1. Action queries can update, append, make new tables, or delete records in a database. 2. Before running an action query, it is important to backup the database in case the query does not generate expected results. 3. The main types of action queries are update queries, which modify existing records; append queries, which add records to a table; make-table queries, which create a new table and add records; and delete queries, which remove records from a table.

1. Actions Queries

2. Understanding Action Queries
 Action queries are a way to make corrections to
database. They can make an enormous mess of
database if used incorrectly.
 Action queries differ from select queries:
− A select query shows you data that meet your
criteria.
− An action query looks for the data that meets
your criteria, and then does something with it,
such as making changes to the data or moving
records to a new table.

3. Testing Action Queries (Carefully)
 Most importantly, before you use an action
query, make a database backup! because it may
not always generate the result you expect
(mong đợi).
 To make a backup, you can copy your .accdb
database file or File➝Save & Publish to enter
Backstage view, look in the Advanced section of
the Save Database As list Back Up Database.

4. The Action Query Family
 An update query changes the values in one or
more records.
 An append query selects one or more records,
and then adds them to an existing table.
 A make-table query selects one or more
records, and then creates a new table for them.
 A delete query deletes one or more records.

5. Update Queries
 An update query searches for some records and
then modifies them.
 Using the update query when you work on lots
of data or when you want to update multiple
fields.
 Update query makes to change multiple records
at same time.

6. Update Queries
 To Create a Update Query:
− Select Create tab  Queries  Query Design.
− Add each table you want to include in query
by selecting it and then clicking Add.
− Change query to an update query by choosing
Query Tools  Design  Query Type 
Update.
− Add the field you want to use for filtering, and
then set the Criteria box for each one.

7. Update Queries
− Add the field you want to change.
− In the Update To box, supply the new value
that your query will apply to each field.

8. Update Queries
− Add any other fields that you want to inspect
to confirm that you’re selecting the correct
records.
− Right-click the query’s tab title, and choose
Datasheet View to see the rows that query
affects.
− Now switch back to Design view, choose
Query Tools  Design  Results Run to run
update query and have Access apply your
changes.

9. Update Queries
 Access warns you about the change it’s about to
make. Click Yes to make the change.
 If you want to save your query, then press
Ctrl+S You’ll need to supply a name for your
query.

10. Append Queries
 An append query selects records from a table
and then inserts them into the end another
table.
 You may want to use an append query to
transfer records from one database to another.
This technique is handy if you have duplicate
tables in different databases.
 To transfer the records, you need to make sure
the two tables line up. (Page 255)

11. Append Queries
 Create a new query by choosing Create
Queries  Query Design.
 Using the Show Table dialog box, add the
source table that has the records you want to
copy.
 Query Tools Design ➝ Query Type ➝Append.

12. Append Queries
− Another Database: transfer the records to
another database click Browse to
select database file OK.
− Table Name box: enter the name of the table to
which you want to transfer the records.
− Click OK to close the Append or Make Table
dialog box.
− Add the field you want to copy from the
source table.

13. Append Queries
− If you’re creating an append query, then fill in
the names of the destination fields in the
Append To boxes.
− If want to copy only some of the records in the
source table, then set the filter conditions you
need.
− Choose Datasheet View to see the rows that
your query affects.

14. Append Queries
− Switch back to Design view, and then choose
Query Tools Design  Results  Run to
transfer your records.
− Press Ctrl+S to save query.

15. Make-Table Query
 The make-table query creates the destination
table, and then copies the records to it.
− Open the source database.
− Choosing Create ➝ Queries ➝ Query Design.
− Add the source table that has the records you
want to copy.
− Select Query Tools ➝ Design ➝ Query Type
➝ Make Table.

16. Make-Table Query
− Another database: transfer the records to
another Database, click Browse to select
database file  OK.
− Table Name: enter the name of the table which
you want to transfer the records.

17. Make-Table Query
− Add the field you want to copy from the
source table.
− To copy only some of the records in the source
table, then set the filter conditions.
− Choose Datasheet View to see the rows that
your query affects.
− Switch back to Design view  Results ➝ Run
to transfer the records.
− Press Ctrl + S to save query.

18. Delete Queries
 Delete queries are the simplest and most
dangerous of the action queries.
 Delete query erases records from the database.
 To create a delete query:
− Select Create tab ➝ Queries ➝ Query Design.
− Add the table that has the records you want to
delete.
− Select Query Tools Design ➝ Query Type ➝
Delete.

19. Delete Queries
− Add the fields you want to use for filtering,
and then set filter conditions.
− Add the fields that you want to inspect to
confirm you’re getting the correct records in
the datasheet view.
− Choose Datasheet View to see the rows that’ll
be affected by query.
− Switch back to Design view, choose Query
Tools  Design  Results  Run to remove
the records.