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 …
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 dont want to return null value, how to check not null or how to make isset cond in query …
If I have the table … This will display Firstname-Middlename-Surname e.g. … The second one (Jane’s) displays correct, however since John doesn’t have a middlename, I want it to ignore the second dash.
select a,b,null,null from table1 union select null,null,c,d from table2 union select null,null,null,null,e,f
How can I run a MySQL query that selects everything that is not null? It would be something like … Do I just remove the all and go..?
Специальное значение NULL означает отсутствие данных, констатацию того факта, что значение неизвестно. По умолчанию это значение могут принимать столбцы и переменные любых типов, если только на них не наложено ограничение NOT NULL.
An expression that contains NULL always produces a NULL value unless otherwise indicated in the documentation for the operators and functions involved in the expression. All columns in the following example return NULL: Press CTRL+C to copy. mysql> SELECT NULL, 1+NULL, CONCAT('Invisible'...
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...
A field with a NULL value is a field with no value. If a field in a table is optional, it is possible to insert a new record or update a record without adding a value to this field.