A.to_char函數(shù)是將字符串?dāng)?shù)據(jù)轉(zhuǎn)換為日期數(shù)據(jù) B.to_date函數(shù)是將字符串?dāng)?shù)據(jù)轉(zhuǎn)換為日期數(shù)據(jù) C.to_char函數(shù)是將日期數(shù)據(jù)轉(zhuǎn)換為字符數(shù)據(jù) D.to_date函數(shù)是將日期數(shù)據(jù)轉(zhuǎn)換為字符數(shù)據(jù)
A.SELECT.TO_CHAR(1890.55,’$0G000D00’)FROMDUAL B.SELECT.TO_CHAR(1890.55,’$9,999V99’)FROMDUAL C.SELECT.TO_CHAR(1890.55,’$99,999D99’)FROMDUAL D.SELECT.TO_CHAR(1890.55,’$99G999D00’)FROMDUAL E.SELECT.TO_CHAR(1890.55,’$99G999D99’)FROMDUAL
A.他們只能接受一個(gè)參數(shù) B.他們只能嵌套兩層 C.參數(shù)只能是字段值或常量 D.他們始終為查找表中的每個(gè)行返回一個(gè)值