oracle四舍五入保留两位小数的函数

Introduction

In Oracle, there are several ways to round a number to two decimal places. This can be useful when dealing with financial calculations or when you need to display data in a specific format. In this article, we will explore different functions that can be used to achieve this rounding in Oracle.

ROUND Function

The ROUND function in Oracle is commonly used to round numbers to a specified number of decimal places. The syntax for the ROUND function is as follows:

ROUND(number, precision)

where number is the value to be rounded and precision is the number of decimal places to round to. For example, if we want to round the number 3.14159 to two decimal places, we can use the following query:

SELECT ROUND(3.14159, 2) FROM dual;

This will return the result 3.14.

TRUNC Function

The TRUNC function in Oracle can also be used to truncate a number to a specified number of decimal places. The syntax for the TRUNC function is similar to the ROUND function:

TRUNC(number, precision)

where number is the value to be truncated and precision is the number of decimal places to keep. For example, if we want to truncate the number 3.14159 to two decimal places, we can use the following query:

SELECT TRUNC(3.14159, 2) FROM dual;

This will return the result 3.14.

CEIL and FLOOR Functions

In addition to rounding and truncating, Oracle also provides the CEIL and FLOOR functions. These functions round a number up or down to the nearest integer or specified decimal place.

The CEIL function rounds a number up to the nearest integer or decimal place. For example, if we want to round the number 3.14159 up to two decimal places, we can use the following query:

SELECT CEIL(3.14159 * 100) / 100 FROM dual;

This will return the result 3.15.

The FLOOR function, on the other hand, rounds a number down to the nearest integer or decimal place. Using the same example, if we want to round the number 3.14159 down to two decimal places, we can use the following query:

SELECT FLOOR(3.14159 * 100) / 100 FROM dual;

This will return the result 3.14.

Conclusion

In Oracle, there are multiple functions available to round a number to a specified number of decimal places. The ROUND function is the most commonly used, but the TRUNC, CEIL, and FLOOR functions can also be used depending on the desired rounding behavior. By understanding these functions, you can handle rounding requirements effectively in your Oracle database applications.

Remember to always refer to the Oracle documentation for further details and examples on how to use these functions.