Data types in Oracle

VARCHAR2 (size) variable length character type (maximum character)

NVARCHAR2 (size) variable length unicode character type (maximum character)

char (size) Word length character type (maximum character)

Number (p,s) numeric (p is the maximum length, s is the digit after the decimal point-~)

Data Date Type

CLOB character type for storing single-byte large data objects in a database, up to 4G

NCLOB can hold a large number of Unicode text messages, 4G max.

BLOBs are used to store binary data in a database, such as photos, up to 4G

CLOB and blobs Many operations cannot be done directly using Oracle's database commands,

As a result, Oracle provides a PL/SQL package called Dbms_lob to maintain columns for LOB data types.

bfile external binaries for storing large binary in operating system files outside the database

object, such as movie, Max G. The bfile data type is an external data type and is therefore defined as bfile data

Types of columns cannot be manipulated by Oracle's database commands,

These columns can only be maintained by operating system commands or third-party software.

Raw bare binary data, this type of data occupies a small storage space, operating efficiency is high, but in the network environment

The Oracle server does not perform any character set conversions when transferring data on different computers in the

The raw1-2000 character.

Long, long raw is compatible with previous versions of Oracle, and Oracle continues to support

Long and long raw data types

Long variable character data, max G,long raw bare binary data, Max 2G,

It is primarily used to store unstructured data in a database that was previously 8i.

rowID Line Address

In later versions of Oracle 8, LOB data types can completely replace the Long data type,

and the Oracle server operation LOB data type is more efficient than manipulating the long data type.

In addition, you can define only one column of a Long data type in a table, but you can define multiple LOB data

Type of column. A column of the Long data type can store up to GB of data, whereas a column of the LOB data type can store up to GB of data.

Data types in Oracle