Web Database Applications with PHP, and MySQL

Inserting, Updating, and Deleting Data

The Data Manipulation Language (DML) encompasses all SQL statements used for manipulating data. There are four statements that form the DML statement set: SELECT, INSERT, DELETE, and UPDATE. We describe the last three statements in this section. While SELECT is also part of DML, we cover it in its own section, Section 3.6. Longer worked examples using all the statements can be found in the section Section 3.8.

Inserting Data

Having created a database and the accompanying tables and indexes, the next step is to insert data. Inserting a row of data into a table can follow two different approaches. We illustrate both approaches by inserting the same data for a new customer, Dimitria Marzalla.

Consider an example of the first approach using the customer table:

INSERT INTO customer 
  VALUES (NULL,'Marzalla','Dimitria', 'F','Mrs',
          '171 Titshall Cl','','','St Albans','WA',
          '7608','Australia','(618)63576028','',
          '[e-mail]','1969-11-08',35000);

In this approach a new row is created in the customer table, then the first value listed—in this case, a NULL—is inserted into the first attribute of customer. The first attribute of customer is cust_id and—because cust_id has the auto_increment modifier and this is the first row—a 1 is inserted as the cust_id. The value “Marzalla” is then inserted into the second attribute surname, “Dimitria” into firstname, and so on. The number of values inserted must be the same as the number of attributes in the ...