Queries
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Queries allow users to filter and extract specific information from one or more tables in a database. Queries can be saved and reused, unlike filters which are one-time tools. Queries use comparison operators like equal to, greater than, less than, and not equal to along with conditional operators like AND and OR to precisely select and organize data from tables.
Queries
- 1. Queries Objective 5.02 Understand queries, forms, and reports used in business.
- 2. Database Objects Objective 5.01 discussed and explained how tables are the building blocks for all databases. This objective will use tables to create three types of database objects: Queries Forms Reports
- 3. Query A query takes a database filter to the next level It is created by placing filters and selecting multiple criteria (comparison operators) to extract information from one or more tables The resulting data becomes an object and can be saved, recalled, and used to perform other operations
- 4. Advantages of a Query A query can be saved and used to perform other operations. One table can be associated with multiple queries. A query can perform specialized operations, such as performing calculations on field values, and place the results in a new column of a datasheet.
- 5. The Difference Between Queries and Filters A filter is a one-time deal. It allows application of a set of selection criteria and/or sorting instructions to the records in a table. It is a quick and temporary tool that is created for one-time use in the context of a particular table. A query is reusable . It allows the selection criteria and/or sorting instructions to be saved and reused.
- 6. Comparison Operators for Queries and Filters = Equal To > Greater Than < Less Than <> Not Equal To >= Greater Than or Equal To <= Less Than or Equal To
- 7. Conditional Operators for Queries and Filters The AND condition reduces the number of records because both conditions must be met. The OR condition increases the number of records because records are selected if either condition is met.