Type Mapping¶

sqlalchemy_altibase.types provides Altibase-aware SQLAlchemy type classes and compiler mappings.

Type families¶

```mermaid classDiagram class sqltypes_NUMERIC class sqltypes_FLOAT class sqltypes_INTEGER class sqltypes_String class sqltypes_Text class sqltypes_LargeBinary class sqltypes_DATE class sqltypes_TypeEngine

class NUMERIC
class DECIMAL
class FLOAT
class REAL
class DOUBLE
class SMALLINT
class INTEGER
class BIGINT
class SERIAL
class VARCHAR
class CHAR
class NCHAR
class NVARCHAR
class CLOB
class BLOB
class DATE
class BIT
class VARBIT
class BYTE
class VARBYTE
class NIBBLE
class GEOMETRY

sqltypes_NUMERIC <|-- NUMERIC
sqltypes_NUMERIC <|-- DECIMAL
sqltypes_FLOAT <|-- FLOAT
sqltypes_FLOAT <|-- REAL
sqltypes_FLOAT <|-- DOUBLE
sqltypes_INTEGER <|-- SMALLINT
sqltypes_INTEGER <|-- INTEGER
sqltypes_INTEGER <|-- BIGINT
sqltypes_INTEGER <|-- SERIAL
sqltypes_String <|-- VARCHAR
sqltypes_String <|-- CHAR
sqltypes_String <|-- NCHAR
sqltypes_String <|-- NVARCHAR
sqltypes_Text <|-- CLOB
sqltypes_LargeBinary <|-- BLOB
sqltypes_DATE <|-- DATE
sqltypes_TypeEngine <|-- BIT
sqltypes_TypeEngine <|-- VARBIT
sqltypes_LargeBinary <|-- BYTE
sqltypes_LargeBinary <|-- VARBYTE
sqltypes_TypeEngine <|-- NIBBLE
sqltypes_TypeEngine <|-- GEOMETRY

```

Complete type list (22 classes)¶

Numeric¶

NUMERIC(precision=None, scale=None)
DECIMAL(precision=None, scale=None)
FLOAT(precision=None)
REAL()
DOUBLE()
SMALLINT()
INTEGER()
BIGINT()
SERIAL()

Character / text¶

VARCHAR(length=None)
CHAR(length=None)
NCHAR(length=None)
NVARCHAR(length=None)
CLOB()

Binary / bit / other Altibase-specific¶

BLOB()
DATE()
BIT(length=None)
VARBIT(length=None)
BYTE(length=None)
VARBYTE(length=None)
NIBBLE(length=None)
GEOMETRY()

Unique Altibase-oriented types

SERIAL, BIT, VARBIT, BYTE, VARBYTE, NIBBLE, and GEOMETRY are central Altibase-focused additions provided by this dialect package.

`ischema_names` reflection mapping¶

The dialect maps reflected Altibase type names to SQLAlchemy type classes using ischema_names:

Reflected type name	Mapped class
NUMBER	`NUMERIC`
NUMERIC	`NUMERIC`
DECIMAL	`DECIMAL`
FLOAT	`FLOAT`
REAL	`REAL`
DOUBLE	`DOUBLE`
SMALLINT	`SMALLINT`
INTEGER	`INTEGER`
INT	`INTEGER`
BIGINT	`BIGINT`
SERIAL	`SERIAL`
VARCHAR	`VARCHAR`
CHAR	`CHAR`
NCHAR	`NCHAR`
NVARCHAR	`NVARCHAR`
CLOB	`CLOB`
BLOB	`BLOB`
DATE	`DATE`
TIMESTAMP	`DATE`
BYTE	`BYTE`
NIBBLE	`NIBBLE`
BIT	`BIT`
VARBIT	`VARBIT`
VARBYTE	`VARBYTE`
GEOMETRY	`GEOMETRY`

Type compiler visit methods¶

AltibaseTypeCompiler implements explicit rendering for:

visit_BOOLEAN -> SMALLINT
visit_NUMERIC, visit_DECIMAL, visit_FLOAT (precision/scale aware)
visit_REAL, visit_DOUBLE, visit_SMALLINT, visit_INTEGER, visit_BIGINT, visit_SERIAL
visit_VARCHAR, visit_CHAR, visit_NCHAR, visit_NVARCHAR
visit_CLOB, visit_BLOB, visit_DATE
visit_BIT, visit_VARBIT, visit_BYTE, visit_VARBYTE, visit_NIBBLE, visit_GEOMETRY
visit_large_binary -> BLOB
visit_text -> CLOB
visit_datetime -> DATE

Altibase <-> SQLAlchemy <-> Python mapping¶

Altibase Type	SQLAlchemy Type Class (dialect package)	Typical Python value
NUMERIC(p,s)	`NUMERIC`	`decimal.Decimal`
DECIMAL(p,s)	`DECIMAL`	`decimal.Decimal`
FLOAT(p)	`FLOAT`	`float`
REAL	`REAL`	`float`
DOUBLE	`DOUBLE`	`float`
SMALLINT	`SMALLINT`	`int`
INTEGER	`INTEGER`	`int`
BIGINT	`BIGINT`	`int`
SERIAL	`SERIAL`	`int`
VARCHAR(n)	`VARCHAR`	`str`
CHAR(n)	`CHAR`	`str`
NCHAR(n)	`NCHAR`	`str`
NVARCHAR(n)	`NVARCHAR`	`str`
CLOB	`CLOB`	`str`
BLOB	`BLOB`	`bytes`
DATE	`DATE`	`datetime.date` / datetime values from driver
BIT(n)	`BIT`	driver-specific bit representation
VARBIT(n)	`VARBIT`	driver-specific bit representation
BYTE(n)	`BYTE`	`bytes`
VARBYTE(n)	`VARBYTE`	`bytes`
NIBBLE(n)	`NIBBLE`	driver-specific representation
GEOMETRY	`GEOMETRY`	driver-specific geometry object/bytes

Driver-level value representation

For BIT, VARBIT, NIBBLE, and GEOMETRY, exact Python runtime representation depends on pyaltibase behavior.