content_image/871662.jpg
You can also use scripts from the mysql  prompt by using the source  command or \.  command: 

mysql> source filename ; mysql> \. filename 

See Section 4.5.1.5, “Executing SQL Statements from a Text File” , for more information. 

## 3.6 Examples of Common Queries 

Here are examples of how to solve some common problems with MySQL. 

Some of the examples use the table shop  to hold the price of each article (item number) for certain traders (dealers). Supposing that each trader has a single fixed price per article, then ( article , dealer ) is a primary key for the records. 

## 3.6.1 The Maximum Value for a Column 

Start the command-line tool mysql  and select a database: 

shell> mysql your-database-name 

To create and populate the example table, use these statements: 

CREATE TABLE shop ( article INT UNSIGNED DEFAULT ’0000’ NOT NULL, dealer CHAR(20) DEFAULT ’’ NOT NULL, price DECIMAL(16,2) DEFAULT ’0.00’ NOT NULL, PRIMARY KEY(article, dealer)); INSERT INTO shop VALUES (1,’A’,3.45),(1,’B’,3.99),(2,’A’,10.99),(3,’B’,1.45), (3,’C’,1.69),(3,’D’,1.25),(4,’D’,19.95); 

After issuing the statements, the table should have the following contents: 

SELECT * FROM shop ORDER BY article; 

<img src='content_image/871662.jpg'>

“What is the highest item number?” 

SELECT MAX(article) AS article FROM shop; +---------+ | article | +---------+ | 4 | +---------+ 

## 3.6.2 The Row Holding the Maximum of a Certain Column 

Task: Find the number, dealer, and price of the most expensive article. 

