Chapter 10.1.3

6
CREATING TABLES AND
VIEWING DATA

6.1 INTRODUCTION
The database is a concept of file organization. It consists of related
files stored together so that groups of data items can be easily
retrieved. Visual FoxPro also consists of related files organized in
such a way that the user accesses groups of data easily. In Visual
FoxPro the data and information is stored in the form of Table. More
than one table can be created in a single Visual FoxPro database
with different group of data items. Visual FoxPro allows the data to
be stored, maintained, manipulated and retrieved.
6.2 OBJECTIVES
After going through this lesson you will be able to
create a table with table Wizard

create a table with table designer

open an existing table

append, edit and delete records in the table

index and sort data

Creating Tables and Viewing Data :: 71

6.3 CREATING TABLE WITH TABLE WIZARD
There are two ways of creating a Table using:
(i) Table Wizard
(ii) Table Designer
The Table Wizard allows you to create new tables based on any of
the group of typical standard tables that are in-built with Visual
FoxPro. The Table Wizard is a useful shortcut, which helps you in
creating your own table. For many applications, you need to create
a new table from the scratch, which becomes more easier using
Wizard. In this section, we will concentrate on creating table with
Table Wizard.
To create a new table by using Table Wizard, do the following:
Choose New… option from the File menu. Cerate a new database
for a specific application so that all the related components pertaining
to the application can be stored in that database. The New dialog
box for creating a fresh Table is shown in Fig. 6.1.

Fig. 6.1: Dialog Box for creating new components

72 :: Computer Applications

Select the Table radio button, and then choose Wizard. The Table
Wizard dialog box appears as shown in Fig. 6.2.

Fig. 6.2: step 1 of the Table Wizard dialog box

The Table Wizard dialog box displays a list of in-built available
standard tables designed to store related data Payments, Products,
projects, Reservations, Students and many other types of tables as
shown in the figure 6.2. You can select any one of the table according
to your requirement from the sample Table lists. For example
Students Table is considered as example in rest of the lessons.
6.3.1 Selecting Table Fields
The fields available with the selected table will be displayed in the
Available Fields list. You can select the fields to include in your
new table by using the Field Picker to move them from the Available
Fields list to the Selected Fields list as shown in the Fig. 6.3


Fig. 6.3: Step 1 of the Table Wizard dialog box

Select the required field from the Available Fields list and then
click the push button to add the selected field into the
Selected Fields list. You can also move the required field from
the Available Fields list to the Selected Fields list by simply
double clicking in it.
To add all the fields from the Available Fields to Selected Fields
list, click Push button.

Select the field from the Selected Fields list and then click
push button to remove it back from the Selected Fields list
to the Available Fields list.
To remove all the fields from the Selected Fields list back to
Available Fields list, click push button.


To change the order of an existing field to a different location in the
table, click the double-headed arrow to the left of the field you
want to move and drag the field to a new location.
You can also move an existing field by using the Keyboard. Press
<Tab> Key until the desired field is selected, then hold down the
<Ctrl> key and then press the Up and Down arrow key to drag the
field to its new location.
Click Next button, once you are through with the selecting table
and table fields. In this case we selected the Student Table and its
available fields
6.3.2 Selecting a Database
The step 1a of the Table Wizard dialog box as shown in Fig. 6.4
allows you to select a database in which you wish to add your new
table. You can create the Database as a stand alone free table. You
can also change the name of the table from what was available in
the Table Wizard from Student to School.
If a database is open you may add your new table in the existing
database.

Fig. 6.4: Step 1a of the Table Wizard dialog box


6.3.3 Modifying Table Fields Settings
After selecting the required table and the table fields from the Table
Wizard step 1 dialog box, you click Next push button and then the
step 2 of Table Wizard dialog box appears as shown in Fig. 6.5,
which allows you to modify the field settings.

Fig. 6.5: step 2 of the Table Wizard Dialog box

This dialog box allows you to change the Field Name, Caption, Type
and other attributes of the field, according to your requirement. To
modify a field, select it and specify the settings you want.
6.3.4 Indexing Table Field
An Index is an arrangement of displaying records in a certain order
of the datafield so that records can be accessed very fast. The step 3
of the Table Wizard dialog box as shown in figure 6.6 allows you to
select fields that you have included to be used as the basis of an
index, which can be used to determine the order in which the table’s
records are displayed.
If a database is open, you may select one field on the primary index


key. A primary index key contains a value that is used to uniquely
identify each record.
You can also select the check boxes to create other indexes.
To create an index tag for the table based on that field, which
lets you control the order in which the records are displayed,
click the check box to the left of the field name. An up arrow
occurs, indicating an index in ascending order.
Click the check box button again, if you want the index in
descending order.
To remove an index tag for a selected field, click the check box
to the left of the field until the button is blank.
To create a primary key with multiple fields select more than
one field.

