User names and tablespace names

Select all schema user names

select username from dba_users;

Select all tablespace names

select tablespace_name from dba_tablespaces;

Create a simple tablespace

CREATE TABLESPACE POOL_TS
  DATAFILE 'pool_ts.dat'
  SIZE 20M AUTOEXTEND ON;

Oracle append string to select query

Append in a select statement can be achieved via the || operator.

select 'Mr.' || name from employee e where e.sex = 'M'

select case when e.sex = 'M' then 'Mr.' else 'Ms.' end || name as salutation_name from employee e

Unlock account in Oracle Database (ORA-28000)

An oracle database account can get locked for several reasons. The most common reason is number of unsuccessful attempts. This typically give the following error :

ORA-28000: the account is locked

Account can be unlocked by logging in as 'sys' user and issuing the following command:

SQL> alter user scott identified by tiger account unlock;

TimeZone in Oracle

Thread: How to Change Time Zone in 10g
want to change dbtimezone in Oracle9i
We're entering the Oracle Time Zone

Oracle decode

The Oracle decode function

Select MAX row from a table

The article groupwise max explains several ways of achieving it.

Remote Debug PL/SQL using SQL Developer

Below is a comprehensive article on how to remotely debug Pl/Sql.
Remote Debugging with SQL Developer

MySQL convert or cast int to string

Suppose you have a table with 2 columns one int and other varchar. Now if you want to update varchar fields in all the records with the int value, use this query :

update table_name set varchar_Field = CAST(int_Field AS CHAR);

If you want to some text in addition to the int field, then use :

update table_name set varchar_Field = CONCAT(CAST(int_Field AS CHAR), 'sampleText');

Install of MySQL/PHPMyAdmin aka LAMP (Linux Apache MySQL PHP)

• sudo apt-get install mysql-server
• sudo apt-get install apache2
• sudo apt-get install php5
• sudo apt-get install php5-mysql
• sudo apt-get install phpmyadmin

More information is available at the this link

Here is the link giving step by step instructions for getting mysql/apache/php and phpmyadmin working. Tells you how to set up mysql user too.

Python MySQL library support

Try the following at the python prompt.

>>> import _mysql
If the error is something like this :
Traceback (most recent call last):
    File "", line 1, in
        ImportError: No module named _mysql

Then try apt-get install python-mysqldb

How to modify Oracle LOBS/BLOBS/CLOBS

To modify a LOB,
SELECT id, blob FROM test FOR UPDATE

Note that you must use "FOR UPDATE" in the select statement or you will receive "ORA-22920: row containing the LOB value is not locked" when writing to the LOB.

The above lines are taken from the below link :
How to use Oracle LOBS/BLOBS/CLOBS