I have following data in my table "devices" … I executed below query … It returns result given below … How to come out of this so that it should ignore NULL AND result should be …
select a,b,null,null from table1 union select null,null,c,d from table2 union select null,null,null,null,e,f from table3.
I have a table with three fields, FirstName, LastName and Email. Here's some dummy data: … Now, if I do: … Vitals for Joe is null, as there is a single null field. How do you overcome this behaviour?
I am bit confused with the difference when we are using … Same dataframe I am getting counts in === null but zero counts in isNull. Please help me to understand the difference. Thanks …
union all select null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null
What is the difference between … and … and why does the latter not work?
Above is two queries with their results merged by a UNION ALL clause. You will notice that the queries return different columns, one called 'departure' and one called 'arrival'.
NULL в Системах управления базами данных (СУБД) — специальное значение (псевдозначение), которое может быть записано в поле таблицы базы данных (БД). NULL соответствует понятию «пустое поле», то есть «поле, не содержащее никакого значения».
Например, SELECT 'abc' + NULL дает в результате NULL.For example, SELECT 'abc' + NULL yields NULL. Когда параметр SET CONCAT_NULL_YIELDS_NULL установлен в значение OFF, объединение значения NULL со строкой дает в результате исходную строку (значение NULL...
Note: A NULL value is different from a zero value or a field that contains spaces.