What to fill in the double type in mysql

The double type in mysql can store a wide range of values, including positive numbers, negative numbers, decimals, etc., for example: 1. Integers, such as 100, -50, 0; 2. Decimals, such as 3.14, -2.5 ;3. Scientific notation, such as 1.23e-4, 5.67E8.

Operating system for this tutorial: Windows 10 system, MySQL 8 version, Dell G3 computer.

In MySQL, DOUBLE is a floating-point data type used to store double-precision floating-point numbers (64-bit floating-point numbers). The DOUBLE type can store a wide range of values, including positive numbers, negative numbers, decimals, etc.

When you want to fill in a DOUBLE type field, you can fill in legal values, for example:

• Integers: 100, -50, 0

• Decimal: 3.14, -2.5

• Scientific notation: 1.23e-4, 5.67E8 (representing -4 of 1.23 times 10 The sum of 5.67 multiplied by 10 to the 8th power)

The following are some examples:

CREATE TABLE my_table (
  id INT,
  value DOUBLE
);
INSERT INTO my_table (id, value) VALUES (1, 3.14);
INSERT INTO my_table (id, value) VALUES (2, -6.25);

It should be noted that due to floating point precision issues, for some specific The numerical value may contain rounding errors. If high-precision numerical calculations are required, it is recommended to use the DECIMAL type instead of the DOUBLE type.

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