Fig. 6.6: Step 3 of the Table Wizard dialog box

6.4 SAVING TABLE
Click Next push button, after creating an index tag for your table.


The step 4 of the Table Wizard dialog box as shown in the Fig. 6.7
allows you to save the table for later use; save table and browse it;
save table and modify it in the Table Designer.

Fig. 6.7: step 4 of the Table Wizard dialog box

Choose Finish push button. The Save As dialog box appears as
shown in the figure 6.8. You need to specify the directory where
the new file will be stored and give a file name by typing a file name
in the Name Text box and choose Save push button. Be sure that
Save As type should be same as shown in figure 6.8.

Fig. 6.8: Save As Dialog box


INTEXT QUESTIONS

1. What do you understand by Indexing?

2. In the Step 1 of creating a table with Table Wizard, you select

(a) Table and Fields (b) Table and Records

(c) Fields and Records (d) All the above

3. Primary Index Key in a table is always

(a) many (b) unique (c) double (d) null

4. True or False

(a) You can create a table only with Table Wizard.

(b) You can change the field settings in a table created with
Table Wizard.

6.5 CREATING A TABLE WITH TABLE DESIGNER

To create a new table from scratch, by using Table Designer. Choose
New… option from the File menu. The New dialog box appears as
shown in the figure 6.9. Select the Table button and then choose
New File. The Create dialog box appears as shown in the figure 6.9.
This table is identical to the Save As dialog box and is used in the
same way to specify the directory and name of the table.

You can also invoke the Create dialog box by typing the command
CREATE in the command window and then press <Enter> key.

For example, in this lesson, we will create a sample student details
Table and name it STUDENT and it will be stored automatically with
the extension DBF i.e. STUDENT.DBF (Figure 6.9)


Fig. 6.9: Create Dialog box

Click the Save button, an empty Table Designer dialog box appears
as shown in the figure 6.10.

Fig. 6.10: An empty Table Designer Dialog box


You can also invoke the empty Table Designer dialog box directly by
typing the command CREATE <table name> in the command window
and then press <Enter> key as shown in the figure 6.11

Fig. 6.11: Invoking Table Designer

6.5.1 Defining Table Fields
To define each field in the table using the Table Designer dialog
box, you should follow these steps:
1. Type a field name (which can be up to 10 characters long in a
text) below the name heading. You must note that spaces are
not allowed in the field name. The only punctuation allowed is
the underscores.
2. Open the Type popup and choose one of the data type from the
list by clicking on it. The following data types are available on
the Type popup.
Data Type Description
Character The character fields can be used to store letters,
numbers, special symbols, and blank spaces. The
maximum field width of a character field is 254.
The default width is 10.
Currency The currency fields can be used to store money
values. It holds amount from over 900 trillion to
less than -900 trillion. The default width of
currency data is 8.
Numeric The numeric fields can be used to store numbers
on which calculation can be performed. The
maximum field width of a numeric field is 20
including an optional +/- sign and decimal place.
The default width of numeric data is 8.


Float The float field is specifically designed for scientific
data. There is no difference between the numeric
and float data types. The maximum field width of
a float field is 20 including an optional +/- sign
and decimal place. The default width of float data
is 8.
Date The date fields are used to store dates. The field
width of a date type field is always 8. The default
date entry and display format is mm/dd/yy. This
can be modified to other country formats by using
the SET command.
DateTime The DateTime data type can store either a date
such as 09/23/02, a time such as 06:35:45 AM,
or a date and time such as 09/23/02 06:35:45
AM. The field width of a DateTime type field is
always 14.
Double The double data type stores numeric data, but it
does calculations with more accuracy than the
Numeric data type.
Logical The logical fields accept only single character
representing True/False values. Logical True (.T.)
can be entered as T, t, Y, or y (yes) and Logical
False can be entered as F, f, N, n (no).
Memo The memo fields may be used to store any
printable ASCII character (letters, number, blank
spaces or special symbols). All memo fields in a
database file are stored in a database memo file
with extension .dbt which is created while setting
up the database file. Memo fields are indicated
in the database (.dbf) file by the word memo.
Memo field’s sizes are limited by the amount of
memory available. Each memo field occupies only
10 spaces in the table.
General The general fields are used to store OLE (Object
Linking and Embedding) objects. A width of 10
characters is automatically assigned. The general
field’s sizes are also limited by the amount of
memory available.
Character (Binary)The Visual FoxPro’s Binary Character data may


include any 8 bit value, including the null
character. The maximum field width of a binary
character field is 254.

