Java和MySQL数据类型对应一览

Table 20.25. MySQL Types to Java Types for ResultSet.getObject()
MySQL Type Name	Return value ofGetColumnClassName	Returned as Java Class
BIT(1) (new in MySQL-5.0)	BIT	java.lang.Boolean
BIT( > 1) (new in MySQL-5.0)	BIT	byte[]
TINYINT	TINYINT	java.lang.Boolean if the configuration property tinyInt1isBit is set to true (the default) and the storage size is 1, orjava.lang.Integer if not.
BOOL, BOOLEAN	TINYINT	See TINYINT, above as these are aliases forTINYINT(1), currently.
SMALLINT[(M)] [UNSIGNED]	SMALLINT [UNSIGNED]	java.lang.Integer (regardless ifUNSIGNED or not)
MEDIUMINT[(M)] [UNSIGNED]	MEDIUMINT [UNSIGNED]	java.lang.Integer, if UNSIGNEDjava.lang.Long (C/J 3.1 and earlier), orjava.lang.Integer for C/J 5.0 and later
INT,INTEGER[(M)] [UNSIGNED]	INTEGER [UNSIGNED]	java.lang.Integer, if UNSIGNEDjava.lang.Long
BIGINT[(M)] [UNSIGNED]	BIGINT [UNSIGNED]	java.lang.Long, if UNSIGNEDjava.math.BigInteger
FLOAT[(M,D)]	FLOAT	java.lang.Float
DOUBLE[(M,B)]	DOUBLE	java.lang.Double
DECIMAL[(M[,D])]	DECIMAL	java.math.BigDecimal
DATE	DATE	java.sql.Date
DATETIME	DATETIME	java.sql.Timestamp
TIMESTAMP[(M)]	TIMESTAMP	java.sql.Timestamp
TIME	TIME	java.sql.Time
YEAR[(2|4)]	YEAR	If yearIsDateType configuration property is set to false, then the returned object type isjava.sql.Short. If set to true (the default), then the returned object is of typejava.sql.Date with the date set to January 1st, at midnight.
CHAR(M)	CHAR	java.lang.String (unless the character set for the column is BINARY, then byte[] is returned.
VARCHAR(M) [BINARY]	VARCHAR	java.lang.String (unless the character set for the column is BINARY, then byte[] is returned.
BINARY(M)	BINARY	byte[]
VARBINARY(M)	VARBINARY	byte[]
TINYBLOB	TINYBLOB	byte[]
TINYTEXT	VARCHAR	java.lang.String
BLOB	BLOB	byte[]
TEXT	VARCHAR	java.lang.String
MEDIUMBLOB	MEDIUMBLOB	byte[]
MEDIUMTEXT	VARCHAR	java.lang.String
LONGBLOB	LONGBLOB	byte[]
LONGTEXT	VARCHAR	java.lang.String
ENUM('value1','value2',...)	CHAR	java.lang.String
SET('value1','value2',...)	CHAR	java.lang.String

对于boolean类型，在mysql数据库中，个人认为用int类型代替较好，对bit操作不是很方便，尤其是在具有web页面开发的项目中，表示0/1，对应java类型的Integer较好。

我的概念中,mysql中的text字段应该是没有长度限制的,但是今天事实告诉我,text类型的长度是有限制的。其中mysql的text类型有64K长度限制的

工作中由于邮件的长度超过了64k,Text已经不适用，我们换用了MEDIUMTEXT 他的长度为16777215 (2^24 - 1) 为256*64K=16M