Oracle Apex - should I use Empty_BLOB() or null?
I am currently using Oracle Apex 5.1.2.
I created a table in the database that contains a column that can hold a BLOB data type, a column for filename, and a column for MIME type.
In my APEX application, I have a File Browse page item. The intent for this page item is to allow the end-user to attach a file to the page. This part works perfectly - the user is able to browse for a file using that item and attach it to a page and later download the file in order to view it.
The problem: I want the end-user to be able to delete the attachment if they need to and, if they'd like, attach another file in its place. My idea is to create a button and in the settings for the button set the Action to "Submit Page" and the Database Action to SQL Update Action. Then I will create a page process of type PL/SQL code and set the Server-side Condition in the settings for the process to occur when the button I created is pressed. In the PL/SQL code section of the process, it appears from the research I have done that I have one of two options:
UPDATE table_name
SET blob_column = EMPTY_BLOB()
WHERE my_id = id
OR:
UPDATE table_name
SET blob_column = null
WHERE my_id = id
I have already tried both of these options and they both work, but I don't know which option is better for what I am trying to achieve. I have tried to research this problem, but unfortunately I can't find the exact answer I am looking for. Does anyone have any recommendations?
Thank you in advance.
oracle oracle-apex oracle-apex-5 oracle-apex-5.1
asked May 11 '18 at 15:51
Katherine ReedKatherine Reed
12910
add a comment |
I am currently using Oracle Apex 5.1.2.
I created a table in the database that contains a column that can hold a BLOB data type, a column for filename, and a column for MIME type.
In my APEX application, I have a File Browse page item. The intent for this page item is to allow the end-user to attach a file to the page. This part works perfectly - the user is able to browse for a file using that item and attach it to a page and later download the file in order to view it.
The problem: I want the end-user to be able to delete the attachment if they need to and, if they'd like, attach another file in its place. My idea is to create a button and in the settings for the button set the Action to "Submit Page" and the Database Action to SQL Update Action. Then I will create a page process of type PL/SQL code and set the Server-side Condition in the settings for the process to occur when the button I created is pressed. In the PL/SQL code section of the process, it appears from the research I have done that I have one of two options:
UPDATE table_name
SET blob_column = EMPTY_BLOB()
WHERE my_id = id
OR:
UPDATE table_name
SET blob_column = null
WHERE my_id = id
I have already tried both of these options and they both work, but I don't know which option is better for what I am trying to achieve. I have tried to research this problem, but unfortunately I can't find the exact answer I am looking for. Does anyone have any recommendations?
Thank you in advance.
oracle oracle-apex oracle-apex-5 oracle-apex-5.1
asked May 11 '18 at 15:51
Katherine ReedKatherine Reed
12910
add a comment |
I am currently using Oracle Apex 5.1.2.
I created a table in the database that contains a column that can hold a BLOB data type, a column for filename, and a column for MIME type.
In my APEX application, I have a File Browse page item. The intent for this page item is to allow the end-user to attach a file to the page. This part works perfectly - the user is able to browse for a file using that item and attach it to a page and later download the file in order to view it.
The problem: I want the end-user to be able to delete the attachment if they need to and, if they'd like, attach another file in its place. My idea is to create a button and in the settings for the button set the Action to "Submit Page" and the Database Action to SQL Update Action. Then I will create a page process of type PL/SQL code and set the Server-side Condition in the settings for the process to occur when the button I created is pressed. In the PL/SQL code section of the process, it appears from the research I have done that I have one of two options:
UPDATE table_name
SET blob_column = EMPTY_BLOB()
WHERE my_id = id
OR:
UPDATE table_name
SET blob_column = null
WHERE my_id = id
I have already tried both of these options and they both work, but I don't know which option is better for what I am trying to achieve. I have tried to research this problem, but unfortunately I can't find the exact answer I am looking for. Does anyone have any recommendations?
Thank you in advance.
oracle oracle-apex oracle-apex-5 oracle-apex-5.1
asked May 11 '18 at 15:51
Katherine ReedKatherine Reed
12910
I am currently using Oracle Apex 5.1.2.