Memo (Binary) The Visual FoxPro’s Binary Memo fields can be
used to hold types of data that could never before
be manipulated with database management
programs, such as scanned images or digitized
sound.

3. If the data type you have chosen has a variable field width, a
spinner occurs under the heading Width. You can change the
default value by entering a width in the Width text box or by
clicking the spinner control.

4. For numeric, double or float data type, you have to specify a
value under the heading Dec for the number of decimal places
the field should have. You can enter the number by typing in
the text box or by using the spinner control.

5. The Null column determines whether you can enter a NULL
value in a field.

Based on these details you can create your own table structure
named “SCHOOL” by typing the following fields in the Table Designer
dialog box as shown in the figure 6.12.

Field Name Type Width Dec Nulls
1 ENROL Character 9
2 NAME Character 25
3 FNAME Character 25
4 COURSE Character 1
5 ADD1 Character 25
6 ADD2 Character 25
7 ADD3 Character 25
8 PIN Numeric 6


Fig. 6.12: Table designer dialog box with fields

After defining all the fields in a table structure dialog box, choose
OK button. Visual FoxPro displays a dialog box asking whether you
want to “Input data records now?” as shown in the figure 6.12.

Fig. 6.13: Input data records now?

Choose No, if you don’t want to input data now. Choose Yes to open
a Browse window for the table in Append mode, so you can right
away begin entering data into the table.
6.5.2 Inserting Table Field
To insert a new field in an existing table in the Table Designer
dialog box, position the cursor in an existing field and choose the
Insert push button. A new field appears with the name NEWFIELD
with a character type and a default width of 10 characters is added
before the selected field. Modify these as per your requirement.


6.5.3 Deleting Table Field
To remove an existing field from the Table Designer dialog box,
position the cursor to that field and choose the Delete push button.
The selected field is deleted and the fields below the deleted field
move up one position in the Table Designer dialog box.
6.6 OPENING A TABLE
Once you have created a table, you can open it at any time by using
any one of the following techniques:
Type Use <table name> in the command window and press
<Return> key. The name of the table, which you have specified
with the USE command, is displayed at the left of the status
bar. The following command will open the table STUDENT already
created.
Use STUDENT
Choose Open option from the File menu. Select the directory
and name of the table and choose OK. The name of the table is
displayed at the left of the status bar. The status bar also
indicates that it has no records, and that it is opened exclusively,
so it is not accessible to other user on a network.
6.7 APPENDING RECORDS / DATA
After opening the existing table named “STUDENT”, you can
append records in the table by using any one of the following
techniques:
Choose Append Mode option from View menu. A new blank
record is added to end of the table to enter the data in the table
named “STUDENT”.
Type append in the command window and press <Return> key.
A new blank record is added to end of the table to enter the
data in the table named “STUDENT”. The figure 6.14 shows the
example of how to enter data in the Append mode.


Fig. 6.14: Entering data in Append Mode

Now you can enter the following records, by typing it into each field
and pressing <Return> to move to the next field:
Field Values Field Values

ENROL 270823001 ENROL 270823002
NAME NEELAM NAGPAL NAME KISHORE KUMAR
FNAME DEEPAK NAGPAL FNAME PANKAJ KUMAR
COURSE 2 COURSE 2
ADD1 35,LANE NO.8 ADD1 185-A, POCKET -I
ADD2 KAILASH COLONY ADD2 DILSHAD GARDEN
ADD3 NEW DELHI ADD3 NEW DELHI
PIN 110048 PIN 110095

ENROL 270823003 ENROL 270823004
NAME SAROJ KHAN NAME MUKESH KUMAR
FNAME MOHAMMAD KHAN FNAME PANKAJ KUMAR
COURSE 2 COURSE 2
ADD1 35,LANE NO.10 ADD1 18-A, POCKET -D
ADD2 SHAHADARA ADD2 MAYUR VIHAR
PIN 110032 PIN 110093


ENROL 270823005 ENROL 270823006
NAME POONAM BANSAL NAME NARENDRA GOYAL
FNAME RAKESH BANSAL FNAME PRAKASH GOYAL
COURSE 3 COURSE 3
ADD1 123-B, POCKET - P ADD1 416/7 SECTOR - 19
ADD2 MALVIYA NAGAR ADD2 VASUNDHARA
ENCLAVE
PIN 110045 PIN 110096

After you enter the records, you can save the table with the entered
data by pressing <Ctrl> + W or <Ctrl> + <End> key.

