多列 INTO 多变量

我正在将 SQL 从 Teradata 转换为 SQLServer

在 Teradata 中，他们有格式

SELECT col1, col2
FROM table1
INTO @variable1, @variable2

在 SQLServer 中，我发现

SET @variable1 = (
SELECT col1
FROM table1
);

每个语句只允许一列/变量。如何使用一个 SELECT 语句分配2个或更多变量？

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最佳答案 
SELECT @variable1 = col1, @variable2 = col2
FROM table1
小开 
SELECT @var = col1,
@var2 = col2
FROM   Table

Here is some interesting information about SET / SELECT

  • SET is the ANSI standard for variable assignment, SELECT is not.
  • SET can only assign one variable at a time, SELECT can make multiple assignments at once.
  • If assigning from a query, SET can only assign a scalar value. If the query returns multiple values/rows then SET will raise an error. SELECT will assign one of the values to the variable and hide the fact that multiple values were returned (so you'd likely never know why something was going wrong elsewhere - have fun troubleshooting that one)
  • When assigning from a query if there is no value returned then SET will assign NULL, where SELECT will not make the assignment at all (so the variable will not be changed from it's previous value)
  • As far as speed differences - there are no direct differences between SET and SELECT. However SELECT's ability to make multiple assignments in one shot does give it a slight speed advantage over SET.

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