1 / 5

Introduction to Database Querying: Understanding Queries and SQL in CSE 2111

In this lecture for CSE 2111, we explore the concept of database querying. A database query is a request for information from a database, allowing users to extract and manipulate data. We discuss criteria and conditions that define which records to retrieve from the database. The Query By Example (QBE) Grid, available in MS Access 2010, provides a user-friendly interface to create queries. Additionally, we introduce Structured Query Language (SQL), which is used to interact with databases, including how SQL is generated from the QBE Grid.

ping
Télécharger la présentation

Introduction to Database Querying: Understanding Queries and SQL in CSE 2111

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Computer Science & Engineering 2111 CSE 2111 Lecture Querying a Database CSE 2111 Lecture- Querying a Database

  2. What is a Database Query? • A request for information from a database • To extract information from the Database you must use a Query which is a “question” or “request” • Criterion • An expression that tells the DBMS which records to retrieve • Make up of conditions • Can be one conditions or many • When you run the query a dynaset, or subset of the database is displayed. • You can make changes to this dynaset and the changes will be reflected in your database, because the dynaset is just a view of your database. CSE 2111 Lecture- Querying a Database

  3. Query By Example (QBE) Grid Dynaset created when Query is run CSE 2111 Lecture- Querying a Database

  4. Structured Query Language (SQL) • SQL is the language you use to talk to the database • MS Access 2010 supplies a graphical user interface (GUI) called the Query By Example Grid or (QBE) grid • MS Access 2010 creates the SQL for you. CSE 2111 Lecture- Querying a Database

  5. SQL Created from QBE Grid CSE 2111 Lecture- Querying a Database

More Related