Let's execute the select statement in MariaDB. The following select statement fetches all rows by specifying the "id", "name", "author_id" and "price" fields of the book table.
select id, name, author_id, price from book;
Specify all fields
Use "*" to specify all fields. It's easy to specify all the fields if performance isn't a burden.
select * from book;
Display fields vertically
You can display the field name vertically by specifying "\ G" instead of ";". This is useful when you have more fields.
select * from book \ G
Extract row by specifying ID
You can use the where clause to retrieve a row by specifying the id.
select * from book where id = 3;
Extract a row by specifying a price range
Let's use the where clause to retrieve a row by specifying a price range. Get a line where the price of a book is 1000 yen or more and less than 2000 yen.
select * from book where price> = 1000 and price <2000;
Let's take out cheap books of 500 yen or less and expensive books of 5000 yen or more.
select * from book where price <= 500 or price> = 5000;
Extract lines containing Perl in the book name
Let's use like to retrieve the line that contains Perl in the name of the book. "%" Represents 0 or more arbitrary characters.
select * from book where name like'%Perl%';
To include Perl at the beginning, write as follows.
select * from book where name like'Perl%';
Output to CSV file
The method of outputting the result of the select statement to the CSV file is explained below.