Why doesn't the following code work in SQL
SELECT *
FROM DATA
WHERE VALUE != NULL;
Why doesn't the following code work in SQL
SELECT *
FROM DATA
WHERE VALUE != NULL;
we can not Compare null value with = We Special operator to compare null value in sql IS OPERATOR
SELECT *
FROM DATA
WHERE VALUE is not NULL;
Null is not any Value.Sql consider Null as Unknown/absence of data.
The condition you written is not in proper format. If you want to select not null values from your table then you can use the following command
select *from table name where column name IS NOT NULL
If should work if you replace "!=" with "IS NOT".
Because a NULL value indicates an absence of data, it doesn't make sense to compare something with a value to it with an equals operator.
You can make your SELECT statement work by setting ANSI_NULLS OFF
SET ANSI_NULLS OFF
before running the statement. You can get further information here:
The code will not work in SQL because it is not possible to test for NULL values with the following operators =, <, or <>. It is not possible to compare NULL and 0 as they are not equivalent.
You can test for NULL values using the IS NULL and IS NOT NULL operators instead.
SELECT *
FROM DATA
WHERE VALUE IS NOT NULL
Null does not contain any value. Null is neither zero nor any value. So we can't compare it using comparision operators. Instead of using '=', you should use 'IS' keyword.
SELECT * FROM DATA WHERE VALUE IS NOT NULL;