Oracle常用功能函数汇总.docVIP

oracle 常用功能函数汇总 ******************************************************************************* * SQL Group Functions (num can be a column or expression) * (null values are ignored, default between distinct and all is all) * ******************************************************************************* AVG([distinct or all] num) -- average value COUNT(distinct or all] num) -- number of values MAX([distinct or all] num) -- maximum value MIN([distinct or all] num) -- minimum value STDDEV([distinct or all] num) -- standard deviation SUM([distinct or all] num) -- sum of values VARIANCE([distinct or all] num) -- variance of values ******************************************************************************* * Miscellaneaous Functions : * ******************************************************************************* DECODE(expr, srch1, return1 [,srch2, return2...], default] -- if no search matches the expression then the default is returned, -- otherwise, the first search that matches will cause -- the corresponding return value to be returned DUMP(column_name [,fmt [,start_pos [, length]]]) -- returns an internal oracle format, used for getting info about a column -- format options : 8 = octal, 10 = decimel, 16 = hex, 17 = characters -- return type codes : 1 = varchar2, 2 = number, 8 = long, 12 = date, -- 23 = raw, 24 = long raw, 69 = rowid, 96 = char, 106 = mlslabel GREATEST(expr [,expr2 [, expr3...]] -- returns the largest value of all expressions LEAST(expr [,expr2 [, expr3...]] -- returns the smallest value of all expressions NVL(expr1 ,expr2 -- if expr1 is not null, it is returned, otherwise expr2 is returned SQLCODE -- returns sql error code of last error. Can not be used directly in query, -- value must be set to local variable first SQLERRM