So far we’ve learnt how to select data from a database table and how to insert and update data into a database table. Now it’s time to learn how to remove data from a database. Here comes the SQL DELETE statement!
The SQL DELETE command has the following generic SQL syntax:
DELETE FROM Table1
WHERE Some_Column = Some_Value
If you skip the SQL WHERE clause when executing SQL DELETE expression, then all the data in the specified table will be deleted. The following SQL statement will delete all the data from our Customers table and we’ll end up with completely empty table:
DELETE FROM Table1
If you specify a WHERE clause in your SQL DELETE statement, only the table rows satisfying the WHERE criteria will be deleted:
DELETE FROM Customers
WHERE LastName = 'Smith'
The SQL query above will delete all database rows having LastName 'Smith' and will leave the Customers table in the following state:
FirstName LastName Email DOB Phone
Steven Goldfish goldfish@fishhere.net 4/4/1974 323 455-4545
Paula Brown pb@herowndomain.org 5/24/1978 416 323-3232
Popular Posts
-
The SQL ORDER BY clause comes in handy when you want to sort your SQL result sets by some column(s). For example if you want to select all t...
-
STRINGS: The way a group of integers can be stored in an integer array, similarly a group of characters can be stored in a character array. ...
-
Introduction: In this exercise, you are going to build and run a sample Java program called Homework using NetBeans. The sample program can...
-
SQL aliases can be used with database tables and with database table columns, depending on task you are performing. SQL column aliases are u...
-
Declaration of variables In order to use a variable in C++, we must first declare it specifying which data type we want it to be. The syntax...
-
1 Introducing the .NET Framework with C# The .NET Framework is such a comprehensive platform that it can be a little difficult to descr...
-
More About Ascii How can I know what is the Ascii value of a specific character? Use the Asc command. For example, the following line: Print...
-
Java Server Pages JavaServer Pages (JSP) technology is the Java platform technology for delivering dynamic content to web clients in a por...
-
A JSP expression is used to insert Java values directly into the output. It has the following form: The Java expression is evaluated, conver...
-
To whom is this tutorial directed? This tutorial is for those people who want to learn programming in C++ and do not necessarily have any pr...
No comments:
Post a Comment