
448
Chapter 21: Updating Your Database
You have updated the information for
#Form.FirstName# #Form.LastName#
in the employee database.
</cfoutput>
</body>
</html>
2
Save the page.
3
View update_form.cfm in your web browser by specifying the page URL and an Employee ID;
for example, type the following:
http://localhost/myapps/update_form.cfm?Emp_ID=3.
4
Enter new values in any of the fields, and click Update Information.
ColdFusion updates the record in the Employee table with your new values and displays a
confirmation message.
When the
cfquery
tag retrieves date information from a Microsoft Access database, it displays
the date with tenths of seconds, as follows:
This example uses the
Left
function to trim the two final characters. The CompanyInfo data
source connects to company.mdb.
Reviewing the code
The following table describes the highlighted code and its function:
Deleting data
You use a
cfquery
tag with a SQL DELETE statement to delete data from a database.
ColdFusion has no
cfdelete
tag.
Deleting a single record
To delete a single record, use the table’s primary key in the WHERE condition of a SQL
DELETE statement. In the following procedure, Emp_ID is the primary key, so the SQL Delete
statement is as follows:
DELETE FROM Employee WHERE Emp_ID = #Form.Emp_ID#
You often want to see the data before you delete it. The following procedure displays the data to
be deleted by reusing the form page used to insert and update data. Any data that you enter in the
form before submitting it is not used, so you can use a table to display the record to be deleted
instead.
Code
Description
<cfquery name="UpdateEmployee"
datasource="CompanyInfo">
UPDATE Employee
SET FirstName = '#Form.Firstname#',
LastName = '#Form.LastName#',
Dept_ID = #Form.Dept_ID#,
StartDate =
'#left(Form.StartDate,19)#',
Salary = #Form.Salary#
WHERE Emp_ID = #Form.Emp_ID#
</cfquery>
Updates the specified columns in the record in
the Employee table of the CompanyInfo
database that matches the primary key (Emp_ID).
Because #Form.Dept_ID#, #Form.Salary#, and
#Form.Emp_ID# are numeric, they do not need
to be enclosed in quotation marks.
Because of the way
cfquery
gets and displays
dates from Access databases, you use the
Left
function to trim the returned value.
Содержание ColdFusion MX
Страница 1: ...Developing ColdFusion MX Applications...
Страница 22: ...22 Contents...
Страница 38: ......
Страница 52: ...52 Chapter 2 Elements of CFML...
Страница 162: ......
Страница 218: ...218 Chapter 10 Writing and Calling User Defined Functions...
Страница 250: ...250 Chapter 11 Building and Using ColdFusion Components...
Страница 264: ...264 Chapter 12 Building Custom CFXAPI Tags...
Страница 266: ......
Страница 314: ...314 Chapter 14 Handling Errors...
Страница 344: ...344 Chapter 15 Using Persistent Data and Locking...
Страница 349: ...About user security 349...
Страница 357: ...Security scenarios 357...
Страница 370: ...370 Chapter 16 Securing Applications...
Страница 388: ...388 Chapter 17 Developing Globalized Applications...
Страница 408: ...408 Chapter 18 Debugging and Troubleshooting Applications...
Страница 410: ......
Страница 426: ...426 Chapter 19 Introduction to Databases and SQL...
Страница 476: ...476 Chapter 22 Using Query of Queries...
Страница 534: ...534 Chapter 24 Building a Search Interface...
Страница 556: ...556 Chapter 25 Using Verity Search Expressions...
Страница 558: ......
Страница 582: ...582 Chapter 26 Retrieving and Formatting Data...
Страница 668: ......
Страница 734: ...734 Chapter 32 Using Web Services...
Страница 760: ...760 Chapter 33 Integrating J2EE and Java Elements in CFML Applications...
Страница 786: ...786 Chapter 34 Integrating COM and CORBA Objects in CFML Applications...
Страница 788: ......
Страница 806: ...806 Chapter 35 Sending and Receiving E Mail...