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Important SQL server functions - numeric functions

2022-07-28 04:24:00 【Navicat China】

The first 2 part ： Number function

Like most modern relational database products ,SQL Server Loaded the set of built-in functions . Although some functions are very similar on the whole , But the exact name and signature may be different . therefore , We'd better review the common SQL Functional SQL Server Specific implementation . In this series of The first 1 part in , We discussed string functions . In today's article , We will continue to discuss numerical functions , This is very useful for generating statistics and calculating values ！

ABS

This is not the abdominal muscles that people train for going to the beach . contrary ,ABS yes “Absolute（ absolute ）” Abbreviation . therefore ,ABS Function takes a numeric value as its argument , And return its absolute equivalent . In simpler terms ,ABS Returns the given number （ Whether it's positive or negative ） Positive form of . This is the function signature ：

ABS(inputNumber)

In mathematics and statistics , deviation （deviation） It measures the value of a variable and some other value （ It is usually the mean or average value of the variable ） A measure of the difference . Deviations can be signed or unsigned . The latter is ABS Function will help you solve . Here's a right ClassicModels Query of sample database , The database shows the signed and unsigned credit lines of customers grouped by city （ absolute ） deviation ：

ROUND

Another very common numerical function is ROUND. The implementation of rounding functions can be very different . Some are only rounded to integers , Others allow you to specify the number of decimal places to round . and SQL Server Of ROUND Function can accept up to three parameters ：

ROUND(number, decimals, operation)

number： Floating point number to round （ Decimal system ）
decimals： Round the number to the number of decimal places
operation： Optional parameters that affect the rounding operation . If the value is 0（ Or omit ）, Then the function performs regular rounding , thus 5 Or a larger number will increase to the next digit . except 0 Any value other than will cause the function to truncate the result to decimal places .

It is very common to round the value of money to two decimal places . This is our previous query with rounded numbers ：

CEILING

CEILING The function is similar to ROUND, Except that it is always rounded up to the next integer value . therefore ,25.01 and 25.75 Will be rounded up to 26. This is its grammar ：

CEILING(number)

Let's go CEILING Function is applied to our previous query , Round the credit limit to the nearest integer and pass CEILING Compare the filtered credit limit ：

FLOOR

FLOOR yes CEILING Opposite side of function ; It always rounds a number to the first integer less than or equal to that number . For positive numbers ,FLOOR Will simply truncate the decimal without changing the next highest integer . however , For negative numbers , It does increment integers down . for example ,-0.5 Of FLOOR yes -1, Because it is less than -0.5 The first integer of .

FLOOR(number)

Without using ABS In the case of FLOOR Function applied to sample queries , Shows its effect on positive and negative numbers ：

summary

In today's article , We introduced SQL Server Some of the most important numerical functions of . thereinafter , We will study the date function . If you are right about Navicat for SQL Server Interested in , Free trial 14 God ！