控制服务器在接受或拒绝无效数据时的严格程度的 SQL 模式。SQL modes that control how strict the server is about accepting or rejecting invalid data.

用于定点算术的 MySQL 库。The MySQL library for fixed-point arithmetic.

精确计算：对于精确数值的数字，计算不会引入浮点误差。而是使用精确精度。例如，MySQL 将数字视为.0001精确值，而非近似值，将其求和 10,000 次会得到的结果正好是1，而不是仅仅“接近”1 的值。Precise calculations: For exact-value numbers, calculations do not introduce floating-point errors. Instead, exact precision is used. For example, MySQL treats a number such as .0001 as an exact value rather than as an approximation, and summing it 10,000 times produces a result of exactly 1, not a value that is merely “close” to 1.

明确定义的舍入行为：对于精确数值，ROUND() 的结果取决于其参数，而不取决于环境因素，例如底层 C 库的工作方式。Well-defined rounding behavior: For exact-value numbers, the result of ROUND() depends on its argument, not on environmental factors such as how the underlying C library works.

平台独立性：对精确数值的操作在不同平台（如 Windows 和 Unix）上都是相同的。Platform independence: Operations on exact numeric values are the same across different platforms such as Windows and Unix.

对无效值处理的控制：溢出和除以零是可以检测到的，并且可以被视为错误。例如，你可以将对列来说过大的值视为错误，而不是将该值截断以适应列的数据类型范围。类似地，你可以将除以零视为错误，而不是作为产生 NULL 结果的操作。选择采用哪种方法取决于服务器 SQL 模式的设置。Control over handling of invalid values: Overflow and division by zero are detectable and can be treated as errors. For example, you can treat a value that is too large for a column as an error rather than having the value truncated to lie within the range of the column's data type. Similarly, you can treat division by zero as an error rather than as an operation that produces a result of NULL. The choice of which approach to take is determined by the setting of the server SQL mode.