24. Parameter queries

Parameter queries are especially useful for looking up such information as activities during a specific time period. Parameters can be set in almost all types of queries, including select and action queries. You can use parameter in any field in which you can type text in the Criteria row.

To create a parameter query, start with a normal select query and, instead of entering in the Criteria row, enter the text for the prompt enclosed in brackets ([]). The text you enter becomes the prompt in the dialog box. As soon as you click Run, Enter Parameter Value appears. You enter the desired value and view the result. A crosstab query is a special type of summary query that correlates summary values between two or more sets of field values, such as types of products within certain sales regions or categories of work order costs correlated with the active supervisor. One set of facts is listed as row headings at the left of the crosstab and the other is listed as column headings across the top.

The summarized values, sums, averages, or counts are contained in the body of the crosstab.

25. Update queries

Are used to change one or more field values in many records at once. You can add criteria that screen the records to be changed, as well as update records in more than one table. Update queries can use most types of expressions to specify the update.

Append Query

When you want to add records from one or more source tables to other tables, you first decide which fields you want to append, and then locate the target table and determine which fields in the target table correspond to the fields from the source. The field values are only copied – they are not moved – to the target table.

You can append records to a table in the current database or another Access database.

26.Make-table query

The make-table query does exactly what it advertises: it makes a new table out of records from one or more tables or queries. They are useful to

• export records to another database, for example, to create a table of completed orders to send to a department which uses another system;

• export consolidated information from related tables to a nonrelational application, such as Excel or Word;

• control the information that is exported;

• use as a record source for a report of events that occurred during a specific period of time;

• start the archive table by adding the first set of records;

• replace records in an existing table with a new set.

Delete Query

Might be the most dangerous action query of all. It is reasonable to make a backup copy of all tables before you begin a delete query.

A delete query removes entire records from the table, not only the specified fields. You can remove records from a single table, multiple tables related by one-to-one, or multiple tables related one-to-many.

27. Three ways to arrange information for display or distribution

Forms are commonly used for data entry and editing, as well as viewing. You can also print data from a form or save it as a report for more customizing and printing.Reports are used primarily for distributing printed information to recipients within or outside the organisation.Report snapshots are high-fidelity versions of a report that preserve the two-dimensional layout, graphics, and other embedded objects of the report. A snapshot is stored in a separate file that can be distributed via email to recipients who do not have Access installed on their computers.Formsrecord source & graphical objects.