在 T-SQL 查询的 SELECT 子句中使用比较运算符
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Using comparison operators in SELECT clause of T-SQL query
提问by abatishchev
How to select a result of comparison operator as a field with type BIT?
如何选择比较运算符的结果作为 BIT 类型的字段？
How it does work in C#:
它是如何工作的C#：
bool isGreater = FieldA > FieldB;
How it doesn't work in T-SQL:
它如何不起作用T-SQL：
SELECT (FieldA > FieldB) AS BIT FROM t
How to write such task properly?
如何正确编写这样的任务？
回答by Rockcoder
You should use CASE clause:
您应该使用 CASE 子句：
CASE
WHEN FieldA > FieldB THEN 1
ELSE 0
END AS [BIT]
回答by George Mastros
Select Convert(Bit, Case When FieldA > FieldB Then 1 Else 0 End) As YourBitColumn
If you want to return a BIT, then you need the convert (or cast) to a bit data type, otherwise, SQL would interpret the hard coded constant (1 or 0) as an integer.
如果要返回 BIT，则需要将转换（或强制转换）为位数据类型，否则 SQL 会将硬编码常量（1 或 0）解释为整数。
