Question

我是Oracle的新手并且了解MS SQL。我正在尝试根据user_id中的Table2获取电话号码，这是业务逻辑：

案例1：如果在Table1中找到一个匹配项，则从Table2
案例2：如果在Table1中找不到匹配项，则从Table2
案例3：如果在Table1中找到多个匹配，那么对于所有assigned_care_levels Care，请Table2按asc排序desc或ERROR: ORA-00907: missing right parenthesis并选择顶行电话号码。

我编写了以下查询，当我单独运行它时，它可以正常工作。但是，当我使用if else语句进行cobine时，我收到以下错误if ((select count(distinct care_level) from Table1 where user_id = '100') > 0) select phone from Table2 where care_level in (select distinct care_level from Table1 where user_id = '100') and rownum = 1 order by care_level asc else if((select count(distinct care_level) from Table1 where user_id = '100') = 0) select phone from Table2 where care_level = 'default'。这是我的代码：

{{1}}

Answer 1

SET SERVEROUTPUT ON;

DECLARE
       v_CARE_COUNT NUMBER := 0;
       v_PHONE VARCHAr2(40) := NULL;
BEGIN
      select  count(distinct care_level) 
         into v_CARE_COUNT
      from Table1 
       where user_id = '100';

      IF(v_CARE_COUNT > 0) THEN

         select phone into v_PHONE 
         from Table2 
         where care_level in 
           (select distinct care_level from Table1 where user_id = '100')
         and rownum = 1;
      ELSE
         select phone into v_PHONE
          from Table2
         where care_level = 'default';
      END IF;
      DBMS_OUTPUT.PUT_LINE('PHONE is <'||v_PHONE||'>');
 EXCEPTION
 WHEN OTHERS THEN
      DBMS_OUTPUT.PUT_LINE('Exception : '||SQLERRM);
 END;
 /

编辑：（AS SIngle SQL）

 SELECT PHONE 
 FROM TABLE2
 WHERE CARE_LEVEL in
       (
          SELECT CARE_LEVEL FROM TABLE1 WHERE USER_ID='100'
           UNION
          SELECT CARE_LEVEL FROM TABLE1 WHERE CARE_LEVEL='default'
            AND NOT EXISTS
              (SELECT 'X' FROM TABLE1 WHERE USER_ID='100')
        )
 AND ROWNUM = 1;

Answer 2

'else if'语法错误。在Oracle中，您需要使用'ELSIF'并使用'END IF'完成整个条件语句。其中的SQL语句也应该跟一个;

尝试：

IF ((select count(distinct care_level) from Table1 where user_id = '100') > 0) THEN
    select phone from Table2 where care_level in (select distinct care_level from Table1 where user_id = '100')
    and rownum = 1 
    order by care_level asc;
ELSIF ((select count(distinct care_level) from Table1 where user_id = '100') = 0) THEN
    select phone from Table2 where care_level = 'default'; END IF

使用if else阻止错过右括号错误

2 个答案: