Data Type (data_type)

A column definition (column_definition) can contain both the column name (column_name) and data types.

The following data types can be distinguished:

?     NULL value

?     Special NULL Value

?     Non-NULL values

Character string, LONG column, Number, Date value, Time value, Timestamp value, BOOLEAN

The non-NULL values can be specified using the syntax element data_type.

Syntax

<data_type> ::=
  
CHAR[ACTER] [(<unsigned_integer>)] [ASCII | BYTE | UNICODE]
|
VARCHAR[(<unsigned_integer>)] [ASCII | BYTE | UNICODE]
|
LONG [VARCHAR] [ASCII | BYTE | UNICODE]
|
BOOLEAN
|
FIXED(<unsigned_integer> [,<unsigned_integer>])
|
FLOAT(<unsigned_integer>)
|
INT[EGER]
|
SMALLINT4
|
DATE | TIME | TIMESTAMP

A code attribute can also be specified for the following character strings (ASCII, BYTE, or UNICODE) as part of a column definition (column_definition) if necessary: CHAR[ACTER], VARCHAR, LONG[VARCHAR]  

Examples

SQL Tutorial, Tables, Number Generator for a Single Column of a Table

Explanation

In addition to the data types defined above, the following data types are also permitted in a column definition. The table below also indicates the way these are mapped to the above-mentioned data types.

Data Type

Is Mapped To

BINARY(p)

FIXED(p)

DEC[IMAL](p,s)

FIXED(p,s)

DEC[IMAL](p)

FIXED(p)

DEC[IMAL]

FIXED(5)

DOUBLE PRECISION

FLOAT(38)

FLOAT

FLOAT(16)

FLOAT(39..64)

FLOAT(38)

LONG VARCHAR

LONG

NUMERIC(p,s)

FIXED(p,s)

NUMERIC(p)

FIXED(p)

NUMERIC

FIXED(5)

REAL(p)

FLOAT(p)

REAL

FLOAT(16)

SERIAL

FIXED(10) DEFAULT SERIAL

SERIAL(p)

FIXED(10) DEFAULT SERIAL(p)

See also:

Memory Requirements of a Column Value According to Data Type

SQL Tutorial, Converting Values