Part of the
You Can Learn SQL series.
By Ken Brown
Editor, YouCanLearnSeries.com
Updated: September 1, 2004
The Data Manipulation Language (DML) is SQL statements that operate on the
tables to retrieve, delete, insert into and update specific data.
There are four commands available in the DML that allow you to manipulate the
data in the database.
1. SELECT
2. INSERT
3. UPDATE
4. DELETE
The SELECT statement allows you to retrieve data from the database to
view or insert into another table.
The INSERT statement will place new, additional data into a table,
basically it adds a row.
The UPDATE statement gives you the ability to change data in a row or
multiple rows.
The DELETE statement is a powerful command to remove rows from a table.
You must be careful with this command so you don’t delete important data. If
you don’t qualify your DELETE statement you can remove all the rows in a table
with the push of a button.
Each of these statements has qualifiers that allow you to restrict the number
of rows returned, deleted, inserted or updated. These qualifiers depend on the
statement used. Some of these qualifiers are:
WHERE CLAUSE
GROUP BY CLAUSE
HAVING CLAUSE
ORDER BY CLAUSE
UNION OPERATOR
In review, the Data Manipulation Language represents SQL commands used to
manipulate data in a database, normally at the table level.
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