72.Which tasks can be performed using SQL functions built into Oracle Database ? (Choose three.)

72.Which tasks can be performed using SQL functions built into Oracle Database ? (Choose three.)
A.displaying a date in a nondefault format
B.finding the number of characters in an expression
C.substituting a character string in a text expression with a specified string
D.combining more than two columns or expressions into a single column in the output
答案：ABC
解析：那个可以使用oracle内置函数来完成
A:非默认格式显示日期，to_char
B:一个表达式的字符数，length
C:用指定的字符串替换子串，replace
D:连接多余两列，contack只能连接一列