I created a table in the database that contains a column that can hold a BLOB data type, a column for filename, and a column for MIME type.
In my APEX application, I have a File Browse page item. The intent for this page item is to allow the end-user to attach a file to the page. This part works perfectly - the user is able to browse for a file using that item and attach it to a page and later download the file in order to view it.
The problem: I want the end-user to be able to delete the attachment if they need to and, if they'd like, attach another file in its place. My idea is to create a button and in the settings for the button set the Action to "Submit Page" and the Database Action to SQL Update Action. Then I will create a page process of type PL/SQL code and set the Server-side Condition in the settings for the process to occur when the button I created is pressed. In the PL/SQL code section of the process, it appears from the research I have done that I have one of two options:
UPDATE table_name
SET blob_column = EMPTY_BLOB()
WHERE my_id = id
OR:
UPDATE table_name
SET blob_column = null
WHERE my_id = id
I have already tried both of these options and they both work, but I don't know which option is better for what I am trying to achieve. I have tried to research this problem, but unfortunately I can't find the exact answer I am looking for. Does anyone have any recommendations?
Thank you in advance.
oracle oracle-apex oracle-apex-5 oracle-apex-5.1
oracle oracle-apex oracle-apex-5 oracle-apex-5.1
asked May 11 '18 at 15:51
Katherine ReedKatherine Reed
12910
asked May 11 '18 at 15:51
Katherine ReedKatherine Reed
12910
asked May 11 '18 at 15:51
Katherine ReedKatherine Reed
12910
asked May 11 '18 at 15:51
Katherine ReedKatherine Reed
12910
asked May 11 '18 at 15:51
Katherine ReedKatherine Reed
12910
12910
add a comment |
add a comment |
3 Answers
3
active
oldest
votes
The choice is a matter of opinion, since both options delete the previous attachment.
I think most people would use blob_column = null to mean "no attachment", while blob_column = empty_blob() would mean "blank file attached". So I would recommend using null, but as you said, it works fine either way.
answered May 11 '18 at 18:58
kfinitykfinity
2,9891614
Sounds great to me - thank you!
– Katherine Reed
May 12 '18 at 14:56
add a comment |
I think it depends on how you would like to test for nulls
http://nuijten.blogspot.com.au/2009/11/empty-clob-is-not-null-its-not-null.html
answered May 14 '18 at 4:14
ScottScott
1,94511420
add a comment |
If you update your blob column with empty_blob() then you have to take care while selecting records like below:
suppose you want all records where blob column has some file (useful) then you have to select like below
select * from your_table where SYS.DBMS_LOB.GETLENGTH(blob_column) > 0;
but if you update your blob column with null then you can simply write like:
select * from your_table where blob_column is not null;
answered Nov 23 '18 at 12:31
p27p27
1,35412041
add a comment |
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3 Answers
3
active
oldest
votes
3 Answers
3
active
oldest
votes
active
oldest
votes
active
oldest
votes
The choice is a matter of opinion, since both options delete the previous attachment.
I think most people would use blob_column = null to mean "no attachment", while blob_column = empty_blob() would mean "blank file attached". So I would recommend using null, but as you said, it works fine either way.
answered May 11 '18 at 18:58
kfinitykfinity
2,9891614
Sounds great to me - thank you!
– Katherine Reed
May 12 '18 at 14:56
add a comment |
The choice is a matter of opinion, since both options delete the previous attachment.
I think most people would use blob_column = null to mean "no attachment", while blob_column = empty_blob() would mean "blank file attached". So I would recommend using null, but as you said, it works fine either way.
answered May 11 '18 at 18:58
kfinitykfinity
2,9891614
Sounds great to me - thank you!
– Katherine Reed
May 12 '18 at 14:56
add a comment |
The choice is a matter of opinion, since both options delete the previous attachment.
