Learning Mysql
CHAPTER 8Doing More with MySQL
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- Inserting Data Using Queries
| CHAPTER 8 Doing More with MySQL MySQL is feature-rich. Over the past three chapters, you’ve seen the wide variety of techniques that can be used to query, modify, and manage data. However, there’s still much more that MySQL can do, and some of those additional features are the subject of this chapter. In this chapter, you’ll learn how to Insert data into a database from other sources, including with queries and from text files Perform updates and deletes using multiple tables in a single statement Replace data Use MySQL functions in queries to meet more complex information needs Analyze queries using the EXPLAIN statement and then improve their performance with simple optimization techniques Inserting Data Using Queries Much of the time, you’ll create tables using data from another source. The examples you’ve seen so far in Chapter 5 therefore illustrate only part of the problem they show you how to insert data that’s already in the form you want—that is, formatted as an SQL INSERT statement. The other ways to insert data include using SQL SELECT state- ments on other tables or databases, and reading in files from other sources. This section shows you how to tackle the former method of inserting data you’ll learn how to insert data from a file of comma-separated values in the next section, Loading Data from Comma-Delimited Files.” Suppose you’ve decided to create anew table in the music database. It’s going to store a shuffle list, tracks that are randomly selected from your music collection, put into a list, and played to you in that order. It’s away of tasting part of the collection, rediscovering some old favorites and learning about hidden treasures in those albums you haven’t explored. We’ve decided to structure the table as follows: 277 mysql> CREATE TABLE shuffle ( -> artist_id SMALLINT(5) NOT NULL DEFAULT 0, Download 4.24 Mb. Share with your friends:
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