sql null if example - Brave Search

MySQL IF NOT NULL, then display 1, else display 0

stackoverflow.com › questions › 9387839 › mysql-if-not-null-then-display-1-else-display-0

Instead of COALESCE(a.addressid,0) AS addressexists, use CASE:

CASE WHEN a.addressid IS NOT NULL 
       THEN 1
       ELSE 0
END AS addressexists

or the simpler:

(a.addressid IS NOT NULL) AS addressexists

This works because TRUE is displayed as 1 in MySQL and FALSE as 0.

Answer from ypercubeᵀᴹ on Stack Overflow

w3schools.com › sql › sql_null_values.asp

SQL NULL Values - IS NULL and IS NOT NULL

The following SQL lists all customers with a value in the "Address" field: SELECT CustomerName, ContactName, Address FROM Customers WHERE Address IS NOT NULL; Try it Yourself » ... If you want to use W3Schools services as an educational institution, team or enterprise, send us an e-mail: [email protected]

w3schools.com › sql › sql_isnull.asp

SQL IFNULL(), ISNULL(), COALESCE(), and NVL() Functions

SQL Examples SQL Editor SQL Quiz ... and may contain NULL values. ... In the example above, if any of the "UnitsOnOrder" values are NULL, the result will be NULL....

Videos

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October 28, 2021

SQL SERVER||NULLIF Function in SQL and use case of NULLIF - YouTube

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Using SQL NULLIF with Missing Values | Essential SQL - YouTube

Microsoft Learn

learn.microsoft.com › en-us › sql › t-sql › queries › is-null-transact-sql

IS NULL (Transact-SQL) - SQL Server | Microsoft Learn

The following example returns the full names of all employees with middle initials. SELECT FirstName, LastName, MiddleName FROM DIMEmployee WHERE MiddleName IS NOT NULL ORDER BY LastName DESC;

w3schools.com › sql › func_mysql_ifnull.asp

MySQL IFNULL() Function

SQL Examples SQL Editor SQL Quiz SQL Exercises SQL Server SQL Syllabus SQL Study Plan SQL Bootcamp SQL Certificate SQL Training ... The IFNULL() function returns a specified value if the expression is NULL.

w3schools.com › sql › func_sqlserver_nullif.asp

SQL Server NULLIF() Function

SQL Examples SQL Editor SQL Quiz SQL Exercises SQL Server SQL Syllabus SQL Study Plan SQL Bootcamp SQL Certificate SQL Training ... The NULLIF() function returns NULL if two expressions are equal, otherwise it returns the first expression.

mimo.org › glossary › sql › is-not-null

SQL IS NOT NULL Condition: Syntax, Usage, and Examples

You should also use this condition when comparing values that could be empty, as comparison operators like `=` and `!=` don't behave correctly with `NULL`. ## When to Use SQL IS NOT NULL ### Filter Out Incomplete Records Use this condition to ignore rows with missing data. For example, if you're ...

techonthenet.com › sql_server › functions › nullif.php

SQL Server: NULLIF Function

SELECT NULLIF('TechOnTheNet.com', 'TechOnTheNet.com'); Result: NULL (returns NULL because values are the same) SELECT NULLIF('CheckYourMath.com', 'TechOnTheNet.com'); Result: 'CheckYourMath.com' (returns first value because values are different) SELECT NULLIF(12, 12); Result: NULL (returns ...

stackoverflow.com › questions › 9387839 › mysql-if-not-null-then-display-1-else-display-0

if statement - MySQL IF NOT NULL, then display 1, else display 0 - Stack Overflow

Instead of COALESCE(a.addressid,0) AS addressexists, use CASE:

CASE WHEN a.addressid IS NOT NULL 
       THEN 1
       ELSE 0
END AS addressexists

or the simpler:

(a.addressid IS NOT NULL) AS addressexists

This works because TRUE is displayed as 1 in MySQL and FALSE as 0.

SELECT c.name, IF(a.addressid IS NULL,0,1) AS addressexists
FROM customers c
LEFT JOIN addresses a ON c.customerid = a.customerid
WHERE customerid = 123

Find elsewhere

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stratascratch.com › blog › introduction-to-ifnull-function-in-sql

Introduction to IFNULL() Function in SQL - StrataScratch

If NULL, the second expression is evaluated, and so on, until a NON-NULL value is found. In this example, we apply the SQL IFNULL() function to a hard-level interview question asked by Google.

datacamp.com › doc › mysql › mysql-ifnull

MySQL IFNULL Keyword: Usage & Examples

sql SELECT product_name, price, quantity, IFNULL(price * quantity, 0) AS total_value FROM products; This example uses `IFNULL` to ensure that any NULL `price` or `quantity` results in a `total_value` of `0`, preventing calculation errors.

stackoverflow.com › questions › 14962970 › sql-query-if-value-is-null-then-return-1

t sql - SQL query, if value is null then return 1 - Stack Overflow

You can use a CASE statement.

SELECT 
    CASE WHEN currate.currentrate IS NULL THEN 1 ELSE currate.currentrate END
FROM ...

