9.1.2 Numeric Literals
Number literals include exact-value (integer and
DECIMAL) literals and approximate-value (floating-point) literals.
Integers are represented as a sequence of digits. Numbers may include
. as a decimal separator. Numbers may be preceded by
+ to indicate a negative or positive value, respectively. Numbers represented in scientific notation with a mantissa and exponent are approximate-value numbers.
Exact-value numeric literals have an integer part or fractional part, or both. They may be signed. Examples:
Approximate-value numeric literals are represented in scientific notation with a mantissa and exponent. Either or both parts may be signed. Examples:
Two numbers that look similar may be treated differently. For example,
2.34 is an exact-value (fixed-point) number, whereas
2.34E0 is an approximate-value (floating-point) number.
DECIMAL data type is a fixed-point type and calculations are exact. In MySQL, the
DECIMAL type has several synonyms:
FIXED. The integer types also are exact-value types. For more information about exact-value calculations, see Section 12.22, “Precision Math”.
An integer may be used in floating-point context; it is interpreted as the equivalent floating-point number.