mysql - 是否可以在 MySQL 中将 DECIMAL 转换为 DOUBLE？

Question

我知道所有数值含义，即浮点格式固有的可能舍入问题，但就我而言，我在 MySQL 中有我想要的 DECIMAL 列直接在 MySQL 查询中而不是下游转换为 DOUBLE。

有人能帮忙吗？

Answer 1

SELECT my_decimal_field + 0E0 FROM my_table

MySQL 手册中的以下引述解释了它是如何工作的:

9.1.2 Numeric Literals

Number literals include exact-value (integer and DECIMAL) literals and approximate-value (floating-point) literals.

Numbers represented in scientific notation with a mantissa and exponent are approximate-value numbers.

12.22.3 Expression Handling

Handling of a numeric expression depends on what kind of values the expression contains:

• If any approximate values are present, the expression is approximate and is evaluated using floating-point arithmetic.