I think most people would use blob_column = null to mean "no attachment", while blob_column = empty_blob() would mean "blank file attached". So I would recommend using null, but as you said, it works fine either way.
answered May 11 '18 at 18:58
kfinitykfinity
2,9891614
The choice is a matter of opinion, since both options delete the previous attachment.
I think most people would use blob_column = null to mean "no attachment", while blob_column = empty_blob() would mean "blank file attached". So I would recommend using null, but as you said, it works fine either way.
answered May 11 '18 at 18:58
kfinitykfinity
2,9891614
answered May 11 '18 at 18:58
kfinitykfinity
2,9891614
answered May 11 '18 at 18:58
kfinitykfinity
2,9891614
answered May 11 '18 at 18:58
kfinitykfinity
2,9891614
2,9891614
Sounds great to me - thank you!
– Katherine Reed
May 12 '18 at 14:56
add a comment |
Sounds great to me - thank you!
– Katherine Reed
May 12 '18 at 14:56
Sounds great to me - thank you!
– Katherine Reed
May 12 '18 at 14:56
Sounds great to me - thank you!
– Katherine Reed
May 12 '18 at 14:56
add a comment |
I think it depends on how you would like to test for nulls
http://nuijten.blogspot.com.au/2009/11/empty-clob-is-not-null-its-not-null.html
answered May 14 '18 at 4:14
ScottScott
1,94511420
add a comment |
I think it depends on how you would like to test for nulls
http://nuijten.blogspot.com.au/2009/11/empty-clob-is-not-null-its-not-null.html
answered May 14 '18 at 4:14
ScottScott
1,94511420
add a comment |
I think it depends on how you would like to test for nulls
http://nuijten.blogspot.com.au/2009/11/empty-clob-is-not-null-its-not-null.html
answered May 14 '18 at 4:14
ScottScott
1,94511420
I think it depends on how you would like to test for nulls
http://nuijten.blogspot.com.au/2009/11/empty-clob-is-not-null-its-not-null.html
answered May 14 '18 at 4:14
ScottScott
1,94511420
answered May 14 '18 at 4:14
ScottScott
1,94511420
answered May 14 '18 at 4:14
ScottScott
1,94511420
answered May 14 '18 at 4:14
ScottScott
1,94511420
1,94511420
add a comment |
add a comment |
If you update your blob column with empty_blob() then you have to take care while selecting records like below:
suppose you want all records where blob column has some file (useful) then you have to select like below
select * from your_table where SYS.DBMS_LOB.GETLENGTH(blob_column) > 0;
but if you update your blob column with null then you can simply write like:
select * from your_table where blob_column is not null;
answered Nov 23 '18 at 12:31
p27p27
1,35412041
add a comment |
If you update your blob column with empty_blob() then you have to take care while selecting records like below:
suppose you want all records where blob column has some file (useful) then you have to select like below
select * from your_table where SYS.DBMS_LOB.GETLENGTH(blob_column) > 0;
but if you update your blob column with null then you can simply write like:
select * from your_table where blob_column is not null;
answered Nov 23 '18 at 12:31
p27p27
1,35412041
add a comment |
If you update your blob column with empty_blob() then you have to take care while selecting records like below:
suppose you want all records where blob column has some file (useful) then you have to select like below
select * from your_table where SYS.DBMS_LOB.GETLENGTH(blob_column) > 0;
but if you update your blob column with null then you can simply write like:
select * from your_table where blob_column is not null;
answered Nov 23 '18 at 12:31
p27p27
1,35412041
If you update your blob column with empty_blob() then you have to take care while selecting records like below:
suppose you want all records where blob column has some file (useful) then you have to select like below
select * from your_table where SYS.DBMS_LOB.GETLENGTH(blob_column) > 0;
but if you update your blob column with null then you can simply write like:
select * from your_table where blob_column is not null;
answered Nov 23 '18 at 12:31
p27p27
1,35412041
answered Nov 23 '18 at 12:31
p27p27
1,35412041
answered Nov 23 '18 at 12:31
p27p27
1,35412041
answered Nov 23 '18 at 12:31
p27p27
1,35412041
1,35412041
add a comment |
add a comment |
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