Working with queries and calculated fields.
1a. Find, modify and delete records in a table.
1. Learn how to use the Query window in Design view
2. Create, run, and save queries
3. Update data using a query datasheet
4. Create a query based on multiple tables.
5. Sort data in a query
6. Filter data in a query
7. Specify an exact match condition in a query
8. Change the font size and alternating row color in a datasheet.
9. Use a comparison operator to match a range of values
10, Use the And and Or logical operators
11. Create and format a calculated field in a query
12. Perform calculations in a query using , aggregate functions, and record
group calculations
13. Change the display of database objects in the Navigation Pane.
Important Points.
1. Updating or maintaing a database is the process of adding,
modifying, and deleting records in tables.
2. Navigation mode- selects an entire field value.
3. Editing mode - you can insert or delete characters in a
field value.
4. Find command allows you t search a table or queery
datasheet. or a form to locate a specific field value or part of a field value.
5. Delete a record- click the row selector and then click the
delete button.
6. The + is the expand indicator to display the releated
records in the subdatasheet.
7 There are two types of Queries: Select Queries and Action Queries -
Select queries do not change the data in the table whereas action queries do
change the data in the table.
8. Rules of Data Normalization - 2sd Rule - Eliminate
Redundant Data - If an attribute (field) depends on only part of a multi valued
key, remove it to a separate table.
9. When you use query by example (QBE), you give Access an
example of the information you are requesting.
10. The field list contains the fields for the table you are
querying.
11. In the design grid, you include the fields and record
selection criteria for the information you want to see.
12. Sorting is the process of rearranging records in a
specified order or sequence.
13. The sort key is the field used to determine the order of
records in the data sheet.
14. Ascending Sort - A to Z, Lowest to Highest.
15. Descending Sort - Z to A, Highest to Lowest
16. A sort key is unique if the value of the sort key for each
record is different.
17. A sort key is non unique if more than one record can have
the same value for the sort key field.
18. A filter is a set of restrictions you place on the records
in an open data sheet or form to temporarily isolate a subset of the records.
19. Autofilter enables you to quickly sort and display field
values in various ways.
20. Alternate Fill/Back Color button allow you to cange the
backgorund color of datasheet rows.
21. Filter by Selection lets you select all or part of a field
value in a data sheet or form, and then display only those records that contain
the select value in a field.
22. Filter by Form, allows you to select a value from the list
arrow that appears when you click any blank field to apply a filter that selects
only those records containing that value.
23. A comparison operator asks Access to compare the value in
the database field to the condition value and to select all the records for
which the relationship is true.
| > | greater than | A > B |
| < | less than | A < B |
| >= | greater than or equal to | A >= B |
| <= | less that or equal to | A <= B |
| = | equal to | A = B |
| <> | not | <> A |
| Between..And | between two values (inclusive) | Between 50 and 325 |
| In( ) | in a list of values | In("Hall","Seeker") |
| Like matches a pattern that includes wildcards *, ? | like "707*" |
24. An exact match occurs when the value in the
specified field must match the condition exactly in order for the record to be
included in the query results.
25. Logical Operators are used to combine two or more
conditions.
Logical Operators
AND, OR, XOR, NOT
AND
| A | B | C | Result |
| True | True | True | True |
| False | True | True | False |
| False | False | True | False |
| False | False | False | False |
OR
| A | B | C | Result |
| True | True | True | True |
| False | True | True | True |
| False | False | True | True |
| False | False | False | False |
XOR
|
A |
B | C | Result |
| True | True | True | False |
| False | True | True | True |
| False | False | True | True |
| False | False | False | False |
Not
| A | Result |
| True | False |
| False | True |
Operator Precedence used in evaluating expressions
| High | ^ | Arithmetic |
| Unary + or - | ||
| * / \ mod | ||
| + - | ||
| <, >, <=, >=, =, <> | Relational | |
| NOT | Logical | |
| AND | ||
| Low | OR and XOR |
| Aggregate Function | Determines | Data Type Supported |
| AVG | Average of field values | Autonumber,Currency, Date/Time, Number |
| Count | Number of records selected | Autonumber,Currency, Date/Time, Number, Memo, OLE,Text, Yes/No |
| Max | Highest field value | Autonumber,Currency, Date/Time, Number,Text |
| Min | Lowest field value | Autonumber, Currency, Date/Time, Number, Text |
| Sum | Total of field values | Autonumber, Currency, Date/Time, Number |
| StDev | Standard Deviation of Variance | Number, Currency |
| Var | Variance of Data | Number, Currency |
Best Practice:
Access2007 will let you convert to Access2000, 2003, or Access97. Remember that when you convert the database from 2007 to 2003, 2000 or 97, features supported by the 2007 version will not be available in the 2000 or 97 version.