Comparison between MySQL and Oracle common functions and data types

Recently in a turn to the original use of Oracle, the intention to change the MySQL system, some of the common Oracle functions of the MySQL implementation by the way, mainly involved in the system (in fact, the original is specifically collated a detailed doc, only to find word trouble).

Characteristics	Oracle	Mysql
String to date	To_date	Str_to_date
Date type	Date January 1, 4712 BC to December 31, 9999	DateTime: Range of values: +-0100:00:00 to 9999-31 23:59:59 Timestamp: Value range: 1970-01 00:00:00to 2037-31 23:59:59
Date to String	To_char	Date_format
Base64	Utl_raw.cast_to_varchar2 (Utl_encode.base64_encode (Utl_raw.cast_to_raw (' Base64_str ')))	To_base64 (' Base64_str ')
Null value	NVL (col1, ' default value ')	Ifnull (col1, ' 99999999 ')
Logical judgment	Decode (ttype,1, ' a ', 2, ' B ', 3, ' C ', ' d ')	if (ttype=1, ' a ', if (ttype=2, ' B ', if (Ttype =3, ' C ', ' d ')))
Id	Sequence	Auto_increment
Number to String type	To_char ()	Concat (Num_col, ")
String converted to numeric type	To_number ()	Cast (' 1 ' as signed int)
To a microsecond of time	Systimestamp	Sysdate (6)

Comparison between MySQL and Oracle common functions and data types