Pl/SQL將字符串賦值給一個變量並且每次都打印該值

Question

創建一個名爲'display_player_skill'的函數，該函數接受輸入參數。輸入參數是'player_id'，數字爲數據類型。此函數應返回給定'player_id'的skil_id。

我曾試圖

create or replace function display_player_skill (player_id in number) 
    return varchar2 
is 
    skill_name varchar2(100); 
begin 
    select s.name into skill_name from k_skill s 
    inner join k_player p on p.skill_id=s.id 
    where p.skill_id= player_id; 

    case skill_name 
     when 'Raider' then return 'Player is a Raider'; 
     when 'All rounder' then return 'Player is a All Rounder'; 
    end case; 

exception 
    when case_not_found then return 'Player is a Defender'; 
    when no_data_found then return 'No Such Player'; 
end; 
/

，但我不得不返回skill_id也對給定player_id和顯示skill_name。通過將字符串分配給一個變量並每次打印該值。

Answer 1

似乎where子句不正確（比較skill_id和player_id是很奇怪的）。

where p.skill_id= player_id; 

此外，如果你在k_player有列player_id，甲骨文將把player_id作爲列名。所以，你需要命名參數類似p_player_id（P_的參數）

所以我希望你的代碼看起來是這樣的：

create or replace function display_player_skill (p_player_id in number) 
    return varchar2 
    is 
    skill_name varchar2(100); 
    skill_id number; 
    BEGIN 
    select s.name, s.id into skill_name, skill_id from k_skill s 
    inner join k_player p on p.skill_id=s.id 
    where p.player_id= p_player_id; 

    dbms_output.put_line('Skill name is a '||skill_name); 

    return skill_id; 

EXCEPTION 
when no_data_found then return 'No Such Player'; 
END; 
/

我不知道你的表結構，使一些列名可能需要更正。

Answer 2

嘗試：

select s.name, s.id into skill_name,skill_id from k_skill s 
     inner join k_player p on p.skill_id=s.id 
     where p.player_id= p_player_id; 

    --  dbms_output.put_line('Skill name is a '||skill_name); 

     return skill_id;