在触发器中使用光标更改 db_sendmail 的主题

Question

SQl Server 2008 R2 - 我有一个触发器，设置为将电子邮件发送到由第三方系统监控的特定电子邮件地址，该系统根据该消息的主题。对此的限制是每条消息的主题中只能有一个组号。但是我需要从触发器向至少两个组发送相同的消息，这意味着必须生成两封具有两个不同主题行的单独电子邮件。我在想触发器中的光标可能会完成此操作，但我不确定如何编写它。因此，在下面的代码中，我有 @cat，每次触发器启动时，我都需要发送一封主题为 'ED' 的电子邮件。然后我需要发送另一封电子邮件，主题是根据当前用于设置主题行的案例陈述的条件设置的。我已经按如下方式更新了代码，并且通过删除标量变量已移至基于集合的触发器（？？）我还创建了信息并将其插入到 "email" table 中服务设置为每 10 秒运行，并通过电子邮件发送所有设置为 0 的记录，然后将标志更新为 1。

新代码 -

CREATE TABLE [dbo].[tb_BatchEmail] (
    [BatchEmailID] [bit] NOT NULL DEFAULT 0
    ,[To] [varchar](50) NOT NULL DEFAULT 'someemail' --will never change
    ,[Body] [varchar](255) NULL
    ,[Subject] [varchar](20) NOT NULL
    ,[Profile] [varchar](50) NOT NULL DEFAULT 'Alert' --will never change
    ,[OrderID] [varchar] (25) NULL
    ,[OrderDateTime] [datetime] NULL
    ,[SentDateTime] [datetime] NULL
    ,CONSTRAINT msg_pk PRIMARY KEY CLUSTERED (BatchEmailID)
    ) ON [PRIMARY]
GO



  ALTER TRIGGER [dbo].[VeOrders] ON [dbo].[Orders]
        FOR INSERT
        AS
            SELECT @visitid = i.VisitID
    ,@priority = Priority
    ,@cat = Category
    ,@procedure = OrderedProcedureName
    ,@orderid = OrderID
    ,@orderdate = OrderDateTime
    ,@locationid = CurrentLocationID
    ,@roomid = CASE 
        WHEN RoomTreatmentID IS NULL
            THEN 'No Room#'
        ELSE RoomTreatmentID
        END
FROM inserted i
INNER JOIN livedb.dbo.EdmPatients edp
    ON edp.VisitID = i.VisitID
WHERE Priority = 'STAT'
    AND Category IN ('CT', 'MRI', 'XRAY', 'US', 'NUC', 'ECHO')
    AND CurrentLocationID = 'ED'

IF @cat IN ('CT', 'MRI', 'XRAY', 'US', 'NUC', 'ECHO')
    AND @priority = 'STAT'
    AND @locationid = 'ED'
BEGIN
    DECLARE @msg VARCHAR(500)
    DECLARE @subject VARCHAR(500)

    SET @msg = @roomid + '-' + @procedure + '-' + @priority + '.' --+ 'Order DateTime/Number ' + @order + '/+ @locationid + ' '  + @orderid
    SET @subject = CASE 
            WHEN @cat = 'US'
                THEN 'Test Ultra Sound'
            WHEN @cat = 'CT'
                THEN 'Test C T'
            WHEN @cat = 'XRAY'
                THEN 'Test X-Ray'
            END

    INSERT INTO livedb.dbo.tb_BatchEmail (
        Body
        ,[Subject]
        ,OrderID
        ,OrderDateTime
        )
    SELECT Body = @msg
        ,[Subject] = @subject
        ,OrderID = @orderid
        ,OrderDateTime = @orderdate

END

旧代码 -

ALTER TRIGGER [dbo].[VeOrders] ON [dbo].[Orders]
FOR INSERT
AS
IF NOT EXISTS (
        SELECT *
        FROM dbo.EdmPatients
        WHERE CurrentLocationID = 'ED'
        )
    RETURN

DECLARE @priority VARCHAR(50)
DECLARE @cat VARCHAR(50)
DECLARE @procedure VARCHAR(50)
DECLARE @orderid VARCHAR(50)
DECLARE @locationid VARCHAR(10)
DECLARE @roomid VARCHAR(10)
DECLARE @visitid VARCHAR(50)

SELECT @visitid = VisitID
    ,@priority = Priority
    ,@cat = Category
    ,@procedure = OrderedProcedureName
    ,@orderid = OrderID
    ,@locationid = CurrentLocationID
    ,@roomid = CASE 
        WHEN RoomTreatmentID IS NULL
            THEN 'No Room#'
        ELSE RoomTreatmentID
        END
FROM inserted i
INNER JOIN dbo.EdmPatients edp
    ON edp.VisitID = i.VisitID
WHERE Priority = 'STAT'
    AND Category IN ('CT', 'MRI', 'XRAY', 'US', 'NUC', 'ECHO')
    AND CurrentLocationID = 'ED'

IF @cat IN ('CT', 'MRI', 'XRAY', 'US', 'NUC', 'ECHO')
    AND @priority = 'STAT'
    AND @locationid = 'ED'
BEGIN
    DECLARE @msg VARCHAR(500)
    DECLARE @subject VARCHAR(500)

    SET @msg = @roomid + '-' + @procedure + '-' + @priority + '.' 
    SET @subject = CASE
            WHEN @cat = 'CT'
                THEN '55194'
            WHEN @cat = 'US'
                THEN '59843'
            WHEN @cat = 'XRAY'
                THEN '70071'
            END

    EXEC msdb.dbo.sp_send_dbmail 
         @recipients = N'someemail'
        ,@body = @msg
        ,@subject = @subject
        ,@profile_name = 'Alerts'
END

Answer 1

我会把创建和发送电子邮件的顾虑分开。有一项服务，其唯一的工作就是发送电子邮件。电子邮件是抽象的，因为它们都有发件人、收件人、正文和主题。创建一个包含所有这些字段的 table（例如名为 BatchEmail）。

那你的触发器就简单了。它只是在正常的 select 语句中插入您的 BatchEmail table。

insert into BatchEmail
(To, Body, Subject, Profile)
select N'someemail',
       @msg,
       CASE
            WHEN @cat = 'CT'
                THEN '55194'
            WHEN @cat = 'US'
                THEN '59843'
            WHEN @cat = 'XRAY'
                THEN '70071'
            END,
        'Alerts'

您的 BatchEmail table 应该有一些列或标志指示何时或是否发送。

您的服务（甚至 table 上的插入触发器，如果您真的喜欢触发器）可能一次只 select 1 行尚未处理。

while true
begin

    select top 1 
           @BatchEmailID = batchEmailID,
           @To = to,
           @From = from,
           @Body = body,
           @Subject = subject,
           @ProfileName = ProfileName
    from BatchEmail
    where processed = 0

    if(@BatchEmailID is null)
    break;

    exec msdb.dbo.sp_send_dbmail @To, @Body, @Subject, @ProfileName

    update BatchEmail
    set processed = 1
    where BatchEmailID = @BatchEmailID

end

如果您仍然不想拥有单独的服务并坚持在触发器中执行所有这些操作，您可以将 @BatchEmail 变成一个 table 变量，仍然带有一个 @Processed 位列和 select 一次一行，在每行之后更新@Processed。

在触发器中使用光标更改 db_sendmail 的主题

Using a cursor in a trigger to change subject of db_sendmail

sql-server

triggers

sp-send-dbmail

cursor