Oracle Apex - Create Download BLOB Link in Report

This Oracle Apex tutorial shows you, how to create a download BLOB link in the interactive report.

I have the following EMPLOYEE_DOCS table, in which I have the documents stored for each employee in a BLOB column CONTENT and the field EMPLOYEE_ID is the primary key.

CREATE TABLE  "EMPLOYEE_DOCS" 
   (	"EMPLOYEE_ID" NUMBER, 
	"FILENAME" VARCHAR2(100), 
	"CONTENT" BLOB, 
	"MIMETYPE" VARCHAR2(50), 
	"CREATED_DATE" DATE, 
	 CONSTRAINT "PK_EMPDOCS" PRIMARY KEY ("EMPLOYEE_ID")
  USING INDEX  ENABLE
   )
/

Note: We should have the columns FILENAME and MIMETYPE in our table having the BLOB data so that we configure the Oracle Apex settings for the Download link. Valid Mime types are, for PDF: application/pdf, for CSV: text/csv, for image: image/jpeg. Now follow these steps to create an Interactive Report with a Download link in Oracle Apex.

Create an Interactive Report with Download Link in Oracle Apex

1. In Oracle Apex, Create an Interactive report with the following query for the above table.

select "EMPLOYEE_ID","FILENAME",sys.dbms_lob.getlength("CONTENT")"CONTENT","MIMETYPE","CREATED_DATE"from "EMPLOYEE_DOCS"

You can notice above that I have used the sys.dbms_lob.getlength() function to get the BLOB content-length instead of getting the BLOB data right away.

2. Now in Oracle Apex page designer, open the report region columns and click on the CONTENT column and set the following property settings:

Type: Download BLOB

BLOB Attributes

Table Owner: Parsing Schema
Table Name: EMPLOYEE_DOCS
BLOB Column: CONTENT
Primary Key: EMPLOYEE_ID
Mimetype Column: MIMETYPE
Filename Column: FILENAME
Last Updated Column: CREATED_DATE

Appearance

Download Text: Download
Content-Disposition: Attachment

The following is the screenshot for the above settings:

Note: The Primary Key column is a must for the above table to configure BLOB settings, if you don't have the Primary Key, then you can use the ROWID. In this case, include the ROWID column in your report query and specify the ROWID as a Primary Key in the above settings.

Save the changes and run the report to test. You will have the output as follows: