SAJJAS - Knowledgebase

If your emulator popup is too big in Eclipse; follow the steps below to reduce the size of the Android emulator Go to Run >> Run Configurations . Select your application on the left side. Click on "Target"  tab on the right panel. Scroll down to the bottom and input the following under the "Emulator launch parameters" . Enter the follow command in the additional command options text box -cpu-delay 0 -no-boot-anim -cache ./cache -scale 0.8 This reduces your emulator size by 80%, and remove boot-up Android animation.

One or more files can be concatenated and saved to a single file using the very helpful copy command available in MS-DOS. The usage of it as follows, copy <multiple file names separated by the plus(+) operator> <resulting file name > Ex: copy File1.txt+File2.txt File3.txt copy *.* File3.txt

Scalar sub query UPDATE x SET foo = (SELECT y.foo FROM y WHERE y.bar = x.bar); Scalar sub query with existential predicate UPDATE x SET foo = ( SELECT y.foo FROM y WHERE y.bar = x.bar) WHERE EXISTS ( SELECT y.foo FROM y WHERE y.bar = x.bar); Updatable view (requires foreign key from x to y) UPDATE ( SELECT x.foo AS old_foo, y.foo AS new_foo FROM x, y WHERE y.bar = x.bar) SET old_foo = new_foo; Merge Update MERGE INTO x USING (SELECT foo, bar FROM y ) y ON (y.bar = x.bar) WHEN matched THEN UPDATE SET x.foo = y.foo; Note: WHEN NOT MATCHED construct is optional

Modifying a column data type or size in Oracle is done by using the constructs below Changing the column data type: ALTER TABLE <Table name> MODIFY ( <Column Name> <New data type>) Changing the size of a column: (Assuming the previous data type of column was varchar2 with the length of 20 and it needs to be changed to 10) ALTER TABLE <Table name> MODIFY ( <Column Name> VARCHAR2(10)) Note: Text within <> indicate the parameters that need to be replaced.

Renaming a column in Oracle is done by using the construct below ALTER TABLE <Table name> RENAME COLUMN <old column name> TO <new column name> Note: Text within <> indicate the parameters that need to be replaced.

The following are the steps needs to connect to an Oracle database using SQL Plus Open command prompt - Windows > Run > cmd.exe Traverse to the path where oracle client is installed. In my case it is C:\Oracle\Ora11g_32\Client11g\bin Run the command sqlplus username/password@server