Question

可能重复：
Include a blank row in query results

我想在SQL查询的最顶层为我的结果集添加一个空行。

我使用的查询是：

SELECT 
    PROFILETITLE, DOCID 
FROM
    PROFILES
WHERE 
    COMPANYCODE = ? 
ORDER BY 
    PROFILETITLE

Answer 1

尝试使用union all

SELECT null as PROFILETITLE, null as DOCID 
UNION ALL
SELECT PROFILETITLE, DOCID 
FROM PROFILES
WHERE COMPANYCODE=? 
ORDER BY PROFILETITLE

但如果你不想添加标题，如果DOCID是int类型，则必须使用union all和cast，如下所示

SELECT 'PROFILETITLE' as PROFILETITLE, 'DOCID' as DOCID 
UNION ALL
SELECT PROFILETITLE, CAST ( DOCID AS varchar(30) )
FROM PROFILES
WHERE COMPANYCODE=? 
ORDER BY PROFILETITLE

Answer 2

试试这个：

SELECT '' AS PROFILETITLE, 0 AS DOCID
UNION ALL
SELECT PROFILETITLE, DOCID
FROM PROFILES WHERE COMPANYCODE = ? 
ORDER BY PROFILETITLE

请注意，在使用UNION和所有其他设置操作时，列必须在类型中匹配，因此您必须使用PROFILETITLE和DOCID将前两个空值设为别名。而且你必须注意两列的类型以及匹配才能正常工作。您可能需要选择NULL而不是''和0。

Answer 3

如果所有列都为varchar，则可以添加“空行”，以这种方式为空，表示''：

SELECT PROFILETITLE, DOCID 
FROM PROFILES
WHERE ...

UNION ALL

SELECT '' AS PROFILETITLE, '' AS DOCID

ORDER BY 
  CASE WHEN PROFILETITLE='' AND DOCID='' THEN 0 ELSE 1 END ASC
, PROFILETITLE ASC

Answer 4

您可以使用SQL Union

SELECT PROFILETITLE, DOCID 
FROM PROFILES
WHERE COMPANYCODE=? ORDER BY PROFILETITLE
UNION ALL
SELECT 0, '' 
FROM SYSIBM.SYSDUMMY1

您可以将SYSIBM.SYSDUMMY1替换为临时表

Answer 5

工会全部都可以胜任

SELECT 
'' as PROFILETITLE,
'' as DOCID
UNION ALL
SELECT PROFILETITLE, DOCID 
FROM PROFILES
WHERE COMPANYCODE=? ORDER BY PROFILETITLE

选择不存在的其他空行

5 个答案: