Oracle is judged using Case...when statements.

Use the Case...when statement to determine its syntax in the following format:

Case<selector>

When<expression_1> then pl_sqlsentence_1;

When<expression_2> then pl_sqlsentence_2;

...

When<expression_n> then Pl_sqlsentence_n;

[Else plsql_sentence;]

End case;

Specific examples are as follows:

DeclareV_seasonint:=3; Autoinfovarchar2( -);begin   CaseV_season when 1  ThenAutoinfo:=V_season||'season includes 1, 2, March';  when 2  ThenAutoinfo:=V_season||'season includes 4, 5, June';  when 3  ThenAutoinfo:=V_season||'season includes 7, 8, September';  when 4  ThenAutoinfo:=V_season||'season includes 10, 11, December'; ElseAutoinfo:=V_season||'The seasons are illegal .'; End  Case; Dbms_output.put_line (autoinfo);End;

Output Result:

3 seasons including 7,8,9 month

In the use of case...when, only need to write a case on OK, can not write more than one, the wrong wording as follows:

DeclareV_seasonint:=3; Autoinfovarchar2( -);begin   CaseV_season when 1  ThenAutoinfo:=V_season||'season includes 1, 2, March';  CaseV_season when 2  ThenAutoinfo:=V_season||'season includes 4, 5, June';  CaseV_season when 3  ThenAutoinfo:=V_season||'season includes 7, 8, September';  CaseV_season when 4  ThenAutoinfo:=V_season||'season includes 10, 11, December'; ElseAutoinfo:=V_season||'The seasons are illegal .'; End  Case; Dbms_output.put_line (autoinfo);End;

If this is the case, the syntax is wrong and an error occurs when you run the PL/SQL block.

Oracle is judged with case...when statements