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.