Oracle PL/SQL provides several numeric data types to store numbers of various sizes and precision, including the FLOAT data type. The FLOAT data type is used to store floating-point numbers, which are numbers with a decimal point that can have a variable number of digits both before and after the decimal point.
In PL/SQL, there are two subtypes of FLOAT data type: BINARY_FLOAT and BINARY_DOUBLE. BINARY_FLOAT can store single-precision floating-point numbers, while BINARY_DOUBLE can store double-precision floating-point numbers.
BINARY_FLOAT is a 32-bit floating-point number that can represent a range of values from approximately 1.4E-45 to 3.4E+38 with a precision of up to 24 significant digits. BINARY_DOUBLE is a 64-bit floating-point number that can represent a range of values from approximately 4.9E-324 to 1.8E+308 with a precision of up to 53 significant digits.
Both BINARY_FLOAT and BINARY_DOUBLE have a binary representation that can lead to some precision issues when performing arithmetic operations with them. Therefore, it is essential to be careful when using them and to consider using other data types, such as DECIMAL or NUMBER, for more precise calculations.
To declare a FLOAT variable in PL/SQL, you can use the following syntax:
DECLARE my_float BINARY_FLOAT; my_double BINARY_DOUBLE; BEGIN -- Code goes here END;
You can also assign values to FLOAT variables using literals or expressions:
DECLARE my_float BINARY_FLOAT := 1.234; my_double BINARY_DOUBLE := my_float * 1000; BEGIN DBMS_OUTPUT.PUT_LINE(my_float); DBMS_OUTPUT.PUT_LINE(my_double); END;
In conclusion, the FLOAT data type in Oracle PL/SQL is used to store floating-point numbers, and it comes in two subtypes: BINARY_FLOAT and BINARY_DOUBLE. It is essential to be aware of the precision issues that may arise when using floating-point numbers and to consider other data types for more precise calculations.