逻辑运算符

一元逻辑运算符

  • 支持运算符:!
  • 输入数据类型:BOOLEAN
  • 输出数据类型:BOOLEAN
  • 注意:!的优先级很高,记得使用括号调整优先级。

二元逻辑运算符

  • 支持运算符

    • AND:and,&, &&
    • OR:or,|,||
  • 输入数据类型:BOOLEAN

  • 返回类型 BOOLEAN

  • 注意:当某个时间戳下左操作数和右操作数都为BOOLEAN类型时,二元逻辑操作才会有输出结果。

示例:

  1. select a, b, a > 10, a <= b, !(a <= b), a > 10 && a > b from root.test;

运行结果

  1. IoTDB> select a, b, a > 10, a <= b, !(a <= b), a > 10 && a > b from root.test;
  2. +-----------------------------+-----------+-----------+----------------+--------------------------+---------------------------+------------------------------------------------+
  3. | Time|root.test.a|root.test.b|root.test.a > 10|root.test.a <= root.test.b|!root.test.a <= root.test.b|(root.test.a > 10) & (root.test.a > root.test.b)|
  4. +-----------------------------+-----------+-----------+----------------+--------------------------+---------------------------+------------------------------------------------+
  5. |1970-01-01T08:00:00.001+08:00| 23| 10.0| true| false| true| true|
  6. |1970-01-01T08:00:00.002+08:00| 33| 21.0| true| false| true| true|
  7. |1970-01-01T08:00:00.004+08:00| 13| 15.0| true| true| false| false|
  8. |1970-01-01T08:00:00.005+08:00| 26| 0.0| true| false| true| true|
  9. |1970-01-01T08:00:00.008+08:00| 1| 22.0| false| true| false| false|
  10. |1970-01-01T08:00:00.010+08:00| 23| 12.0| true| false| true| true|
  11. +-----------------------------+-----------+-----------+----------------+--------------------------+---------------------------+------------------------------------------------+