弱智问题一:
在往MySql的表中插数据时,老是报SQL Error: 1064, SQLState: 42000错误,郁闷了好半天,上网搜了才发现,是因为表中字段的名字用了MySql的关键字,晕倒,以后一定要注意。
MySQL的保留字有以下这些,使用中需要注意。(从网上打劫过来的)
| 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 |
弱智问题二:
需要同事帮忙调整程序,但是同事却死人的连不上我机器上的MySql,继续郁闷,继续网上搜索。
发现一个补救办法是:让mysql库中user表的host字段为“%”,以接受远程控制,这样别人就可以用mysql -h ***.***.***.***(你的IP) -u root -p密码 进行连接并操作数据库了。
还有一个是在安装时需要注意的:在设置用户的时候会有一个复选框,问是否让别人连接,这里需要选中!
弱智问题三:
用Hibernate,设置PO映射文件的主键字段的属性为“natively”(<id name="logId" type="integer" column="LOGID"><generator class="native"/></id>),但是往表里面查数据时老是说“The database returned no natively generated identity value”。
最后确认是在表的属性中没有设置主键为“auto increment”,这个可以用数据库连接工具在表属性中设置,也可以在建表的时候,在主键字段后面标注上:CREATE TABLE `log` (`LOGID` int(11) NOT NULL auto_increment, PRIMARY KEY (`LOGID`)) ENGINE=InnoDB DEFAULT CHARSET=gbk
弱智问题四:
做报表的时候,需要查出内容为Null的记录,在查询条件里面写了“XX=null”,结果怎么也查不出来,郁闷半天,后来试了下“XX is null”,就查出来了,哎,俺真是够白痴的了!
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