sql - SQL 中的管道运算符有什么作用？

Question

我正在重新开发一个应用程序，发现了这个sql语句，|是什么意思？角色在这部分做(au.ExNetBits | 8) ，我以前没见过，网上也找不到答案？

SELECT au.AccountID,au.ExNetBits FROM AccountUser au (NOLOCK)<br/> WHERE au.CDAGUserId=102 and <strong>(au.ExNetBits | 8)</strong> = au.ExNetBits

Answer 1

来自the MSDN documentation ,

| (Bitwise OR) (Transact-SQL)

Performs a bitwise logical OR operation between two specified integer values as translated to binary expressions within Transact-SQL statements.

...

The bitwise | operator performs a bitwise logical OR between the two expressions, taking each corresponding bit for both expressions. The bits in the result are set to 1 if either or both bits (for the current bit being resolved) in the input expressions have a value of 1; if neither bit in the input expressions is 1, the bit in the result is set to 0.

If the left and right expressions have different integer data types (for example, the left expression is smallint and the right expression is int), the argument of the smaller data type is converted to the larger data type. In this example, the smallint expression is converted to an int.

例如，参见this fiddle ,

SELECT 1 | 1, 1 | 2, 2 | 4, 3 | 5;

输出

1    3    6    7

要解释此行为，您必须考虑操作数的位模式，

1 | 1

  00000001  = 1
| 00000001  = 1
_______________
  00000001  = 1

1 | 2

  00000001  = 1
| 00000010  = 2
_______________
  00000011  = 3

2 | 4

  00000010  = 2
| 00000100  = 4
_______________
  00000110  = 6

3 | 5

  00000011  = 3
| 00000101  = 5
_______________
  00000111  = 7