如何将查询结果转换为字符串并将其插入表行

Posted 2023-05-08

【中文标题】如何将查询结果转换为字符串并将其插入表行

【英文标题】：How can I cast a query result to string and insert it into a table row

【发布时间】：2019-04-05 06:59:27

【问题描述】：

我收到一个错误，即子查询返回多个值，我知道它会这样做，现在我想将该子查询结果转换为一个字符串，然后将该字符串插入到同一位置的表中

我已经尝试过使用循环，但由于除了查询之外我不能在其他任何地方使用循环，它并没有多大帮助。

这是我正在处理的查询

SELECT DISTINCT LiveCampaign_SubscriberList_Email.Email, Firstname, Lastname, dbo.spValueToString(Subscribed) AS Subscribed,

dbo.spValueToString((SELECT COUNT(*) 
    FROM tblEmailBlackList
    WHERE tblEmailBlackList.Email = LiveCampaign_SubscriberList_Email.Email and tblEmailBlackList.PortalID = -2)) As GeneralBlockList,

(SELECT DISTINCT PortalLocalization.PortalName
    FROM tblEmailBlackList
    LEFT JOIN tblLiveCampaignSettings ON tblLiveCampaignSettings.ModuleID = tblEmailBlackList.ModuleID
    LEFT JOIN PortalLocalization ON PortalLocalization.PortalID = tblEmailBlackList.PortalID AND PortalLocalization.CultureCode = 'sl-SI'
    LEFT JOIN #tmp ON tblEmailBlackList.Email = #tmp.Email COLLATE Slovenian_CI_AS
    WHERE LiveCampaign_SubscriberList_Email.Email = #tmp.Email COLLATE Slovenian_CI_AS
    AND tblEmailBlackList.PortalID >= 0 OR tblEmailBlackList.PortalID =- 1)
    AS LocalBlockList

FROM LiveCampaign_SubscriberList_Email

这是我需要转换成字符串的部分：

(SELECT DISTINCT PortalLocalization.PortalName
    FROM tblEmailBlackList
    LEFT JOIN tblLiveCampaignSettings ON tblLiveCampaignSettings.ModuleID = tblEmailBlackList.ModuleID
    LEFT JOIN PortalLocalization ON PortalLocalization.PortalID = tblEmailBlackList.PortalID AND PortalLocalization.CultureCode = 'sl-SI'
    LEFT JOIN #tmp ON tblEmailBlackList.Email = #tmp.Email COLLATE Slovenian_CI_AS
    WHERE LiveCampaign_SubscriberList_Email.Email = #tmp.Email COLLATE Slovenian_CI_AS
    AND tblEmailBlackList.PortalID >= 0 OR tblEmailBlackList.PortalID =- 1)

Result 将是一个字符串，然后将其插入到表中的同一行中，因为该子查询的结果应该是

【问题讨论】：

那么你需要给我们一个逻辑，通过它我们可以限制这个查询只返回一行。

@TimBiegeleisen 你这是什么意思？

所以你想聚合从你给出的查询返回的所有PortalName，用一些东西分隔（比如说，如果它返回两行 - 'A'和'B'，你希望它是' A, B'?) 然后插入到哪里？

@MarcinJ 是的，可以返回多个 PortalName，我希望所有的都在一行中，并且插入的位置与子查询的结果相同。我将在其中添加更多代码

哪个 SQL Server 版本？能否请您添加 sql-server- 标签？

【参考方案1】：

因此，您需要将返回的行聚合为一个。由于您使用的是 SQL Server 2014，因此 STRING_AGG 不可用，因此我们将使用 XML aggregation trick。试试这个：

SELECT DISTINCT LiveCampaign_SubscriberList_Email.Email, Firstname, Lastname, dbo.spValueToString(Subscribed) AS Subscribed,

dbo.spValueToString((SELECT COUNT(*) 
    FROM tblEmailBlackList
    WHERE tblEmailBlackList.Email = LiveCampaign_SubscriberList_Email.Email and tblEmailBlackList.PortalID = -2)) As GeneralBlockList,
STUFF((
    SELECT DISTINCT ',' + PortalLocalization.PortalName
    FROM tblEmailBlackList
    LEFT JOIN tblLiveCampaignSettings ON tblLiveCampaignSettings.ModuleID = tblEmailBlackList.ModuleID
    LEFT JOIN PortalLocalization ON PortalLocalization.PortalID = tblEmailBlackList.PortalID AND PortalLocalization.CultureCode = 'sl-SI'
    LEFT JOIN #tmp ON tblEmailBlackList.Email = #tmp.Email COLLATE Slovenian_CI_AS
    WHERE LiveCampaign_SubscriberList_Email.Email = #tmp.Email COLLATE Slovenian_CI_AS
    AND tblEmailBlackList.PortalID >= 0 OR tblEmailBlackList.PortalID =- 1
FOR XML PATH(''), TYPE).value('.', 'NVARCHAR(MAX)'), 1, 1, '')
    AS LocalBlockList

FROM LiveCampaign_SubscriberList_Email

【讨论】：

解决了，谢谢！还刚刚注意到我将不得不使用 UNION，我认为这不适用于 FOR XML，但我会尝试解决它