You can use COALESCE:

SELECT  orderhed.ordernum, 
    orderhed.orderdate, 
    currrate.currencycode,  
    coalesce(currrate.currentrate, 1) as currentrate
FROM orderhed 
LEFT OUTER JOIN currrate 
    ON orderhed.company = currrate.company 
    AND orderhed.orderdate = currrate.effectivedate

Or even IsNull():

SELECT  orderhed.ordernum, 
    orderhed.orderdate, 
    currrate.currencycode,  
    IsNull(currrate.currentrate, 1) as currentrate
FROM orderhed 
LEFT OUTER JOIN currrate 
    ON orderhed.company = currrate.company 
    AND orderhed.orderdate = currrate.effectivedate

Here is an article to help decide between COALESCE and IsNull:

http://www.mssqltips.com/sqlservertip/2689/deciding-between-coalesce-and-isnull-in-sql-server/

Microsoft Learn

learn.microsoft.com › en-us › sql › t-sql › language-elements › nullif-transact-sql

NULLIF (Transact-SQL) - SQL Server | Microsoft Learn

USE AdventureWorks2022; GO SELECT ProductID, MakeFlag, FinishedGoodsFlag, NULLIF(MakeFlag,FinishedGoodsFlag) AS [Null if Equal] FROM Production.Product WHERE ProductID < 10; GO SELECT ProductID, MakeFlag, FinishedGoodsFlag, [Null if Equal] = CASE WHEN MakeFlag = FinishedGoodsFlag THEN NULL ELSE MakeFlag END FROM Production.Product WHERE ProductID < 10; GO · The following example creates a budgets table, loads data, and uses NULLIF to return a null if current_year is null or contains the same data as previous_year.

w3resource.com › mysql › control-flow-functions › if-null-function.php

MySQL IFNULL() function - w3resource

... -- In this example, the first argument is NULL, -- and the second argument is a string 'default value'. SELECT IFNULL(NULL, 'default value') AS result; -- The expected result will be 'default value' because the first argument is NULL.

data-flair.training › blogs › sql-null-functions

SQL Null Functions - ISNULL, IFNULL, Combine, & NULLIF - DataFlair

March 11, 2021 - Some of the functions are as follows: Let us now have a look at our demo database – ‘DataFlair’ Query: ... Example: Let us view the experience of each employee in DataFlair and replace the NULL value with 0 years of experience.

techonthenet.com › sql › is_null.php

SQL: IS NULL Condition

This example will update all category_id values in the products table to 100 where the category_id contains a NULL value.

programiz.com › sql › is-null-not-null

SQL IS NULL and IS NOT NULL (With Examples)

It has the following syntax: SELECT column1, column2, ... FROM table WHERE column_name IS NOT NULL; ... Here, the above SQL query retrieves all the rows from the Employee table where the value of the email column is NOT NULL. ... We can use the COUNT() function with IS NULL to count the number ...

coginiti.co › home › beginner › sql is null

What is the IS NULL Operator in SQL? - Coginiti

September 25, 2023 - If it’s zero, it means it’s sold out. Keep in mind that NULL values are treated differently than other values in SQL. When comparing two NULL values, they are considered unequal since NULL represents the absence of a value. This can sometimes lead to unexpected results, so it’s fundamental to know how your database management system handles them. For example, the following SQL statement selects all rows where column1 is NULL:

w3schools.com › mysql › mysql_null_values.asp

MySQL NULL Values - IS NULL and IS NOT NULL

The following SQL lists all customers with a value in the "Address" field: SELECT CustomerName, ContactName, Address FROM Customers WHERE Address IS NOT NULL; Try it Yourself » ... If you want to use W3Schools services as an educational institution, team or enterprise, send us an e-mail: ...

w3schools.com › mysql › mysql_ifnull.asp

MySQL IFNULL() and COALESCE() Functions

The MySQL IFNULL() function lets ... is NULL. ... If you want to use W3Schools services as an educational institution, team or enterprise, send us an e-mail: [email protected] · If you want to report an error, or if you want to make a suggestion, send us an e-mail: [email protected] · HTML Tutorial CSS Tutorial JavaScript Tutorial How To Tutorial SQL Tutorial Python ...

reddit.com › r/sql › need some knowledge on null and not null

r/SQL on Reddit: Need some knowledge on NULL and NOT NULL

December 22, 2021 -

Where and why exactly a null is used?
What is exactly null and not null? To my understanding Not null we use when its mandatory to insert some value in that field, also when we give check constraint so by default the column will be not null right?
By adding new column through alter method default values are null, so how would I be able to insert values in it and is it right to give not null constraint to that new column while adding through alter method, basically when null and when not null to be used?...

god this is so confusing please help me, ik im asking alot but im really confused

a null is used for multiple purposes -- for example, not known, not applicable, etc. theoreticians take great joy in debating which uses are valid, and whether they can be substituted by some non-null placeholder suffice to say, a null is used when you don't know what value should go there if you don't want that situation to arise, just make the column NOT NULL and you'll never be able to not insert an actual value

Thoughts in this can vary but I'll give my input. NULL should be used where it is known that there can definitely be no value. If a person's record has an optional telephone number when signing up to a website, and they do not complete a number upon their submission, then a NULL is a valid value. However, if we are utilising something like "effective from" and "effective to" of a row of data, then effective to should never be NULL, we always determine that a row is either currently effective, or is historic and superceded. As a result, the "active" row should not hold a NULL in effective to, even though it is not known. It should be a future, default date, and the column should be set with a NOT NULL constraint.