Databases Reference
In-Depth Information
Plan ahead when using the Declarative BLOBs feature. At design time, include these columns in tables that will
use declarative BLOBs:
•
FILENAME
: Stores the actual file name that is used when a user downloads the file
•
MIME_TYPE
: Stores the type of the file so browsers know which application to launch
(Word for
.doc
, Excel for
.xls
, and so on)
•
LAST_UPDATED
: Stores the date the BLOB was last updated
•
CHARACTER_SET
: Stores the character set of the BLOB, which is essential for indexing and
processing data that resides within the BLOB
The first two columns are essential for reading data out of the BLOB when needed. APEX uses the Number/Date
format column attribute of the BLOB column to map these attributes to the BLOB column stored in the database.
If you add a BLOB column after creating a report or form using a wizard, you have to manually set the column or
item properties to integrate BLOB processing.
Because you added a BLOB column to the
TICKET_DETAILS
table when you ran the SQL script, some things have
been done for you. But you still need to do several things to use declarative BLOBs properly. First, you have to map the
FILE_NAME
and
MIME_TYPE
columns to the form that is used to upload the document, so these details are saved in the
database. Let's address the form on page 220 first:
1.
Edit
Page 220
of the application.
2.
Edit the item
P220_ATTACHMENT
. In the Settings section, you see the fields
shown in Figure
6-75
.
Figure 6-75.
Specifying BLOB settings
In the
Settings
region, enter
MIME_TYPE
for
MIME Type Column
,
FILE_NAME
for
Filename
Column
, and
Download
for
Download Link Text
.
3.
4.
Click
Apply Changes
.
Next, alter the report on page 210:
1.
Edit
Page 210
of the application.
2.
Edit the
Ticket Details
region by double-clicking its name.
3.
In the
Tasks
region, click
Convert to SQL Query
. When prompted, confirm your action by
clicking
OK
.
