在编程过程中遇到的一些问题，以及积累的一些经验在此简单总结一下。前车之鉴，后车之戒。
1.对于POJO类，什么时候用模型驱动，什么时候用属性驱动？
2.hibernate.cfg.xml中的<mapping resource="com/bean/Picture.hbm.xml"/>、<mapping resource="com/bean/User.hbm.xml"/>一定不能忘了！
3.Picture.hbm.xml中的<many-to-one name="user" cascade="all" class="com.bean.User" column="uId" />
一定不能写错！！！尤其是class属性！！！路径要写全！！！！！！类名要写对！！！！！！
4.小数1.0由前台页面保存到后台数据库怎么变成了1？在MySql中已把数据类型设置为double（10,1）。
5.jsp+servlet+MySql乱码问题？
6.JSF报如下异常： java.lang.RuntimeException: Cannot find FacesContext
可能的一种解决方案是：在web.xml中添加如下一段代码
<listener>
<listener-class>com.sun.faces.config.ConfigureListener</listener-class>
</listener>
7.今天写个web项目的时候，Eclipse 出现了这样一个错误：
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near…
花了好长时间才明白，原来使用了 MySQL 的关健字做字段名了！！
比如我用的desc做字段名，后来换了个字段名，问题就解决了。
下面列举下MySQL的关键字
| ADD | ALL | ALTER |
| ANALYZE | AND | AS |
| ASC | ASENSITIVE | BEFORE |
| BETWEEN | BIGINT | BINARY |
| BLOB | BOTH | BY |
| CALL | CASCADE | CASE |
| CHANGE | CHAR | CHARACTER |
| CHECK | COLLATE | COLUMN |
| CONDITION | CONNECTION | CONSTRAINT |
| CONTINUE | CONVERT | CREATE |
| CROSS | CURRENT_DATE | CURRENT_TIME |
| CURRENT_TIMESTAMP | CURRENT_USER | CURSOR |
| DATABASE | DATABASES | DAY_HOUR |
| DAY_MICROSECOND | DAY_MINUTE | DAY_SECOND |
| DEC | DECIMAL | DECLARE |
| DEFAULT | DELAYED | DELETE |
| DESC | DESCRIBE | DETERMINISTIC |
| DISTINCT | DISTINCTROW | DIV |
| DOUBLE | DROP | DUAL |
| EACH | ELSE | ELSEIF |
| ENCLOSED | ESCAPED | EXISTS |
| EXIT | EXPLAIN | FALSE |
| FETCH | FLOAT | FLOAT4 |
| FLOAT8 | FOR | FORCE |
| FOREIGN | FROM | FULLTEXT |
| GOTO | GRANT | GROUP |
| HAVING | HIGH_PRIORITY | HOUR_MICROSECOND |
| HOUR_MINUTE | HOUR_SECOND | IF |
| IGNORE | IN | INDEX |
| INFILE | INNER | INOUT |
| INSENSITIVE | INSERT | INT |
| INT1 | INT2 | INT3 |
| INT4 | INT8 | INTEGER |
| INTERVAL | INTO | IS |
| ITERATE | JOIN | KEY |
| KEYS | KILL | LABEL |
| LEADING | LEAVE | LEFT |
| LIKE | LIMIT | LINEAR |
| LINES | LOAD | LOCALTIME |
| LOCALTIMESTAMP | LOCK | LONG |
| LONGBLOB | LONGTEXT | LOOP |
| LOW_PRIORITY | MATCH | MEDIUMBLOB |
| MEDIUMINT | MEDIUMTEXT | MIDDLEINT |
| MINUTE_MICROSECOND | MINUTE_SECOND | MOD |
| MODIFIES | NATURAL | NOT |
| NO_WRITE_TO_BINLOG | NULL | NUMERIC |
| ON | OPTIMIZE | OPTION |
| OPTIONALLY | OR | ORDER |
| OUT | OUTER | OUTFILE |
| PRECISION | PRIMARY | PROCEDURE |
| PURGE | RAID0 | RANGE |
| READ | READS | REAL |
| REFERENCES | REGEXP | RELEASE |
| RENAME | REPEAT | REPLACE |
| REQUIRE | RESTRICT | RETURN |
| REVOKE | RIGHT | RLIKE |
| SCHEMA | SCHEMAS | SECOND_MICROSECOND |
| SELECT | SENSITIVE | SEPARATOR |
| SET | SHOW | SMALLINT |
| SPATIAL | SPECIFIC | SQL |
| SQLEXCEPTION | SQLSTATE | SQLWARNING |
| SQL_BIG_RESULT | SQL_CALC_FOUND_ROWS | SQL_SMALL_RESULT |
| SSL | STARTING | STRAIGHT_JOIN |
| TABLE | TERMINATED | THEN |
| TINYBLOB | TINYINT | TINYTEXT |
| TO | TRAILING | TRIGGER |
| TRUE | UNDO | UNION |
| UNIQUE | UNLOCK | UNSIGNED |
| UPDATE | USAGE | USE |
| USING | UTC_DATE | UTC_TIME |
| UTC_TIMESTAMP | VALUES | VARBINARY |
| VARCHAR | VARCHARACTER | VARYING |
| WHEN | WHERE | WHILE |
| WITH | WRITE | X509 |
| XOR | YEAR_MONTH | ZEROFILL |