求教 语句,急!!!!!!!!

Question

有的，语法有两种：
a.CASE语句 
   CASE selector
   WHEN expression1 THEN sequence_of_statements1;
   WHEN expression2 THEN sequence_of_statements2;
   .......
   WHEN expressionN THEN sequence_of_statementsN;
   [ELSE sequence_of_statementsN+1;]
   END CASE
b.CASE表达式
   CASE 
   WHEN search_condition1 THEN sequence_of_statements1;
   WHEN search_condition2 THEN sequence_of_statements2;
   .......
   WHEN search_conditionN THEN sequence_of_statementsN;
   [ELSE sequence_of_statementsN+1;]
   END CASE

Answer 1

有 
 CASE selector
   WHEN expression1 THEN sequence_of_statements1;
   WHEN expression2 THEN sequence_of_statements2;
   .......
   WHEN expressionN THEN sequence_of_statementsN;
   [ELSE sequence_of_statementsN+1;]
END CASE