Advanced Database Persistence for Java

Examples & Reference Manual
 

IBM DB2

The HotRod DB2 adapter automatically maps known database column types to DAO Java types. In most of the cases this default Java type is well suited to handle the database values. However, when needed the default Java type of a property can be overridden by a custom type if it's provided by the developer.

Default Java Types

If a custom Java type is not specified HotRod will use the following rules to decide which Java type to use for each Oracle column. In yellow is the DAO property type. In parenthesis the actual object type returned by the IBM DB2 JDBC driver, that on occasions may be different.

Please note that the Java types for the IBM DB2 columns may vary depending on the specific version and variant of the RDBMS, the operating system where the database engine is running, and the JDBC driver version.

DB2 Column Type Default Java Type
SMALLINT java.lang.Short
INTEGER,
INT 		java.lang.Integer
BIGINT java.lang.Long
DECIMAL(p,s),
DEC(p,s),
NUMERIC(p,s),
NUM(p,s) 		If s is specified and different from zero the Java type is:
  • java.math.BigDecimal
if s is not specified or it's zero:
  • if p <= 2: java.lang.Byte
  • if 2 < p <= 4: java.lang.Short
  • if 4 < p <= 9: java.lang.Integer
  • if 8 < p <= 18: java.lang.Long
  • if p > 18: java.math.BigInteger
DECFLOAT java.math.BigDecimal
REAL java.lang.Float
FLOAT,
DOUBLE 		java.lang.Double
CHAR(n),
CHARACTER(n),
VARCHAR(n),
CHARACTER VARYING(n),
CLOB(n),
GRAPHIC(n),
NCHAR(n),
VARGRAPHIC(n),
NVARCHAR(n),
DBCLOB(n),
NCLOB(n),
LONG VARCHAR,
LONG VARGRAPHIC 		java.lang.String
VARCHAR FOR BIT DATA,
LONG VARCHAR FOR BIT DATA,
CHAR(n) FOR BIT DATA,
BLOB(n) 		byte[]
DATE java.sql.Date
TIME java.sql.Time
TIMESTAMP java.sql.Timestamp
XML java.lang.String
BOOLEAN (pseudo type) java.lang.String
BINARY No default HotRod data type
VARBINARY No default HotRod data type
ROW No default HotRod data type
ARRAY No default HotRod data type

Custom Java Types

To override the default Java type see the reference section for the tables, views, and selects. The Example 19 - Custom DAO Property Java Types shows a case where a custom type overrides the default type. To override the default type add a <column> tag in a <table> , <view> , or <select> definition.