Data Type Parameter Description CHAR (N) N = 1 to 2000 byte Delivery string, N-byte length, if the length is not specified, default is 1 byte length (one Chinese word 2 byte) varchar2 (n) N = 1 to 4000 bytes can grow long strings, specify the maximum length N when specifically defined, this data type can put digital, letters, and ASCII code character set (or character set standards such as EBCDIC) All symbols. If the data length does not reach the maximum value n, Oracle 8i automatically adjusts the field length according to the data size. If your data has spaces, Oracle 8i will automatically delete it. VARCHAR2 is the most common data type. The maximum length of the index can be made 3209. Number (m, n) m = 1 to 38n = -84 TO 127 can grow a long value column, allow 0, positive value, and negative value, m is the number of bits of all valid numbers, and n is the number of bits after the decimal point. Such as: Number (5, 2), the maximum value of this field is 99,999, and if the value exceeds the number of digits, the extra number of digits will be intercepted. Such as: Number (5, 2), but in the field of this field input 575.316, the value that is really saved to the field is 575.32. Such as: Number (3, 0), input 575.316, the real saved data is 575. Date does not have all legitimate date from January 1, 4712, 4712, 4712, December 31, 4712, and Oracle 8i actually saved date data internally, in the definition, including hours, minutes, seconds. The default format is DD-MON-YY, such as 07-November -00, represent November 7, 2000. Long unregranted long character columns, the maximum length limit is 2GB, used for long string data for string search, if you want to perform character search, you need to use VARCHAR2 type. Long is an older data type that will gradually be replaced by large object data such as BLOB, Clob, NClob. RAW (n) n = 1 to 2000 variable length binary data, must indicate the maximum length N, Oracle 8i with this format, such as the format, such as the format, such as the format, such as the format, such as Miceosoft Word with this format when the specific definition field is specifically defined. Documentation. RAW is an older data type that will gradually be replaced by large object data such as BLOB, Clob, NClob. Long Raw has no long binary data, the maximum length is 2GB. Oracle 8i uses this format to save large graphics files or text files with formats, such as Miceosoft Word documents, as well as non-text files such as audio, video. In the same table, there is also a long Raw type. Long Raw is also an older data type, which will gradually be replaced by large object data such as BLOB, Clob, NClob. BlobClobnClob has no three large objects (LOB) to save large graphics files or text files with formats, such as Miceosoft Word documents, and audio, video, etc. non-text files, the maximum length is 4GB. There are several types of LOB depends on the type of the byte you use, and Oracle 8i is actually stored in the database inside the database. Special operations such as read, storage, write, etc. can be performed. BFILE is not in the exterior of the database, the maximum length is 4GB. This external LOB type, through the database record, but the specific save of the data is performed outside the database. Oracle 8i can read, query bfile, but cannot be written. The size is determined by the operating system.
