참조 : Database SQL Language Reference

1. character_datatypes (문자열)

{ CHAR [ (size [ BYTE | CHAR ]) ]
| VARCHAR2 (size [ BYTE | CHAR ])
| NCHAR [ (size) ]
| NVARCHAR2 (size)
}

2. number_datatypes (숫자형)

{ NUMBER [ (precision [, scale ]) ]
| FLOAT [ (precision) ]
| BINARY_FLOAT
| BINARY_DOUBLE
}

1) NUMBER Data Type

NUMBER(p,s)
NUMBER(p) -> NUMBER(p,0)
NUMBER  -> NUMBER(38,0)

정밀도 p
1부터 38값을 가지고, 기본 38이다.
숫자의 자릿수를 의미한다.

스케일 s
-84 부터 127의 값을 가지고 기본 0이다.
소수점 아래 자릿수를 의미한다.

사용 예시)

Actual Data	Specified As	Stored As
123.89	NUMBER	123.89
123.89	NUMBER(3)	124
123.89	NUMBER(3,2)	exceeds precision
123.89	NUMBER(4,2)	exceeds precision
123.89	NUMBER(5,2)	123.89
123.89	NUMBER(6,1)	123.9
123.89	NUMBER(6,-2)	100
.01234	NUMBER(4,5)	.01234
.00012	NUMBER(4,5)	.00012
.000127	NUMBER(4,5)	.00013
.0000012	NUMBER(2,7)	.0000012
.00000123	NUMBER(2,7)	.0000012
1.2e-4	NUMBER(2,5)	0.00012
1.2e-5	NUMBER(2,5)	0.00001

2) FLOAT Data Type

CREATE TABLE test (col1 NUMBER(5,2), col2 FLOAT(5));

INSERT INTO test VALUES (1.23, 1.23);
INSERT INTO test VALUES (7.89, 7.89);
INSERT INTO test VALUES (12.79, 12.79);
INSERT INTO test VALUES (123.45, 123.45);

SELECT * FROM test;

      COL1       COL2
---------- ----------
      1.23        1.2
      7.89        7.9
     12.79         13
    123.45        120

3. datetime_datatypes (날짜형)

Datetime Field	Valid Values for Datetime	Valid Values for INTERVAL
YEAR	-4712 to 9999 (excluding year 0)	Any positive or negative integer
MONTH	01 to 12	0 to 11
DAY	01 to 31 (limited by the values of MONTH and YEAR, according to the rules of the current NLS calendar parameter)	Any positive or negative integer
HOUR	00 to 23	0 to 23
MINUTE	00 to 59	0 to 59
SECOND	00 to 59.9(n), where 9(n) is the precision of time fractional seconds. The 9(n) portion is not applicable for DATE.	0 to 59.9(n), where 9(n) is the precision of interval fractional seconds
TIMEZONE_HOUR	-12 to 14 (This range accommodates daylight saving time changes.) Not applicable for DATE or TIMESTAMP.	Not applicable
TIMEZONE_MINUTE (See note at end of table)	00 to 59. Not applicable for DATE or TIMESTAMP.	Not applicable
TIMEZONE_REGION	Query the TZNAME column of the V$TIMEZONE_NAMES data dictionary view. Not applicable for DATE or TIMESTAMP. For a complete listing of all time zone region names, refer to Oracle Database Globalization Support Guide.	Not applicable
TIMEZONE_ABBR	Query the TZABBREV column of the V$TIMEZONE_NAMES data dictionary view. Not applicable for DATE or TIMESTAMP.	Not applicable

