Type Support

The table recommends Java property types for common Dameng columns. Use wrapper types for nullable fields. NUMBER precision does not select a Java type automatically. See Java/JDBC types.

Common Types

Database column type	Java type	Notes
BIT	Boolean	0 is false and a nonzero value is true.
TINYINT	Byte	Signed integer from -128 to 127.
BYTE	Byte	Integer with precision 3 and scale 0.
SMALLINT	Short	Signed integer from -32768 to 32767.
INTEGER	Integer	Signed 32-bit integer.
INT	Integer	Synonym for INTEGER.
BIGINT	Long	Signed 64-bit integer.
NUMERIC(p, s)	BigDecimal	Precision is at most 38; writes are constrained by the column precision and scale.
DECIMAL(p, s)	BigDecimal	Similar semantics to NUMERIC.
DEC(p, s)	BigDecimal	Synonym for DECIMAL.
NUMBER(p, s)	BigDecimal	Same semantics as NUMERIC.
REAL	Float	Single-precision approximate number.
FLOAT(p)	Float / Double	Stored as single precision when p is at most 24 and as double precision when p is greater than 24. Choose the Java property from the column definition.
DOUBLE	Double	Double-precision approximate number.
DOUBLE PRECISION	Double	Double-precision approximate number.
CHAR(n)	String	Fixed-length string; the database pads shorter values with spaces.
CHARACTER(n)	String	Synonym for CHAR.
VARCHAR(n)	String	Variable-length string.
VARCHAR2(n)	String	Same usage as VARCHAR.
TEXT	String	Large text. For JSON text, see JSON Field Mapping.
LONG	String	Synonym for TEXT.
LONGVARCHAR	String	Synonym for TEXT.
CLOB	String	Large text. For JSON text, see JSON Field Mapping.
BINARY(n)	byte[]	Fixed-length binary content.
VARBINARY(n)	byte[]	Variable-length binary content.
RAW(n)	byte[]	Synonym for VARBINARY.
IMAGE	byte[]	Binary large object; it may also hold non-image binary content.
LONGVARBINARY	byte[]	Synonym for IMAGE.
BLOB	byte[]	Binary large object.
DATE	java.sql.Date	Contains only year, month, and day.
TIME	java.sql.Time	Contains only time fields; fractional-second precision defaults to 0 when omitted.
TIME(p)	String	When p is from 1 through 6 and fractional seconds must be preserved, use a string or a Dameng JDBC extension object; java.sql.Time cannot represent that precision completely.
TIMESTAMP(p)	java.sql.Timestamp	Contains date and time; Dameng supports fractional-second precision up to 9. DATETIME is a synonym.
ROWID	String	An 18-character value used for a Dameng row identifier.

Scale-zero NUMERIC, DECIMAL, DEC, and NUMBER columns may also map to integer types, but the application must ensure that values have no fractional part and fit the selected Java range. Prefer BigDecimal when the complete column range must be preserved.

Interval Types

Dameng JDBC provides extension objects for interval types. The official driver also permits reading and writing them with getString and setString. Use String when the entity only needs to preserve the complete literal value:

Database column type	Java type	Notes
INTERVAL YEAR	String	Year interval; the value must follow the Dameng interval literal format.
INTERVAL MONTH	String	Month interval; the value must follow the Dameng interval literal format.
INTERVAL YEAR TO MONTH	String	Year-to-month interval.
INTERVAL DAY	String	Day interval.
INTERVAL DAY TO HOUR	String	Day-to-hour interval.
INTERVAL DAY TO MINUTE	String	Day-to-minute interval.
INTERVAL DAY TO SECOND	String	Day-to-second interval, optionally with fractional seconds.
INTERVAL HOUR	String	Hour interval.
INTERVAL HOUR TO MINUTE	String	Hour-to-minute interval.
INTERVAL HOUR TO SECOND	String	Hour-to-second interval, optionally with fractional seconds.
INTERVAL MINUTE	String	Minute interval.
INTERVAL MINUTE TO SECOND	String	Minute-to-second interval, optionally with fractional seconds.
INTERVAL SECOND	String	Second interval, optionally with fractional seconds.

When individual year, month, day, hour, minute, or second components are required, use the Dameng JDBC extension object through a custom mapping. dbVisitor does not automatically convert those proprietary objects to java.time.Duration or Period.

Example: Declare Entity Properties

import java.math.BigDecimal;
import java.sql.Date;
import java.sql.Timestamp;
import net.hasor.dbvisitor.mapping.Column;

@Column("quantity")
private Short quantity;       // SMALLINT

@Column("amount")
private BigDecimal amount;    // NUMBER(10, 2)

@Column("business_date")
private Date businessDate;    // DATE

@Column("created_at")
private Timestamp createdAt;  // TIMESTAMP(6)

@Column("payload")
private byte[] payload;       // BLOB

Boundaries

• BFILE is a read-only server-side file, not a BLOB.
• Use a custom mapping or RowMapper for zoned time types and XMLTYPE.
• Use NUMBER with BigDecimal for exact decimals, not a floating-point type.
• Use Timestamp for TIMESTAMP. Use text or a Dameng JDBC extension object when TIME(p) fractional seconds must be preserved.