Head First SQL

Before we get into the details of what tables, rows, and columns are, let’s step back and look at the bigger picture. The first SQL structure you need to know about is the container that holds all your tables known as a database.

NOTE

A database is a container that holds tables and other SQL structures related to those tables.

Every time you search online, go shopping, call information, use your TiVo, make a reservation, get a speeding ticket, or buy groceries, a database is being asked for information, otherwise known as being queried.

A database contains tables.

A table is the structure inside your database that contains data, organized in columns and rows.

Remember those categories you came up with? Each category becomes a column in your table. These values might be in the same column: Single, Married, Divorced.

A table row contains all the information about one object in your table. In Greg’s new table, a row would be all the data about one person. Here’s an example of some of the data that might be in one row: John, Jackson, single, writer, jj@boards-r-us.com.

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