You use the SQL CONNECT statement to establish a
connection to a DBEnvironment.
This statement must be executed by some type of SQL
program, such as:
Application programs you create yourself
During database access, you perform queries or
other operations that manipulate
data by inserting, deleting, or modifying rows in tables.
This process is called data manipulation.
Here is a simple query using the SELECT statement, which displays
a selection of data from the Employees table.
The asterisk indicates all columns are to be displayed:
Below is the query result:
select * from employees;
--------------+-----------+-----------
LASTNAME |FIRSTNAME |EMPNUMBER
--------------+-----------+-----------
Harrison |Gerald | 2432099
Abelson |Annette | 3510044
Stanley |Peter | 3540011
Walters |Georgia | 9124772
|
The query result is also known as a result table.
Other data manipulation statements include the SQL INSERT, UPDATE, and
DELETE statements. These let you add rows to a table, update
specific column values in existing rows, or delete rows.
Examples of data manipulation are shown in Chapter 6, "Practicing with
IMAGE/SQL Using the MusicDBE."