Question

我正在编写一个针对内部数据仓库的基本搜索引擎。

假设我拥有＆＃39;技能＆＃39;表，像这样：

EmpID  Skills
-----  --------------------
    1  ,Java,
    2  ,Java,,C#,
    3  ,C#,,Ruby,
    4  ,Java,,C#,,Python,
    5  ,Python,,C#,

我需要编写一个搜索技能表的查询，查找匹配项。

如果我正在搜索Java AND C＃，我希望看到以下结果：

EmpID  Skills             Matches
-----  -----------------  -------
    2  ,Java,,C#,               2
    4  ,Java,,C#,,Python,       2

如果我正在搜索Java OR C＃，我希望看到这些结果，按照匹配排序：

EmpID  Skills              Matches
-----  ------------------  -------
    2  ,Java,,C#,                2
    4  ,Java,,C#,,Python,        2
    1  ,Java,                    1
    3  ,C#,,Ruby,                1
    5  ,Python,,C#,              1

我如何在SQL（Oracle 11）中编写该查询？

谢谢！

Answer 1

with
     test_data ( empid, skills ) as (
       select '1', ',Java,'             from dual union all
       select '2', ',Java,,C#,'         from dual union all
       select '3', ',C#,,Ruby,'         from dual union all
       select '4', ',Java,,C#,,Python,' from dual union all
       select '5', ',Python,,C#,'       from dual
     )
-- end of test data; SOLUTION BEGINS BELOW
select empid, skills, 
       case when skills like '%,Java,%' then 1 else 0 end +
       case when skills like '%,C#,%'   then 1 else 0 end as matches
from test_data
order by matches desc, empid   --  ORDER BY is optional
;

计算Oracle中的匹配项

1 个答案: