Application Programming and SQL Guide - Kmlinux

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Chapter 2. Working with tables and modifying data
Working with tables
This chapter discusses these topics:
v Creating your own tables: CREATE TABLE
v “Working with temporary tables” on page 21
v “Dropping tables: DROP TABLE” on page 25
v “Defining a view: CREATE VIEW” on page 25
v “Changing data through a view” on page 26
v “Dropping views: DROP VIEW” on page 27
v “Inserting rows: INSERT” on page 27
v “Selecting values as you insert: SELECT from INSERT” on page 31
v “Updating current values: UPDATE” on page 36
v “Deleting rows: DELETE” on page 37
See DB2 SQL Reference for more information about working with tables and data.
This section discusses how to work with tables. As you work with tables, you might
need to create new tables, copy existing tables, add columns, add or drop
referential and check constraints, drop the tables you are working with, or make any
number of changes.
Creating your own tables: CREATE TABLE
Use the CREATE TABLE statement to create a table. The following SQL statement
creates a table named PRODUCT:
CREATE TABLE PRODUCT
(SERIAL CHAR(8) NOT NULL,
DESCRIPTION VARCHAR(60) DEFAULT,
MFGCOST DECIMAL(8,2),
MFGDEPT CHAR(3),
MARKUP SMALLINT,
SALESDEPT CHAR(3),
CURDATE DATE DEFAULT);
The preceding CREATE statement has the following elements:
v CREATE TABLE, which names the table PRODUCT.
v A list of the columns that make up the table. For each column, specify the
following information:
– The column’s name (for example, SERIAL).
– The data type and length attribute (for example, CHAR(8)). For more
information about data types, see “Data types” on page 4.
– Optionally, a default value. See “Identifying defaults.”
– Optionally, a referential constraint or check constraint. See “Using referential
constraints” on page 253 and “Using check constraints” on page 251.
You must separate each column description from the next with a comma, and
enclose the entire list of column descriptions in parentheses.
Identifying defaults
If you want to constrain the input or identify the default of a column, you can use
the following values:
v NOT NULL, when the column cannot contain null values.
© Copyright IBM Corp. 1983, 2004 19