Oracle single row function classification

Oracle single row function classification single row function is mainly divided into five types: character (VARCHAR2) function, NUMBER function, DATE function,
The conversion function www.2cto.com is mainly used to operate string data, for example :. UPPER (string and column): converts the input string into uppercase and returns the result ;. LOWER (string and column): converts the input string to lowercase and returns the result ;. INITCAP (string and column): upper-case letters at the beginning ;. LENGTH (string, column): returns the LENGTH of the string ;. REPLACE (string, column): REPLACE ;. SUBSTR (string, column, start point [, end point]): String truncation; Numeric functions such :. ROUND (number and column [Reserved decimal digits]): rounding operation ;. TRUNC (number, column): discard the content at the specified position ;. MOD (number 1, number 2); modulo, take the remainder www.2cto.com date function to get the current date: sysdate Java code select sysdate from dual ;. LAST_DAY (). NEXT_DAT (date, number of weeks ). AD D_MONTHS (date, number ). MONTHS_BETWEEN (date 1, date 2) Conversion Function. TO_CHAR (string | column, Format String): converts a date or number into a string for display. TO_DATE (string, Format String); Convert string to DATE data display. TO_NUMBER (string): converts a string to a number for display. Java code select TO_CHAR (sysdate, 'yyyy-mm-dd'), TO_CHAR (sysdate, 'yyyy') from dual Java code select TO_CHAR (sysdate, 'fmyyyy-mm-dd'), TO_CHAR (sysdate, 'yyyy') from dual remove leading date 0; Java code select TO_CHAR (sysdate, 'hh24'), TO_CHAR (sysdate, 'hh-mi-ss') from dual number formatting Java code select TO_CHAR (1222223, '000000') from dual currency Java code select TO_CHAR (999,999,999, 'l999, 100 ') from dual L (locale :. NVL () function, processing NULL Java code select NVL (money, 0) from demo ;. DECODE () function: multi-value judgment Java code decode (column, judgment value 1, display value 1, judgment value 2, display value 2)