SQL，PL/SQL 数据类型一览表

Data Type Syntax

Oracle 9i

Oracle 10g

Oracle 11g

Explanation
(if applicable)

char(size)

Maximum size of 2000 bytes.

Maximum size of 2000 bytes.

Maximum size of 2000 bytes.

Where size is the number of characters to store. Fixed-length strings. Space padded.

nchar(size)

Maximum size of 2000 bytes.

Maximum size of 2000 bytes.

Maximum size of 2000 bytes.

Where size is the number of characters to store. Fixed-length NLS string Space padded.

nvarchar2(size)

Maximum size of 4000 bytes.

Maximum size of 4000 bytes.

Maximum size of 4000 bytes.

Where size is the number of characters to store. Variable-length NLS string.

varchar2(size)

Maximum size of 4000 bytes.

Maximum size of 4000 bytes.

Maximum size of 4000 bytes.

Where size is the number of characters to store. Variable-length string.

long

Maximum size of 2GB.

Maximum size of 2GB.

Maximum size of 2GB.

Variable-length strings. (backward compatible)

raw

Maximum size of 2000 bytes.

Maximum size of 2000 bytes.

Maximum size of 2000 bytes.

Variable-length binary strings

long raw

Maximum size of 2GB.

Maximum size of 2GB.

Maximum size of 2GB.

Variable-length binary strings. (backward compatible)

Data Type Syntax

Oracle 9i

Oracle 10g

Oracle 11g

Explanation
(if applicable)

number(p,s)

Precision can range from 1 to 38.
Scale can range from -84 to 127.

Precision can range from 1 to 38.
Scale can range from -84 to 127.

Precision can range from 1 to 38.
Scale can range from -84 to 127.

Where p is the precision and s is the scale.

For example, number(7,2) is a number that has 5 digits before the decimal and 2 digits after the decimal.

numeric(p,s)

Precision can range from 1 to 38.

Precision can range from 1 to 38.

Precision can range from 1 to 38.

Where p is the precision and s is the scale.

For example, numeric(7,2) is a number that has 5 digits before the decimal and 2 digits after the decimal.

float

dec(p,s)

Precision can range from 1 to 38.

Precision can range from 1 to 38.

Precision can range from 1 to 38.

Where p is the precision and s is the scale.

For example, dec(3,1) is a number that has 2 digits before the decimal and 1 digit after the decimal.

decimal(p,s)

Precision can range from 1 to 38.

Precision can range from 1 to 38.

Precision can range from 1 to 38.

Where p is the precision and s is the scale.

For example, decimal(3,1) is a number that has 2 digits before the decimal and 1 digit after the decimal.

integer

int

smallint

real

double precision

Data Type Syntax

Oracle 9i

Oracle 10g

Oracle 11g

Explanation
(if applicable)

date

A date between Jan 1, 4712 BC and Dec 31, 9999 AD.

A date between Jan 1, 4712 BC and Dec 31, 9999 AD.

A date between Jan 1, 4712 BC and Dec 31, 9999 AD.

timestamp (fractional seconds precision)

fractional seconds precision must be a number between 0 and 9. (default is 6)

fractional seconds precision must be a number between 0 and 9. (default is 6)

fractional seconds precision must be a number between 0 and 9. (default is 6)

Includes year, month, day, hour, minute, and seconds.

For example:
timestamp(6)

timestamp (fractional seconds precision) with time zone

fractional seconds precision must be a number between 0 and 9. (default is 6)

fractional seconds precision must be a number between 0 and 9. (default is 6)

fractional seconds precision must be a number between 0 and 9. (default is 6)

Includes year, month, day, hour, minute, and seconds; with a time zone displacement value.

For example:
timestamp(5) with time zone

timestamp (fractional seconds precision) with local time zone

fractional seconds precision must be a number between 0 and 9. (default is 6)

fractional seconds precision must be a number between 0 and 9. (default is 6)

fractional seconds precision must be a number between 0 and 9. (default is 6)

Includes year, month, day, hour, minute, and seconds; with a time zone expressed as the session time zone.

For example:
timestamp(4) with local time zone

interval year
(year precision)
to month

year precision is the number of digits in the year. (default is 2)

year precision is the number of digits in the year. (default is 2)

year precision is the number of digits in the year. (default is 2)

Time period stored in years and months.

For example:
interval year(4) to month

interval day
(day precision)
to second (fractional seconds precision)

day precision must be a number between 0 and 9. (default is 2)

fractional seconds precision must be a number between 0 and 9. (default is 6)

day precision must be a number between 0 and 9. (default is 2)

fractional seconds precision must be a number between 0 and 9. (default is 6)

day precision must be a number between 0 and 9. (default is 2)

fractional seconds precision must be a number between 0 and 9. (default is 6)

Time period stored in days, hours, minutes, and seconds.

For example:
interval day(2) to second(6)

Data Type Syntax

Oracle 9i

Oracle 10g

Oracle 11g

Explanation
(if applicable)

bfile

Maximum file size of 4GB.

Maximum file size of 2³²-1 bytes.

Maximum file size of 2⁶⁴-1 bytes.

File locators that point to a binary file on the server file system (outside the database).

blob

Store up to 4GB of binary data.

Store up to (4 gigabytes -1) * (the value of the CHUNK parameter of LOB storage).

Store up to (4 gigabytes -1) * (the value of the CHUNK parameter of LOB storage).

Stores unstructured binary large objects.

clob

Store up to 4GB of character data.

Store up to (4 gigabytes -1) * (the value of the CHUNK parameter of LOB storage) of character data.

Store up to (4 gigabytes -1) * (the value of the CHUNK parameter of LOB storage) of character data.

Stores single-byte and multi-byte character data.

nclob

Store up to 4GB of character text data.

Store up to (4 gigabytes -1) * (the value of the CHUNK parameter of LOB storage) of character text data.

Store up to (4 gigabytes -1) * (the value of the CHUNK parameter of LOB storage) of character text data.

Stores unicode data.

Data Type Syntax

Oracle 9i

Oracle 10g

Oracle 11g

Explanation
(if applicable)

rowid

The format of the rowid is: BBBBBBB.RRRR.FFFFF

Where BBBBBBB is the block in the database file;
RRRR is the row in the block;
FFFFF is the database file.

The format of the rowid is: BBBBBBB.RRRR.FFFFF

Where BBBBBBB is the block in the database file;
RRRR is the row in the block;
FFFFF is the database file.

The format of the rowid is: BBBBBBB.RRRR.FFFFF

Where BBBBBBB is the block in the database file;
RRRR is the row in the block;
FFFFF is the database file.

Fixed-length binary data. Every record in the database has a physical address or rowid.

urowid(size)

Universal rowid.

Where size is optional