You have to use CASE
SELECT CASE WHEN Field IS NOT NULL
THEN 'something'
ELSE 'something else'
END
W3Schools
w3schools.com › sql › sql_null_values.asp
SQL NULL Values - IS NULL and IS NOT NULL
If a field in a table is optional, ... way, the field will be saved with a NULL value. A NULL value represents an unknown, missing, or inapplicable data in a database field. It is not ......
Microsoft Learn
learn.microsoft.com › en-us › sql › t-sql › queries › is-null-transact-sql
IS NULL (Transact-SQL) - SQL Server | Microsoft Learn
... If the value of expression is NULL, IS NULL returns TRUE; otherwise, it returns FALSE. If the value of expression is NULL, IS NOT NULL returns FALSE; otherwise, it returns TRUE.
Need some knowledge on NULL and NOT NULL
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 More on reddit.com
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December 22, 2021Case When not check NULL value as defined
Here is my query using Case when, DECLARE @tbl TABLE(ID INT, Col1 DATETIME, Col2 INT) INSERT INTO @tbl VALUES (1,'2024-01-22',101),(2,'2024-01-21',102),(3,'2024-01-20',NULL) SELECT ID,Col1,Col2 ,CASE Col2 WHEN NULL THEN 'No Value' … More on learn.microsoft.com
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query - Not equal to operator is not returning NULL values in SQL Server - Database Administrators Stack Exchange
I have the following query where ... that are not equal to 1 for the column istrue. However, the results only include records with 0 and omit those with null. While I am aware that using (istrue != 1 or istrue is null) would yield the expected outcome, I am curious about the underlying mechanism causing SQL Server to exclude ... More on dba.stackexchange.com
When NULL IS NOT NULL – SQLServerCentral Forums
Microsoft SQL Server 2008 (RTM) - 10.0.1600.22 (X64) Jul 9 2008 14:17:44 Copyright (c) 1988-2008 Microsoft Corporation Developer Edition (64-bit) on Windows NT 6.1 (Build 7600: ) ... Attempting to set a non-NULL-able column's value to NULL. More on sqlservercentral.com
Videos
06:54
SQL Tutorial #17 - SQL IS NULL and IS NOT NULL | SQL NULL Values ...
02:07
SQL query to check IS Null and IS not Null data - YouTube
10:11
14 Not null constraint in sql server - YouTube
05:08
NOT NULL constraint in MS SQL Server - YouTube
03:06
SQL NOT NULL Constraint | SQL Server Tutorial for Beginners - YouTube
21:05
14. What is Not Null Constraint in SQL Server | Properties | SQL ...
Top answer 1 of 9
54
You have to use CASE
SELECT CASE WHEN Field IS NOT NULL
THEN 'something'
ELSE 'something else'
END
2 of 9
33
I know is late but just in case someone else viewing this and using MSSQL 2012 or above you could use 'IIF' statement.
I guess OP don't want to use 'IF' clausule cause is "too much code syntax" to acomplish simple stuff.
An alternative also cleaner than 'IF' statement is 'IIF'. Is just an inline 'IF' simplification.
SELECT IIF(X IS NULL, 'Is null', 'Not null') 'Column Name'
Regarding OP
SELECT IIF(a.PolicySignedDateTime IS NULL, NULL, aq.Amount) AS 'Signed Premium'
https://learn.microsoft.com/en-us/sql/t-sql/functions/logical-functions-iif-transact-sql?view=sql-server-ver15
Mimo
mimo.org › glossary › sql › is-not-null
SQL IS NOT NULL Condition: Syntax, Usage, and Examples
Some SQL tutorials call this the IS NOT NULL operator. Both names point to the same idea: testing whether a field contains an actual value instead of NULL. In SQL Server, you can use IS NOT NULL inside WHERE, CASE, JOIN, and HAVING clauses.
Hightouch
hightouch.com › sql-dictionary › sql-is-not-null
SQL IS NOT NULL - Syntax, Use Cases, and Examples | Hightouch
December 29, 2023 - SELECT columns FROM table_name WHERE column_name IS NOT NULL; columns: The columns you want to retrieve in the query. table_name: The name of the table containing the data. column_name: The name of the column you want to filter based on whether ...
TechOnTheNet
techonthenet.com › sql_server › is_not_null.php
SQL Server: IS NOT NULL Condition
INSERT INTO contacts (contact_id, last_name, first_name) SELECT employee_id, last_name, first_name FROM employees WHERE last_name IS NOT NULL; This SQL Server IS NOT NULL example will insert records into the contacts table where the last_name does not contain a null value in the employees table.
Reddit
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
Top answer 1 of 5
8
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
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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.
Programiz
programiz.com › sql › not-null
SQL NOT NULL Constraint (With Examples)
In SQL, the NOT NULL constraint in a column means that the column cannot store NULL values. -- create table with NOT NULL constraint CREATE TABLE Colleges ( college_id INT NOT NULL, college_code VARCHAR(20), college_name VARCHAR(50) ); Here, the college_id column of the Colleges table won't ...
