📅 最后修改于: 2020-11-29 05:53:44 🧑 作者: Mango
MongoDB运算符以及更高级的运算符用于测试是否相等和不相等。
比较运算符都在WHERE子句中使用，以确定选择哪个记录。这里是比较运算符，你可以在MariaDB的使用的列表：
句法：
| Index | Comparison Operator | Description |
|---|---|---|
| 1. | = | equal |
| 2. | <=> | equal (safe to compare null values) |
| 3. | <> | not equal |
| 4. | != | not equal |
| 5. | > | greater than |
| 6. | >= | greater than or equal |
| 7. | < | less than |
| 8. | <= | less than or equal |
| 9. | in ( ) | matches a value in a list |
| 10. | not | negates a condition |
| 11. | between | within a range (inclusive) |
| 12. | is null | null value |
| 13. | is not null | non-null value |
| 14. | like | pattern matching with % and _ |
| 15. | exists | condition is met if subquery returns at least one row |