Ch. 3: An Introduction to SQL
UPDATE
The command changes a value in a table.
VALUES
The command that is used to include the specific values entered into the table.
USE
The command used to activate the default database.
DROP TABLE
The command used to delete an entire table. Enter the command, followed by the name of the table and a semicolon.
CREATE TABLE
The command used to describe the layout of a table. The command is followed by the name of the table to be created and then by the names and data types of the columns that the table contains.
SELECT
The command used to view the data in a table.
default database
The database to which all subsequent commands pertain. To activate it , execute the USE command followed by the name of the database.
statement history
A special area of memory where the most recent command you entered is stored.
CREATE DATABASE
Command used to create a database followed by the name of the database.
Structured Query Language (SQL)
One of the most popular and widely used languages for retrieving and manipulating database data.
data type
The type of data that an individual column stores.
INSERT
This command adds rows to a table.
DELETE
This command is used to remove a row from a table.
SHOW COLUMNS
This command lists all the columns in a table.
null data value (null)
This data type is used when an actual value is unknown, unavailable, or not applicable.
NOT NULL
This is a clause in a CREATE TABLE command that indicates when a column cannot contain null values.
script file
This is used to executed SQL commands without retyping them, by putting them into a .txt file and entering them as SOURCE.