Adobe 38043740 - ColdFusion Standard - Mac Development Manual page 409

DEVELOPING COLDFUSION 9 APPLICATIONS
Accessing and Using Data
SQL example
The most commonly used SQL statement in ColdFusion is the SELECT statement. The SELECT statement reads data
from a database and returns it to ColdFusion. For example, the following SQL statement reads all the records from the
employees table:
SELECT * FROM employees
You interpret this statement as "Select all rows from the table employees" where the wildcard symbol (*) corresponds
to all columns.
If you are using Dreamweaver MX 2004, Adobe Dreamweaver CS3, or HomeSite+, you can use the built-in query
builder to build SQL statements graphically by selecting the tables and records to retrieve.
In many cases, you do not want all rows from a table, but only a subset of rows. The next example returns all rows from
the employees table, where the value of the DeptID column for the row is 3:
SELECT * FROM employees WHERE DeptID=3
You interpret this statement as "Select all rows from the table employees where the DeptID is 3".
SQL also lets you specify the table columns to return. For example, instead of returning all columns in the table, you
can return a subset of columns:
SELECT LastName, FirstName FROM employees WHERE DeptID=3
You interpret this statement as "Select the columns FirstName and LastName from the table employees where the
DeptID is 3".
In addition to with reading data from a table, you can write data to a table using the SQL INSERT statement. The
following statement adds a new row to the employees table:
INSERT INTO employees(EmpID, LastName, Firstname) VALUES(51, 'Doe', 'John')
Basic SQL syntax elements
The following tables briefly describe the main SQL command elements.
Statements
A SQL statement always begins with a SQL verb. The following keywords identify commonly used SQL verbs:
Keyword Description
SELECT Retrieves the specified records.
INSERT Adds a new row.
UPDATE Changes values in the specified rows.
DELETE Removes the specified rows.
Statement clauses
Use the following keywords to refine SQL statements:
Keyword Description
FROM Names the data tables for the operation.
Last updated 1/20/2012
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