*queries are perhaps the most important component in a database. Queries are used to retrieve information from a database. A *query is a set of rules for finding information in a database. Queries in a database use the Structured Query Language (SQL – often pronounced “sequel”).
*queries can be created using the much simpler Query by Example (QBE) window.
* most common variety of query is the select query, where the query is used to select certain information from the database according to criteria you specify.
*select query involves the following steps:
1. Choose which table(s) the information will be coming from
2. Choose which fields will be included in the query output.
3. Specify the criteria for the type of query.
4. Run the query / view the results.
FEATURES OF THE QUERY
*originally developed by IBM in the 1970’s to help users in their retrieval of the data from the database.
Through Access QBE,we can,
*ask questions about the data held in one or more tables and to specify the fields we want to appear in the answer.
* select records according to specific or non specific criteria and perform calculations on the data help in the tables.
*We can perform useful operations on tables (deleting,inserting)
*When we create a query using QBE, in the background Microsoft Access constructs the equivalent SQL statement.
*SQL is a language used ion querying, updating and management of relational databases.
INTRODUCTION TO MICROSOFT ACCESS QUERIES
Select Quiries
*most commonly used queries
* can view analyze and make changes to the data
* view data from a single table or form multiple tables.
*dynaset –MA collects the retrieve data
*dynamic view of the data from one or more tables, selected and sorted as specified by the query
* updatable set of records defined by a table or a query that we can treat as an object.
SUMMARY OF MS ACCESS 2000 QUERY TYPES QUERY TYPE | DESCRIPTION | Select Query | Asks a question or