Java JDBC中，MySQL字段类型转换jdbcType

概述

MySQL里的数据字段类型与Java数据类型的对应标准。

1. 类型映射关系

MySQL类型类型、JDBC类型、Java类型的映射关系

MySQL                 数据类                 型	Java jdbcType	默认返回的Java类型
BIT(1) (new in MySQL-5.0)	BIT	java.lang.Boolean
TINYINT	TINYINT	java.lang.Boolean if the configuration property tinyInt1isBit is set to true (the default) and the storage size is 1, or java.lang.Integer if not.
BOOL, BOOLEAN	TINYINT	See TINYINT, above as these are aliases for TINYINT(1), currently.
SMALLINT[(M)] [UNSIGNED]	SMALLINT [UNSIGNED]	java.lang.Integer (regardless of whether it is UNSIGNED or not)
MEDIUMINT[(M)] [UNSIGNED]	MEDIUMINT [UNSIGNED]	java.lang.Integer (regardless of whether it is UNSIGNED or not)
INT,INTEGER[(M)] [UNSIGNED]	INTEGER [UNSIGNED]	java.lang.Integer, if UNSIGNED java.lang.Long
BIGINT[(M)] [UNSIGNED]	BIGINT [UNSIGNED]	java.lang.Long, if UNSIGNED java.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 is java.sql.Short. If set to true (the default), then the returned object is of type java.sql.Datewith 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

2. 类型转换关系

允许的跨类型相互转换的对应关系

MySQL数据类型	可转换为的Java类型
CHAR, VARCHAR, BLOB, TEXT, ENUM, and SET	java.lang.String，java.io.InputStream，java.io.Reader，java.sql.Blob，java.sql.Clob
FLOAT, REAL, DOUBLE PRECISION, NUMERIC, DECIMAL, TINYINT, SMALLINT, MEDIUMINT, INTEGER, BIGINT	java.lang.String, java.lang.Short, java.lang.Integer, java.lang.Long, java.lang.Double, java.math.BigDecimal
DATE, TIME, DATETIME, TIMESTAMP	java.lang.String, java.sql.Date, java.sql.Timestamp