Thinking in a Simple Way

搭好梯子再上来 https://simpleface.wordpress.com

The differences between DDL and DML in database(SQL)


DDL
Data Definition Language (DDL) statements are used to define the database structure or schema. Some examples:

  • CREATE – to create objects in the database
  • ALTER – alters the structure of the database
  • DROP – delete objects from the database
  • TRUNCATE – remove all records from a table, including all spaces allocated for the records are removed
  • COMMENT – add comments to the data dictionary
  • RENAME – rename an object

DML
Data Manipulation Language (DML) statements are used for managing data within schema objects. Some examples:

  • SELECT – retrieve data from the a database
  • INSERT – insert data into a table
  • UPDATE – updates existing data within a table
  • DELETE – deletes all records from a table, the space for the records remain
  • MERGE – UPSERT operation (insert or update)
  • CALL – call a PL/SQL or Java subprogram
  • EXPLAIN PLAN – explain access path to data
  • LOCK TABLE – control concurrency
Advertisements

2 responses to “The differences between DDL and DML in database(SQL)

  1. coffe November 5, 2011 at 9:33 PM

    I Just want to know if it is automatically posted the comments

  2. ashikur rahman October 8, 2013 at 2:18 PM

    many thanks to provide it

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: