SQL nvl等价 - 没有if/case语句&isnull&coalesce

Question

SQL中是否有任何nvl()等效函数？

或者在某些情况下足够接近以相同方式使用的东西？

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更新:
否if语句
没有case语句
no isnull
no coalesce

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select nvl (purge_date,"SODIUFOSDIUFSDOIFUDSF") from id_rec where id=36581;


(expression)

SODIUFOSDIUFSDOIFUDSF

1 row(s) retrieved.

select isnull (purge_date,"SODIUFOSDIUFSDOIFUDSF") from id_rec where id=36581;

  674: Routine (isnull) can not be resolved.
Error in line 1
Near character position 8

select coalesce (purge_date,"SODIUFOSDIUFSDOIFUDSF") from id_rec where id=36581;

  674: Routine (coalesce) can not be resolved.
Error in line 1
Near character position 8

select decode(purge_date, NULL, "01/01/2009", purge_date) from id_rec where id=74115;

  800: Corresponding types must be compatible in CASE expression.
Error in line 1
Near character position 57

Answer 1

ISNULL(单个替换)

要么

COALESCE(返回其参数中的第一个非空表达式.)