999-0001', 'CVE-1999-0002');
+-------------+
| count(name) |
+-------------+
| 17629 |
+-------------+
1 row in set (0.02 sec)
mysql> SELECT COUNT(name) FROM CVE WHERE name NOT IN ('CVE-1999-0001', 'CVE-1999-0002', NULL);
+-------------+
| count(name) |
+-------------+
| 0 |
+-------------+
1 row in set (0.01 sec)
當在子查詢中出現NULL的時候，結果就一定是0了。查了一下手冊，确實有這樣的說法。是以最後實際采用了這樣的查詢：
SELECT COUNT(DISTINCT name)
FROM CVE
WHERE name NOT IN (SELECT cveID FROM cve_sig WHERE cveID IS NOT NULL)
順便提一下MySQL中正規表達式比對的簡單使用：
SELECT COUNT(alarmID)
FROM Alarm
WHERE (CVE NOT RLIKE '^CVE-[0-9]{4}-[0-9]{4}$' OR CVE IS NULL)
當然，RLIKE也可以寫作REGEXP，我個人傾向于使用RLIKE，因為拼寫接近LIKE，可以見名知義。
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