Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
Counting the number of non-null or nonzero columns in a MySQL table?
Use if() method for this. Let us first create a table −
mysql> create table DemoTable -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> Number1 int, -> Number2 int -> ); Query OK, 0 rows affected (1.15 sec)
Insert some records in the table using insert command −
mysql> insert into DemoTable(Number1,Number2) values(10,20); Query OK, 1 row affected (0.41 sec) mysql> insert into DemoTable(Number1,Number2) values(0,32); Query OK, 1 row affected (0.38 sec) mysql> insert into DemoTable(Number1,Number2) values(40,0); Query OK, 1 row affected (0.21 sec) mysql> insert into DemoTable(Number1,Number2) values(40,50); Query OK, 1 row affected (0.17 sec)
Display all records from the table using select statement −
mysql> select *from DemoTable;
Output
This will produce the following output −
+----+---------+---------+ | Id | Number1 | Number2 | +----+---------+---------+ | 1 | 10 | 20 | | 2 | 0 | 32 | | 3 | 40 | 0 | | 4 | 40 | 50 | +----+---------+---------+ 4 rows in set (0.00 sec)
Following is the query to count the number of non-null or non-zero columns in a table −
mysql> select *, -> if(Number1 <> 0,1,0)+if(Number2 <> 0,1,0) AS TotalCount -> from DemoTable;
Output
This will produce the following output −
+----+---------+---------+------------+ | Id | Number1 | Number2 | TotalCount | +----+---------+---------+------------+ | 1 | 10 | 20 | 2 | | 2 | 0 | 32 | 1 | | 3 | 40 | 0 | 1 | | 4 | 40 | 50 | 2 | +----+---------+---------+------------+ 4 rows in set (0.00 sec)
Updated on: 30-Jun-2020
454 Views
Advertisements