Oracle table Field Data Type

Varchar2 ()	Storage character, variable length, maximum length, maximum 4000 bytes
Number	Store numbers
Date	Storage date
Char ()	Storage character, fixed length (if a data is shorter than the definition length, the space will be added to the right of the data to define the length), maximum length, maximum 2000 bytes
Long	Is a legacy data type that will not be supported in the future. It will be replaced by the lob (large object) data type.
Longraw
Raw
Rowid	A pseudo column in an ORACLE data table, which is the unique identifier of each row of data in the data table.
Float
Integer
Nchar ()	Same as char (), stores NLS data
Nvarchar2	Same as varchar2 (), which stores NLS data
Blob	Store binary data
Clob	Store structured data
Nclob
Bfile	Store binary files
Urowid
Timestamp
Timestamp with Time Zone
Timestamp with local time zone
Interval year to month
Interval day to second
Binary_float
Binary_double

Notes
I. Comparison rules:

Char () Data Type	'Yo' = 'yo'
Varchar2 () Data Type	'Yo' <'yo'