Query Types
A QUERY is a tool for adding, viewing, sorting, filtering, or deleting data from a table. Queries can be used to display data in forms and reports.
There are four main types of queries: Select queries, Crosstab queries, Action queries, and SQL-specific queries.
A SELECT QUERY is a query that selects records (data) from a table and returns only matching criteria (a dynaset) from the original table. A select query can also create new calculated fields and summarize data. The select query is the most commonly used type of query.
A CROSSTAB QUERY is a query that groups data into categories and presents it in a spreadsheet format using selected fields as rows and columns.
An ACTION QUERY is a query that changes or deletes data in a table. There are four types of Action queries: Update, Append, Delete, and Make-table:
1) An Update Query lets a user make global changes to data in one or more tables.
2) An Append Query adds the records in a query's dynaset (taken from one or more tables) to the end of an existing table.
3) A Delete Query deletes a group of records from a table or tables according to query specifications.
4) A Make-table Query creates a new table from the results (the dynaset) of an existing query.
An SQL-SPECIFIC QUERY can only be created through an SQL statement. There are three types of SQL-Specific queries: Union, Pass-through, and Data-definition.