Lesson 1
Refining Access Queries
Queries are an intricate part of Access, and they allow you to get just about any view of your data you need, as well as handle operations such as adding, deleting, and updating multiple records at a time. The real trick to using queries effectively is to make sure you use the correct query for the job you need to perform.
For instance, if you use an Update query when you are trying to delete information, then the query will not perform the task at hand.
This module is about showing you where and how to use the various types of queries for tasks. By the end of this module, you will know how to:
- Use Filter by Selection and Filter by Form while in a querys datasheet
- Use a parameter with your query to specify criteria dynamically
- Use multiple criteria in a query using the AND and OR operators
- Set properties for fields in queries
- Identify fields you can index to improve query performance
- Identify the three different types of joins available and how they can be used
- Discuss the different types of queries and where you would use them
- Create action queries to perform bulk operations
- Work with a Totals query to present group totals
- Explain what Crosstab queries are and how to create them
Queries are fundamental to Microsoft Access
Queries are fundamental to Microsoft Access and play a crucial role in database management. They serve multiple essential functions:
- Data Retrieval and Viewing: Queries allow you to extract specific data from one or more tables, enabling you to view information that meets certain criteria. This is vital for analyzing data and making informed decisions.
- Data Manipulation: With action queries, you can add, update, or delete multiple records simultaneously. This capability is important for maintaining data integrity and efficiently managing large datasets.
- Data Transformation: Queries can perform calculations, combine fields, and manipulate data formats, helping to prepare data for reports or further analysis.
- Reporting and Analysis: Queries often serve as the data source for forms and reports, providing customized views that highlight relevant information.
Given these critical functions, I would rank queries as **one of the most important components** in Microsoft Access. They are integral to virtually every operation you perform within the database, bridging the gap between raw data storage and meaningful information retrieval.
Select Query
A select query is a type of database object that shows information in Datasheet view.
A query can get its data from one or more tables, from existing queries, or from a combination of the two.
The tables or queries from which a query gets its data are referred to as its recordsource.
Whether you create simple select queries by using a wizard or by working in Design view, the steps are essentially the same. You choose the recordsource that you want to use and the fields that you want to include in the query, and, optionally, you specify criteria to refine the results.
After you have created a select query, you run it to see the results. Running a select query is simple ,
you just open it in Datasheet view. You can then reuse it whenever you need, for example, as a recordsource for a form, report, or another query.
In the next lesson, you will learn how to use Filter by Selection and Filter by Form while in a query's datasheet.