Microsoft Learn
learn.microsoft.com › en-us › sql › t-sql › language-elements › null-and-unknown-transact-sql
NULL and UNKNOWN (Transact-SQL) - SQL Server | Microsoft Learn
For example, a customer's middle initial might not be known at the time the customer places an order. ... To test for null values in a query, use IS NULL or IS NOT NULL in the WHERE clause.
W3Schools
w3schools.com › sql › sql_ref_is_not_null.asp
SQL IS NOT NULL
SQL Examples SQL Editor SQL Quiz SQL Exercises SQL Server SQL Syllabus SQL Study Plan SQL Bootcamp SQL Training ... The IS NOT NULL command is used to test for non-empty values (NOT NULL values).
W3Schools
w3schools.com › mysql › mysql_notnull.asp
MySQL NOT NULL Constraint
To define a NOT NULL constraint when creating a table, add NOT NULL after the data type of the column name. The following SQL creates a "Persons" table, and ensures that the "ID", "LastName", and "FirstName" columns cannot accept NULL values:
Microsoft Learn
learn.microsoft.com › en-us › answers › questions › 1507095 › case-when-not-check-null-value-as-defined
Case When not check NULL value as defined - Microsoft Q&A
No two null values are equal. ... SELECT ID,Col1,Col2 ,CASE WHEN Col2 IS NULL THEN 'No Value' WHEN Col2 = 101 THEN 'AAA' WHEN Col2 = 102 THEN 'BBB' ELSE 'CCC' END AS Col3 FROM @tbl
SQL Practice
sql-practice.com
Learn SQL - Online SQL Terminal - Practice SQL Querys
Datatypes Create Table Drop Table Alter Table Constraints Not Null Unique Primary Key Foreign Key Check Default Auto Increment Index ... Start by selecting a question by pressing 'Start' or 'View All Questions'. ... Use the resources and information about the database from the left panel to help. ... Press the run button to execute the query. ... Question is automatically validated every time you execute the query.
Top answer 1 of 6
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Consider checking documentation:
NULL indicates that the value is unknown. A null value is different from an empty or zero value. No two null values are equal. Comparisons between two null values, or between a null value and any other value, return unknown because the value of each NULL is unknown.
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If you consider that the value of istrue is unknown in the NULL case then it might or might not equal 1.
The expression istrue != 1 then evaluates to unknown
SQL only returns rows where the WHERE clause evaluates to true.
If you are on SQL Server 2022+ you can use
WHERE istrue IS DISTINCT FROM 1
To give the inequality semantics that you want (Fiddle).
SQLServerCentral
sqlservercentral.com › home › topics › when null is not null
When NULL IS NOT NULL – SQLServerCentral Forums
July 25, 2013 - Microsoft SQL Server 2008 (RTM) - 10.0.1600.22 (X64) Jul 9 2008 14:17:44 Copyright (c) 1988-2008 Microsoft Corporation Developer Edition (64-bit) on Windows NT 6.1 <X64> (Build 7600: ) ... Attempting to set a non-NULL-able column's value to NULL.
Reintech
reintech.io › term › understanding-is-not-null-operator-in-sql
Understanding 'IS NOT NULL' Operator in SQL | Reintech media
In SQL, the 'IS NOT NULL' operator is used to test for non-null values. It returns true if the column value is not NULL, and false otherwise. This operator plays a significant role when you need to filter out NULL values from your query results.
Snowflake Documentation
docs.snowflake.com › en › sql-reference › functions › is-null
IS [ NOT ] NULL | Snowflake Documentation
When IS NULL is specified, the value is TRUE if the expression is NULL. Otherwise, returns FALSE. When IS NOT NULL is specified, the value is TRUE if the expression is not NULL.
Quora
quora.com › How-can-you-find-all-values-that-are-not-null-using-a-single-query-in-SQL-Server
How to find all values that are not null using a single query in SQL Server - Quora
Answer (1 of 4): We can use the below for single SELECT * FROM user WHERE username IS NOT NULL; We can use the below for multiple SELECT * FROM user WHERE username IS NOT NULL OR email IS NOT NULL OR description IS NOT NULL;
Medium
medium.com › @roscoe.kerby › sql-exploring-the-difference-between-null-and-is-not-null-33602745e60e
SQL: Exploring the Difference Between “!= NULL” and “IS NOT NULL” | by Roscoe Kerby [ROSCODE] | Medium
September 26, 2023 - Now, let’s explore the two operators in question: “!=” and “IS NOT NULL.” ... The “!=” operator, also written as “<>”, is a common comparison operator in SQL used to test for inequality between two values.
SQLServerCentral
sqlservercentral.com › home › topics › check the variable is empty or null
Check the Variable is Empty or Null – SQLServerCentral Forums
September 9, 2014 - This is because in SQL Server, the unknown/missing/null is regarded as the lowest possible value. ... NULL is not the lowest possible value; it is unknown.