One, character type
(1) fixed-length string CHAR(byte length is between 1~2000)
CHAR (8) can store 4 double-byte characters, 8 single-byte characters, and less than 8 bytes of the remainder are occupied with spaces
(2) variable-length string VARCHAR2(byte length is between 1~4000)
VARCHAR2 (8) stores the data size as above, less than 8 bytes of the remaining space released
(3) variable length text data LONG(up to 2GB data storage)
Second, the number type
Store integer, floating point, real number, highest precision 38-bit number
Number (10,5) indicates total digits 10 fractional Part 5 (5-bit integer, 5-bit decimal)
Number (n,m) N precision, M-Decimal part
Iii. Date and Time type
(1) Storage date time part accurate to the whole second date
(2) Storage time Date time zone accurate to entire second after 6 bit TIMESTAMP
Four or two binary data
(1) Binary data RAW(up to 2000 bytes in storage)
(2) Large number of binary data Longraw(up to 2GB data storage)
V. unstructured information for large object data type 4GB
(1) Large number of character data CLOB that is Character lob (character lob)
(2) Larger binary objects, shape, video clip, and sound BLOB -binary LOB (binary LOB)
(3) It is used to store binary data in operating system files outside the database BFILE binary file (binary)
Data types for Oracle databases