MACROMEDIA COLDFUSION MX 61-DEVELOPING COLDFUSION MX, Develop Manual

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418 Chapter 19: Introduction to Databases and SQL
Reading data from a database
You use the SQL SELECT statement to read data from a database. The SQL statement has the
following general syntax:
SELECT column_names
FROM table_names
[ WHERE search_condition ]
[ GROUP BY group_expression ] [HAVING condition ]
[ ORDER BY order_condition [ ASC | DESC ] ]
The statements in square brackets are optional.
Note: There are additional options to SELECT depending on your database. For a complete syntax
description for SELECT, see the product documentation.
This section describes options to the SELECT statement.
Results of a SELECT statement
When the database processes a SELECT statement, it returns a record set containing the requested
data. The format of a record set is a table with rows and columns. For example, if you write the
following query:
SELECT * FROM employees WHERE DeptID=3
The query returns the following table:
Since the data returned to ColdFusion MX by a SELECT statement is in the form of a database
table, ColdFusion MX lets you write a SQL query on the returned results. This functionality is
called
query of queries . For more information on query of queries, see Chapter 20, “Accessing and
Retrieving Data,” on page 427 .
The next example uses a SELECT statement to return only a specific set of columns from a table:
SELECT LastName, FirstName FROM employees WHERE DeptID=3
The query returns the following table: