Access2013 ch10

Chapter 10

Using SQL

Microsoft

Access 2013

• Understand the SQL language and how to use it

• Change the font or font size for SQL queries

• Create SQL queries

• Include fields in SQL queries

• Include simple and compound criteria in SQL queries

• Use computed fields and built-in functions in SQL queries

• Sort the results in SQL queries

Using SQL 2

Objectives

• Use aggregate functions in SQL queries

• Group the results in SQL queries

• Join tables in SQL queries

• Use subqueries

• Compare SQL queries with Access-generated SQL

• Use INSERT, UPDATE, and DELETE queries to update a database

Using SQL 3

Objectives

Using SQL 4

Project – Using SQL

• Create a query in SQL view

• Use simple criteria in a query

• Use compound criteria in a query

• Sort results of a query

• Group results of a query

• Join tables in a query

• Use a subquery in a query

• Update data with a query

Using SQL 5

Roadmap

• Tap or click FILE on the ribbon to open the Backstage view

• Tap or click Options to display the Access Options dialog box

• Tap or click Object Designers to display the Object Designer options

• In the Query design area, tap or click the Size box arrow, and then tap or click the desired font size

• Tap or click the OK button to close the Access Options dialog box

Using SQL 6

Changing the Font Size

Using SQL 7

Changing the Font Size

• Close the Navigation Pane

• Display the CREATE tab

• Tap or click the Query Design button (CREATE tab | Queries group) to create a query

• Close the Show Table dialog box without adding any tables

• Tap or click the View arrow (QUERY TOOLS DESIGN tab | Results group) to display the View menu

• Tap or click SQL View to view the query in SQL view

Using SQL 8

Creating a New SQL Query

Using SQL 9

Creating a New SQL Query

• The basic form of SQL expressions is quite simple: SELECT-FROM-WHERE

• The command begins with a SELECT clause, which consists of the word, SELECT, followed by a list of those fields you want to include

• Next, the command contains a FROM clause, which consists of the word, FROM, followed by a list of the table or tables involved in the query

• Finally, there is an optional WHERE clause, which consists of the word, WHERE, followed by any criteria that the data you want to retrieve must satisfy

Using SQL 10

SQL Commands

Using SQL 11

SQL Commands

• Tap or click the View arrow (HOME tab | Views group) to display the View menu

• Tap or click SQL View to return to SQL view

Using SQL 12

Preparing to Enter a New SQL Query

• To include all fields, you could use the same approach as in the previous steps, that is, list each field in the table after the word, SELECT

• There is a shortcut, however. Instead of listing all the field names after SELECT, you can use the asterisk (*) symbol

Using SQL 13

Including All Fields

Using SQL 14

Including All Fields

• To restrict the records to be displayed, include the word WHERE followed by a criterion as part of the command

• If the field involved is a numeric field, you simply type the value

Using SQL 15

Using a Criterion Involving

a Numeric Field

• A simple criterion has the form: field name, comparison operator, then either another field name or a value

Using SQL 16

Simple Criteria

Using SQL 17

Using a Comparison Operator

• If the criterion involves a text field, the value must be enclosed in single quotation marks

Using SQL 18

Using a Criterion Involving a Text Field

• In most cases, the conditions in WHERE clauses involve exact matches

• The LIKE operator uses one or more wildcard characters to test for a pattern match

– One common wildcard in Access, the asterisk (*), represents any collection of characters

Using SQL 19

Using a Wildcard

Using SQL 20

Using a Wildcard

• Compound criteria are formed by connecting two or more simple criteria using AND, OR, and NOT

– When simple criteria are connected by the word AND, all the simple criteria must be true in order for the compound criterion to be true

– When simple criteria are connected by the word OR, the compound criterion will be true whenever any of the simple criteria are true

– Preceding a criterion by the word NOT reverses the truth or falsity of the original criterion

Using SQL 21

Compound Criteria

Using SQL 22

Using a Compound Criterion

Involving AND

Using SQL 23

Using a Compound Criterion

Involving OR

Using SQL 24

Using NOT in a Criterion

• Just as with queries created in Design view, you can include fields in queries that are not in the database, but that can be computed from fields that are

– Called a computed field

– Can involve addition, subtraction, multiplication, or division

• To indicate the contents of the new field (the computed field), you can name the field by following the computation with the word, AS, and then the name you want to assign the field

Using SQL 25

Using a Computed Field

Using SQL 26

Using a Computed Field

• To sort the output, you include an ORDER BY clause, which consists of the words ORDER BY followed by the sort key

Using SQL 27

Sorting

Using SQL 28

Sorting the Results on a Single Field

Using SQL 29

Sorting the Results on Multiple Fields

• To sort in descending order, you follow the name of the sort key with the DESC operator

Using SQL 30

Sorting the Results in Descending Order

• The DISTINCT operator eliminates duplicate values in the results of a query

• To use the operator, you follow the word DISTINCT with the field name in parentheses

Using SQL 31

Omitting Duplicates When Sorting

• SQL has built-in functions, also called aggregate functions, to perform various calculations

– COUNT

– SUM

– AVG

– MAX

– MIN

Using SQL 32

Using a Built-In Function

Using SQL 33

Using a Built-In Function

• You can assign a name to the results of a function

• To do so, follow the expression for the function with the word AS and then the name to be assigned to the result

Using SQL 34

Assigning a Name to the Results

of a Function

Using SQL 35

Using Multiple Functions

in the Same Command

• Grouping means creating groups of records that share some common characteristic

• When you group rows, any calculations indicated in the SELECT command are performed for the entire group

– GROUP BY clause

Using SQL 36

Using Grouping

Using SQL 37

Using Grouping

Using SQL 38

Using Grouping

• The HAVING clause, which consists of the word HAVING followed by a criterion, is used to restrict the groups to be included

Using SQL 39

Restricting the Groups that Appear

• Many queries require data from more than one table

Using SQL 40

Joining Tables

• You can restrict the records to be included in a join by creating a compound criterion

Using SQL 41

Restricting the Records in a Join

• When tables appear in the FROM clause, you can give each table an alias, or an alternative name, that you can use in the rest of the statement

Using SQL 42

Aliases

Using SQL 43

Joining a Table to Itself

Using SQL 44

Joining a Table to Itself

• A subquery is a query within another query

Using SQL 45

Subqueries

• You can add records to a table using the SQL INSERT command

• The command consists of the words INSERT INTO followed by the name of the table into which the record is to be inserted

• Next is the word VALUE followed by the values for the fields in the record

– Values for Text fields must be enclosed within quotation marks

Using SQL 46

Using an INSERT Command

Using SQL 47

Using an INSERT Command

• You can update records in SQL by using the UPDATE command

• The command consists of UPDATE, followed by the name of the table in which records are to be updated

• Next, the command contains one or more SET clauses, which consist of the word SET, followed by a field to be updated, an equal sign, and the new value

Using SQL 48

Using an UPDATE Command

Using SQL 49

Using an UPDATE Command

• You can delete records in SQL using the DELETE command

• The command consists of DELETE FROM, followed by the name of the table from which records are to be deleted

• Finally, you include a WHERE clause to specify the criteria

Using SQL 50

Using a DELETE Command

Using SQL 51

Using a DELETE Command

• Understand the SQL language and how to use it

• Change the font or font size for SQL queries

• Create SQL queries

• Include fields in SQL queries

• Include simple and compound criteria in SQL queries

• Use computed fields and built-in functions in SQL queries

• Sort the results in SQL queries

Using SQL 52

Chapter Summary

• Use aggregate functions in SQL queries

• Group the results in SQL queries

• Join tables in SQL queries

• Use subqueries

• Compare SQL queries with Access-generated SQL

• Use INSERT, UPDATE, and DELETE queries to update a database

Using SQL 53

Chapter Summary

Chapter 10 Complete

Microsoft

Access 2013