MySQL 8.0 Reference Manual Including MySQL NDB Cluster 8.0

11.1.1 Numeric Type Overview

A summary of the numeric data types follows. For additional information about properties and storage requirements of the numeric types, see Section 11.2, “Numeric Types”, and Section 11.8, “Data Type Storage Requirements”.

For integer types, M indicates the maximum display width. The maximum display width is 255. Display width is unrelated to the range of values a type can contain, as described in Section 11.2, “Numeric Types”.

For floating-point and fixed-point types, M is the total number of digits that can be stored.

As of MySQL 8.0.17, the display width attribute is deprecated for integer data types and support for it will be removed in a future MySQL version.

If you specify ZEROFILL for a numeric column, MySQL automatically adds the UNSIGNED attribute to the column.

As of MySQL 8.0.17, the ZEROFILL attribute is deprecated for numeric data types and support for it will be removed in a future MySQL version. Consider using an alternative means of producing the effect of this attribute. For example, applications could use the LPAD() function to zero-pad numbers up to the desired width, or they could store the formatted numbers in CHAR columns.

Numeric data types that permit the UNSIGNED attribute also permit SIGNED. However, these data types are signed by default, so the SIGNED attribute has no effect.

As of MySQL 8.0.17, the UNSIGNED attribute is deprecated for columns of type FLOAT, DOUBLE, and DECIMAL (and any synonyms) and support for it will be removed in a future MySQL version. Consider using a simple CHECK constraint instead for such columns.

SERIAL is an alias for BIGINT UNSIGNED NOT NULL AUTO_INCREMENT UNIQUE.

SERIAL DEFAULT VALUE in the definition of an integer column is an alias for NOT NULL AUTO_INCREMENT UNIQUE.

Warning

When you use subtraction between integer values where one is of type UNSIGNED, the result is unsigned unless the NO_UNSIGNED_SUBTRACTION SQL mode is enabled. See Section 12.10, “Cast Functions and Operators”.