标签:selector expr select sql sel 选择语句 line 语句 varchar
case选择语句的基本形式:
CASE selector
WHEN expression1 THEN result1
WHEN expression2 THEN result2
WHEN expressionN THEN resultN
[ ELSE resultN+1]
END CASE;
基本的运用
DECLARE
V_grade char(1) := upper(‘&p_grade‘);
V_appraisal varchar2(20);
BEGIN
v_appraisal :=
case v_grade
when ‘A‘ then ‘Excellent‘
when ‘B‘ then ‘Very good‘
when ‘c‘ then ‘good‘
else ‘No such grade‘
end;
dbms_output.put_line(‘grade:‘||v_grade||‘Appraisal: ‘||v_appraisal);
END;
标签:selector expr select sql sel 选择语句 line 语句 varchar
原文地址:http://www.cnblogs.com/w7589/p/7202196.html