Oracle sql 添加自定义列名作为结果集的第一行

Question

如何将列名作为结果的第一行 set.I 在下面尝试过但得到如下所示的错误

select 'First Name', 'Last Name', 'Middle Name', 'Term Number', 'BID', 'BTitle', 'SubB Name', 'LNum' from dual 
    UNION
    select
                pa.first_name as first_name,
                pa.last_name as last_name,
                pa.MIDDLE_INITIAL as middle_name,
                bi.bi_num as num,
                bi.b_id as bId,
                b.name as b_title,
                bi.sub_board_name as sub_b_name,         
                pa.L_NUMBER as lNum
            from
                M_INFO pa,
                B_INV bi,
                Blot b,
                users u,
                roles r  
            where
                bi.assigned_to  = u.bi_num(+) 
                and bi.bi_num = pa.bi_num(+) 
                and u.role_id = r.id(+)  
                and bi.b_id = b.id
                and bi.delete_dt is null  
                and bi.delete_by is null  
                and bi.ARCHIVED_DT is null  
                and bi.b_id = '40'  and bi.sub_b_name = 'TEST'; 


ORA-01790: expression must have same datatype as corresponding expression
01790. 00000 -  "expression must have same datatype as corresponding expression"
*Cause:    
*Action:
Error at Line: 1 Column: 50

Answer 1

我建议对您的查询进行两处更改。

将 UNION 更改为 UNION ALL。这样你的联合就不会在联合的两个部分之间寻找重复项。
由于联合的第一部分都是字符串，因此联合的第二部分也需要 return 所有字符串。并集第二部分中的任何数字列都需要转换为字符串。示例：将 bi.bi_num 更改为 TO_CHAR(bi.bi_num)

Oracle sql 添加自定义列名作为结果集的第一行

Oracle sql adding custom column name as 1st row of the resultSet

sql

oracle

oracle11g