Reference Manual
   CHAPTER 7. SQL Data Types     

Java / SQL data type conversion

When a Java class field or method is invoked within a SQL statement, a Java data type is returned by the Java object. This must be converted into a SQL data type for use within the SQL statement, for example in comparisons.

Similarly, when a SQL statement is included in a JDBC class, it provides data of SQL data types, which must be converted to Java data types.

Java to SQL and SQL to Java data type conversions are carried out according to the JDBC standard. The conversions are described in the following tables.

  Java to-SQL-data type conversion

Java type	SQL type
String	CHAR
String	VARCHAR
String	TEXT
java.math.BigDecimal	NUMERIC
Java.math.BigDecimal	MONEY
Java.math.BigDecimal	SMALLMONEY
Boolean	BIT
Byte	TINYINT
short	SMALLINT
int	INTEGER
long	INTEGER
float	REAL
double	DOUBLE
byte[ ]	VARBINARY
Byte[ ]	IMAGE
java.sql.Date	DATE
java.sql.Time	TIME
java.sql.Timestamp	TIMESTAMP
java.lang.Double	DOUBLE
java.lang.Float	REAL
java.lang.Integer	INTEGER
java.lang.Long	INTEGER

  SQL-to-Java data type conversion

SQL type	Java type
CHAR	String
VARCHAR	String
TEXT	String
NUMERIC	java.math.BigDecimal
DECIMAL	java.math.BigDecimal
MONEY	java.math.BigDecimal
SMALLMONEY	Java.math.BigDecimal
BIT	boolean
TINYINT	byte
SMALLINT	short
INTEGER	int
BIGINT	long
REAL	float
FLOAT	double
DOUBLE	double
BINARY	byte[ ]
VARBINARY	byte[ ]
LONG VARBINARY	byte[ ]
IMAGE	Byte[ ]
DATE	java.sql.Date
TIME	java.sql.Time
TIMESTAMP	java.sql.Timestamp