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MySQL CONCAT returns NULL if any field contain NULL

stackoverflow.com

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 …

sql - CONCAT'ing NULL fields - Stack Overflow

stackoverflow.com

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?

SQL using If Not Null on a Concatenation - Stack Overflow

stackoverflow.com

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.

sql - Counting null and non-null values in a single... - Stack Overflow

stackoverflow.com

If that is correct: SELECT count(*) FROM us WHERE a IS NULL UNION ALL SELECT count(*) FROM us WHERE a IS NOT NULL.

mysql concate check not null - Stack Overflow

stackoverflow.com

I dont want to return null value, how to check not null or how to make isset cond in query …

sql - WHERE all IS NOT NULL - Stack Overflow

stackoverflow.com

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..?

MySQL 8.0 Reference Manual :: B.6.4.3 Problems with NULL Values

dev.mysql.com

mysql> SELECT NULL, 1+NULL, CONCAT('Invisible',NULL); To search for column values that are NULL, you cannot use an expr = NULL test. The following statement returns no rows, because expr = NULL is never true for any expression: Press CTRL+C to copy. mysql> SELECT * FROM my_table...

How to exclude NULL values inside CONCAT MySQL?

dba.stackexchange.com

If I have this - tadd is the Address table: … Is there a way to exclude the apt_number if it doesn't exist? I was thinking of: … But it will return only those rows with apt_number...

SQL NULL Values - IS NULL and IS NOT NULL

www.w3schools.com

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

Заметка про NULL / Хабр

habr.com

Даже выражение NULL != NULL не будет истинным, ведь нельзя однозначно сравнить одну неизвестность с другой. Кстати, ложным это выражение тоже не будет, потому что при вычислении условий Oracle не ограничивается состояниями ИСТИНА и ЛОЖЬ.

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