What is a database query?

A database query is a piece of code (a query) that is sent to a database in order to get information back from the database. It is used as the way of retriving the information from database

A database "query" is basically a "question" that you ask the database. The results of the query is the information that is returned by the database management system. Queries are usually constructed using SQL (structured query language) which resembles a high-level programming language.

The term 'query' means to search, to question, or to find. When you query a database, your searching for information in the database. Different query languages exist for different type of databases. MS Access uses SQL, which stands for Structured Query Language. MS Access contains Tables, Forms, and Queries. The Forms are used to enter or display the data, the Tables are where the data is saved, and the queries are used to search for specific data.

An example of an query can be this:

SELECT DISTINCT Agent FROM QAMonitoring ORDER BY Agent;

The query searches the 'Agent' field from the QAMonitoring table and sorts the list by last name. There are plenty of MS Access DB forums on the net for more info and help.

Creating a Simple Query in Microsoft Access

Have you ever wanted to combine information from multiple tables in your database in an efficient manner? Microsoft Access offers a powerful query function with an easy-to-learn interface that makes it a snap to extract exactly the information you need from your database. In this tutorial we'll explore the creation of a simple query.

In this example, as with all of our Access tutorials, we will use Access 2000 and the Northwind sample database included on the installation CD-ROM. If you're using an earlier version of Access, you may find that some of the menu choices and wizard screens are slightly different. However, the same basic principles apply to all versions of Access (as well as most database systems).

Let's explore the process step-by-step. Our goal in this tutorial is to create a query listing the names of all of our company's products, current inventory levels and the name and phone number of each product's supplier.

1. Open your database. If you haven't already installed the Northwind sample database, these instructions will assist you. Otherwise, go to the File tab, select Open and locate the Northwind database on your computer.

2. Select the queries tab. This will bring up a listing of the existing queries that Microsoft included in the sample database along with two options to create new queries.

3. Double-click on "create query by using wizard". The query wizard simplifies the creation of new queries. We'll use it in this tutorial to introduce the concept of query creation. In later tutorials we'll examine the Design view which facilitates the creation of more sophisticated queries.