Oracle in If/else

1. Standard SQL specification

One, single IF1, if A=  ... Then.........end if;2, if a= ... then......else....end if; two, more IfIf a=.  Then......elsif a=.  Then....end if;     The middle here is "elsif", not else IF. Special attention is needed here.

2. Decode function

syntax for decode :

DECODE (Value,if1,then1,if2,then2,if3,then3,..., else)

Indicates that if value equals IF1, the result of the Decode function returns THEN1,..., if it is not equal to any one if value, else is returned.

3. Case

Case when a= ' 1 ' and ' xxxx ' when     a= ' 2 ' then ' ssss ' else
' Zzzzz ' End as

Note the point:

1. Start with case and end With end
2. When the branch is followed by the condition, then the result is displayed
3, else in addition to the default, similar to the high-level language program switch case default, you can not add
4, END followed by alias

Category: Db-oracle

Oracle in If/else