전체 표

Code	Data Type	Description	설명
1	VARCHAR2(size [BYTE | CHAR])	Variable-length character string having maximum length size bytes or characters. You must specify size for VARCHAR2. Minimum size is 1 byte or 1 character. Maximum size is: 32767 bytes or characters if MAX_STRING_SIZE = EXTENDED 4000 bytes or characters if MAX_STRING_SIZE = STANDARD   Refer to "Extended Data Types" for more information on the MAX_STRING_SIZE initialization parameter. BYTE indicates that the column will have byte length semantics. CHAR indicates that the column will have character semantics.	가변길이 문자열 byte 기준 사이즈
1	NVARCHAR2(size)	Variable-length Unicode character string having maximum length size characters. You must specify size for NVARCHAR2. The number of bytes can be up to two times size for AL16UTF16 encoding and three times size for UTF8 encoding. Maximum size is determined by the national character set definition, with an upper limit of: 32767 bytes if MAX_STRING_SIZE = EXTENDED 4000 bytes if MAX_STRING_SIZE = STANDARD   Refer to "Extended Data Types" for more information on the MAX_STRING_SIZE initialization parameter.	가변길이 문자열 Unicode 기준 사이즈
2	NUMBER [ (p [, s]) ]	Number having precision p and scale s. The precision p can range from 1 to 38. The scale s can range from -84 to 127. Both precision and scale are in decimal digits. A NUMBER value requires from 1 to 22 bytes.	숫자형 데이터 p는 정밀도로 기본 38다. 최소 1 한자리수 부터, 최대 38 자리수까지 s는 스케일값으로 기본 0이다, 소숫점 아래 표현 수 이다. 데이터 사이즈는 1 부터 22 bytes이다.
2	FLOAT [(p)]	A subtype of the NUMBER data type having precision p. A FLOAT value is represented internally as NUMBER. The precision p can range from 1 to 126 binary digits. A FLOAT value requires from 1 to 22 bytes.	실수형 데이터 타입 p는 NUMBER와 같은 스케일 값이다. 데이터 사이즈는 1부터 22bytes이다,
8	LONG	Character data of variable length up to 2 gigabytes, or 2^31 -1 bytes. Provided for backward compatibility.	문자형 데이터로 길이는 최대 2gb거나 2^31 - 1 btres이다.
12	DATE	Valid date range from January 1, 4712 BC, to December 31, 9999 AD. The default format is determined explicitly by the NLS_DATE_FORMAT parameter or implicitly by the NLS_TERRITORY parameter. The size is fixed at 7 bytes. This data type contains the datetime fields YEAR, MONTH, DAY, HOUR, MINUTE, and SECOND. It does not have fractional seconds or a time zone.	날짜형 데이터
100	BINARY_FLOAT	32-bit floating point number. This data type requires 4 bytes.	32bit 이진수 데이터
101	BINARY_DOUBLE	64-bit floating point number. This data type requires 8 bytes.	64bit 이진수 데이터
180	TIMESTAMP [(fractional_seconds_precision)]	Year, month, and day values of date, as well as hour, minute, and second values of time, where fractional_seconds_precision is the number of digits in the fractional part of the SECOND datetime field. Accepted values of fractional_seconds_precision are 0 to 9. The default is 6. The default format is determined explicitly by the NLS_TIMESTAMP_FORMAT parameter or implicitly by the NLS_TERRITORY parameter. The size is 7 or 11 bytes, depending on the precision. This data type contains the datetime fields YEAR, MONTH, DAY, HOUR, MINUTE, and SECOND. It contains fractional seconds but does not have a time zone.
181	TIMESTAMP [(fractional_seconds_precision)] WITH TIME ZONE	All values of TIMESTAMP as well as time zone displacement value, where fractional_seconds_precision is the number of digits in the fractional part of the SECOND datetime field. Accepted values are 0 to 9. The default is 6. The default format is determined explicitly by the NLS_TIMESTAMP_FORMAT parameter or implicitly by the NLS_TERRITORY parameter. The size is fixed at 13 bytes. This data type contains the datetime fields YEAR, MONTH, DAY, HOUR, MINUTE, SECOND, TIMEZONE_HOUR, and TIMEZONE_MINUTE. It has fractional seconds and an explicit time zone.
231	TIMESTAMP [(fractional_seconds_precision)] WITH LOCAL TIME ZONE	All values of TIMESTAMP WITH TIME ZONE, with the following exceptions: Data is normalized to the database time zone when it is stored in the database. When the data is retrieved, users see the data in the session time zone.   The default format is determined explicitly by the NLS_TIMESTAMP_FORMAT parameter or implicitly by the NLS_TERRITORY parameter. The size is 7 or 11 bytes, depending on the precision.
182	INTERVAL YEAR [(year_precision)] TO MONTH	Stores a period of time in years and months, where year_precision is the number of digits in the YEAR datetime field. Accepted values are 0 to 9. The default is 2. The size is fixed at 5 bytes.
183	INTERVAL DAY [(day_precision)] TO SECOND [(fractional_seconds_precision)]	Stores a period of time in days, hours, minutes, and seconds, where day_precision is the maximum number of digits in the DAY datetime field. Accepted values are 0 to 9. The default is 2. fractional_seconds_precision is the number of digits in the fractional part of the SECOND field. Accepted values are 0 to 9. The default is 6.   The size is fixed at 11 bytes.
23	RAW(size)	Raw binary data of length size bytes. You must specify size for a RAW value. Maximum size is: 32767 bytes if MAX_STRING_SIZE = EXTENDED 2000 bytes if MAX_STRING_SIZE = STANDARD   Refer to "Extended Data Types" for more information on the MAX_STRING_SIZE initialization parameter.
24	LONG RAW	Raw binary data of variable length up to 2 gigabytes.
69	ROWID	Base 64 string representing the unique address of a row in its table. This data type is primarily for values returned by the ROWID pseudocolumn.
208	UROWID [(size)]	Base 64 string representing the logical address of a row of an index-organized table. The optional size is the size of a column of type UROWID. The maximum size and default is 4000 bytes.
96	CHAR [(size [BYTE | CHAR])]	Fixed-length character data of length size bytes or characters. Maximum size is 2000 bytes or characters. Default and minimum size is 1 byte. BYTE and CHAR have the same semantics as for VARCHAR2.	고정길이 문자열 byte 기준 사이즈
96	NCHAR[(size)]	Fixed-length character data of length size characters. The number of bytes can be up to two times size for AL16UTF16 encoding and three times size for UTF8 encoding. Maximum size is determined by the national character set definition, with an upper limit of 2000 bytes. Default and minimum size is 1 character.	고정길이  문자열 unicode 기준 문자열
112	CLOB	A character large object containing single-byte or multibyte characters. Both fixed-width and variable-width character sets are supported, both using the database character set. Maximum size is (4 gigabytes - 1) * (database block size).
112	NCLOB	A character large object containing Unicode characters. Both fixed-width and variable-width character sets are supported, both using the database national character set. Maximum size is (4 gigabytes - 1) * (database block size). Stores national character set data.
113	BLOB	A binary large object. Maximum size is (4 gigabytes - 1) * (database block size).
114	BFILE	Contains a locator to a large binary file stored outside the database. Enables byte stream I/O access to external LOBs residing on the database server. Maximum size is 4 gigabytes.