使用基于Count的IF ELSE语句执行不同的Insert语句 [英] Using IF ELSE statement based on Count to execute different Insert statements

问题描述

当我在我的数据库中搜索时，如果我发现某个特定项目不存在，我会运行一个 INSERT 语句，如果我找到一个或多个这个项目，我会运行一个不同的 INSERT 语句.

While I am searching through my database, I run an INSERT statement if I find that a particular item does not exist, and I run a different INSERT statement if I find one or more of this item.

我不完全确定如何使用 IF ELSE 表达式.

I am not entirely sure how to use the IF ELSE expressions.

我目前得到的是一个语句，它会统计目标数据出现的次数；如果大于 0 则打印 TRUE，否则打印 FALSE.我找不到任何示例来帮助我理解如何使用它来运行两个不同的 INSERT 语句.

What I have so far is a statement that will count the number of times the target data appears; it will print TRUE if it is greater than 0, if not, it will print FALSE. I can't find any examples to help me understand how I can use this to run two different INSERT statements.

这是我目前所拥有的:

SELECT CASE WHEN COUNT(*)>0 THEN 'TRUE' ELSE 'FALSE' END
(
  SELECT [Some Column], COUNT(*) TotalCount
  FROM INCIDENTS
  WHERE [Some Column] = 'Target Data'
  GROUP BY [Some Column]
)

推荐答案

根据您的需要，这里有几种方法:

Depending on your needs, here are a couple of ways:

IF EXISTS (SELECT * FROM TABLE WHERE COLUMN = 'SOME VALUE')
    --INSERT SOMETHING
ELSE
    --INSERT SOMETHING ELSE

或者更长一点

DECLARE @retVal int

SELECT @retVal = COUNT(*) 
FROM TABLE
WHERE COLUMN = 'Some Value'

IF (@retVal > 0)
BEGIN
    --INSERT SOMETHING
END
ELSE
BEGIN
    --INSERT SOMETHING ELSE
END 

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