在下面的表中显示了常用的内置数据类型。

表 1. Data Types
Name Alias Description
BLOB LONG RAW, RAW(n), BYTEA Binary data
BOOLEAN Logical Boolean (true/false)
CHAR [ (n) ] CHARACTER [ (n) ] Fixed-length character string of n characters
CLOB LONG, LONG VARCHAR Long character string
DATE TIMESTAMP(0) Date and time to the second
DOUBLE PRECISION FLOAT, FLOAT(25) - FLOAT(53) Double precision floating-point number
INTEGER INT, BINARY INTEGER, PLS INTEGER Signed four-byte integer
NUMBER DEC, DECIMAL, NUMERIC Exact numeric with optional decimal places
NUMBER(p [, s ]) DEC(p [, s ]), DECIMAL(p [, s ]), NUMERIC(p [, s ]) Exact numeric of maximum precision, p, and optional scale, s
REAL FLOAT(1) - FLOAT(24) Single precision floating-point number
TIMESTAMP [ (p) ] Date and time with optional, fractional second precision, p
TIMESTAMP [ (p) ] WITH TIME ZONE Date and time with optional, fractional second precision, p, and with time zone
VARCHAR2(n) CHAR VARYING(n), CHARACTER VARYING(n), VARCHAR(n) Variable-length character string with a maximum length of n characters
XMLTYPE XML data

在下面的章节中会详细介绍了每一种数据类型。