Creating a query object from a text file
811
Creating a query object from a text file
You can create a query object from a delimited text file by using the
cfhttp
tag and specifying
method="Get"
and the
name
attribute. This is a powerful method for processing and handling
text files. After you create the query object, you can easily reference columns in the query and
perform other ColdFusion operations on the data.
ColdFusion processes text files in the following manner:
•
You can specify a field delimiter with the
delimiter
attribute. The default is a comma.
•
If data in a field might include the delimiter character, you must surround the entire field with
the text qualifier character, which you can specify with the
textqualifier
attribute. The
default text qualifier is the double quotation mark (").
•
The
textqualifier
="" specifies that there is no text qualifier
.
If you use
textqualifier
="""" (four " marks in a row), it explicitly specifies the double quotation mark
as the text qualifier
.
•
If there is a text qualifier, you must surround all field values with the text qualifier character.
•
To include the text qualifier character in a field, use a double character. For example, if the text
qualifier is ", use "" to include a quotation mark in the field.
•
The first row of text is always interpreted as column headings, so that row is skipped. You can
override the file’s column heading names by specifying a different set of names in the
columns
attribute. You must specify a name for each column. You then use these new names in your
CFML code. However, ColdFusion never treats the first row of the file as data.
•
When duplicate column heading names are encountered, ColdFusion adds an underscore
character to the duplicate column name to make it unique. For example, if two CustomerID
columns are found, the second is renamed "CustomerID_".
To create a query from a text file:
1
Create a text file with the following content:
OrderID,OrderNum,OrderDate,ShipDate,ShipName,ShipAddress
001,001,01/01/01,01/11/01,Mr. Shipper,123 Main Street
002,002,01/01/01,01/28/01,Shipper Skipper,128 Maine Street
2
Save the file as text.txt in the myapps directory under your
web_root
.
3
Create a ColdFusion page with the following content:
<cfhttp method="Get"
url="http://127.0.0.1/myapps/text.txt"
name="juneorders"
textqualifier="">
<cfoutput query="juneorders">
OrderID: #OrderID#<br>
Order Number: #OrderNum#<br>
Order Date: #OrderDate#<br>
</cfoutput>
<!--- Now substitute different column names --->
<!--- by using the columns attribute --->
<hr>
Now using replacement column names<br>
<cfhttp method="Get"
url="http://127.0.0.1/myapps/text.txt"
name="juneorders"
Содержание COLDFUSION MX 61-DEVELOPING 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...