PHP and MySQL Web Development 4th Ed-tqw-_darksiderg

244 Chapter 10 Working with Your MySQL Database
There’s an ANSI standard for SQL, and database systems such as MySQL generally
strive to implement this standard.There are some subtle differences between standard
SQL and MySQL’s SQL. Some of these differences are planned to become standard in
future versions of MySQL, and some are deliberate differences.We point out the more
important ones as we go. A complete list of the differences between MySQL’s SQL and
ANSI SQL in any given version can be found in the MySQL online manual.You can
find this page at this URL and in many other locations http://dev.mysql.com/doc/
refman/5.1/en/compatibility.html.
You might have heard the terms Data Definition Language (DDL), used for defining
databases, and Data Manipulation Language (DML), used for querying databases. SQL covers
both of these bases. In Chapter 9, we looked at data definition (DDL) in SQL, so
we’ve already been using it a little.You use DDL when you’re initially setting up a database.
You will use the DML aspects of SQL far more frequently because these are the parts
that you use to store and retrieve real data in a database.
Inserting Data into the Database
Before you can do a lot with a database, you need to store some data in it.The way you
most commonly do this is to use the SQL INSERT statement.
Recall that RDBMSs contain tables, which in turn contain rows of data organized
into columns. Each row in a table normally describes some real-world object or relationship,
and the column values for that row store information about the real-world object.
You can use the INSERT statement to put rows of data into the database.
The usual form of an INSERT statement is
INSERT [INTO] table [(column1, column2, column3,...)] VALUES
(value1, value2, value3,...);
For example, to insert a record into Book-O-Rama’s customers table, you could type
insert into customers values
(NULL, 'Julie Smith', '25 Oak Street', 'Airport West');’’’
You can see that we’ve replaced table with the name of the actual table where we want
to put the data and the values with specific values.The values in this example are all
enclosed in quotation marks. Strings should always be enclosed in pairs of single or double
quotation marks in MySQL. (We use both in this book.) Numbers and dates do not
need quotes.
There are a few interesting things to note about the INSERT statement.The values
specified here will be used to fill in the table columns in order. If you want to fill in only
some of the columns, or if you want to specify them in a different order, you can list the
specific columns in the columns part of the statement. For example,
insert into customers (name, city) values
(‘Melissa Jones’, ‘Nar Nar Goon North’);