In MySQL, the NUMERIC data type is used to store numeric values with precision and scale. It is often used for representing fixed-point numbers where precision is critical. The NUMERIC data type is synonymous with DECIMAL in MySQL, and both can be used interchangeably.
Here’s a breakdown of the key characteristics of the NUMERIC data type:
Syntax
The syntax for declaring a NUMERIC data type in MySQL is as follows:
NUMERIC(precision, scale)
precision: The total number of digits in the number.
scale: The number of digits to the right of the decimal point.
For example:
CREATE TABLE example_table ( column_name NUMERIC(10, 2) );
This creates a column named column_name with a total of 10 digits, 2 of which can be used for decimal places.
Precision and Scale
Precision refers to the total number of digits in a number, both to the left and right of the decimal point.
Scale refers to the number of digits to the right of the decimal point.
For instance, in NUMERIC(10, 2), there are a total of 10 digits, and 2 digits are reserved for the decimal places.
Storage
NUMERIC values are stored as strings and can require more storage space compared to other numeric types like INT or FLOAT. The storage size depends on the precision and scale specified.
Use Cases
NUMERIC is suitable for scenarios where precision is crucial, such as when dealing with financial data or measurements where exact values are required. It ensures that the stored values retain the specified precision without any rounding errors.
Arithmetic Operations
Arithmetic operations involving NUMERIC values follow the specified precision and scale. The result of an operation will have the same precision and scale as the operands.
SELECT NUMERIC_COLUMN1 + NUMERIC_COLUMN2 FROM example_table;
Comparison and Sorting
NUMERIC values can be compared using standard comparison operators (<, <=, >, >=, =), and sorting is based on the numeric value.
SELECT * FROM example_table ORDER BY NUMERIC_COLUMN;
In summary, the NUMERIC data type in MySQL is designed for scenarios where precise numeric representation is essential. It allows the definition of both precision and scale, ensuring accurate storage and retrieval of numeric values in the database.