Monday, November 15, 2010

Oracle: Could not find the main class

I try to install oracle instance client which is downloaded from the following link: http://www.oracle.com/technetwork/topics/dotnet/utilsoft-086879.html.

After downloading this file,
I just click the icon to install the software. Then, an error message is shown as below:



The problem is raised by downloading a corrupted file and the solution is just to download it again from oracle website in order to replace the corrupted file.

Tuesday, August 31, 2010

Oracle: single quote in string

Apostrophe/single quote at start of string

When the apostrophe/single quote is at the start of the string, you need to enter 3 single quotes for Oracle to display a quote symbol. For example:
SELECT '''Hi There'
FROM dual;
would return
'Hi There


Apostrophe/single quote in the middle of a string

When the apostrophe/single quote is in the middle of the string, you need to enter 2 single quotes for Oracle to display a quote symbol. For example:
SELECT 'He''s always the first to arrive'
FROM dual;
would return
He's always the first to arrive


Apostrophe/single quote at the end of a string

When the apostrophe/single quote is at the end of a string, you need to enter 3 single quotes for Oracle to display a quote symbol. For example:
SELECT 'Smiths'''
FROM dual;
would return
Smiths'


Apostrophe/single quote in a concatenated string

If you were to concatenate an apostrophe/single quote in a string, you need to enter 4 single quotes for Oracle to display a quote symbol. For example:
SELECT 'There' || '''' || 's Henry'
FROM dual;
would return
There's Henry


Reference: http://www.techonthenet.com/oracle/questions/quotes.php