INTEXT QUESTIONS

5. Write True or False for the following statements.
(a) The general fields are used to store objects
(b) The field name in a Table can have space also.
(c) You can not Insert or delete a field in a Table.
(d) The Logical fields accept only single character.
6. The maximum length of a field name can be of
(a) 8chr (b) 10chr (c) 15chr (d) 20chr
7. The maximum field width of a Character field is
(a) 32 (b) 64 (c) 128 (d) 254
8. Write steps for inserting a column ‘Date-of-Birthe’ in Students
Table

6.8 EDITING RECORDS / DATA
To change or edit data in the table, you need to first open the table
by using any one of the techniques mentioned above at section 6.6.
After that, choose Browse STUDENT from the view menu to display
the data. You can also invoke the edit mode by typing edit in the
command window. A Browse window in Edit mode occurs to edit
the data, as shown in the figure 6.15. Remember that the Browse
window in the edit mode allows you only to edit data.


Fig. 6.15: Browse window in Edit mode

6.8.1 Moving to the specific record
If you are having a large number of records in a table, then it will
take a long time to scroll. Visual FoxPro provides you a couple of
shortcuts to move through the table more quickly.
Choose Go to Record option from the Table menu to display the
submenu as shown in the figure 6.16. The option available with the
Go to Records options are described as follows:
Option Description
Top Allows you to move to the first record of the table
Bottom Allows you to move to the last record of the table
Next Allows you to move to the record next to the
current record. It is affected by the active index.
Previous Allows you to move to the record preceding the
current record. It is affected by the active index.
Record # Allows you to bring up the Go to Record box, as
shown in the figure 6.16(a). You can either type


the record number or use the spin controller
and then choose Go to push button.
Locate… Allows you to bring up the Expression builder
dialog box to define the Locate Record for
expression.

Fig. 6.16: Go to Submenu

Fig. 6.16(a) : Go to Record dialog box

6.8.2 Finding a Specific Text String
It is very difficult to find a specific text string, if you are having a
large number of records in a table. Visual FoxPro provides you a
shortcut to find a specific text string more quickly in your table.
Choose Find… option from the Edit menu, Visual FoxPro displays


the Find dialog box as shown in Fig. 6.17. For example, enter the
data “BANSAL” you are searching for in the Look For text box.
Click the Find Next push button from the find dialog

Fig. 6.17: Find dialog box

box. If the first value you find is not the one you required, continue
this process until you get the required one. Then click Cancel push
button to close the Find dialog box.
Click the Replace push button from the Find dialog box to enter a
value that will replace the found value.
6.8.3 Deleting Record
To delete a record just click the deletion mark box as shown in
figure 6.17 or choose Toggle Deletion Mark option from the Table
menu. Alternatively, you can press <Ctrl> + T to put the mark of
deletion at the current record.

Fig. 6.18: Deletion mark put at the 1st and 3rd record

A filled in deletion mark indicates that the record will be purged
during the next PACK command or if you choose Remove Deleted
Records option from the Table menu. Repeat the toggle command
to undelete a record.


Remember that once you use PACK command on a table, those
records marked for deletion cannot be retrieved and is physically
removed from the hard disk.
6.9 INDEXING DATA
A separate index file specifies the logical order of the records in a
table. Records are displayed and accessed in the order specified by
the controlling index expression in the index file. There are two
types of index files in Visual FoxPro:
1. Compound Index File
2. Single-Entry Index File
6.9.1 Compound Index File
The compound index file contains multiple index entries or tags.
You can have as many indexes or tags as you require depending
upon the available disk space. When the file is opened, all indexes
in a compound index file are available. The name of the compound
index file is same as the table name with the extension .CDX
6.9.2 Single -Entry Index File
The single entry index file contains a single entry. You must open
this index file and make it active for it to be updated with a table.
For example you can type the following in the command window:
Use student
Index on enrol to student
Use student index student
A table can have a number of single-entry index files. The name of
the compound index file is same as the table name with the extension
.IDX
6.9.3 Creating Indexes
To create index for STUDENT.DBF, go back to the Table Designer
dialog box and click the index tab to switch to the index definition
page as shown in the figure 6.19.


Fig. 6.19: Index definition page

The index definition began with the tag Name on the left, followed
by the index Type, the tag Expression and a Filter. To enter a new
tag, enter the name for the tag in the Name column. The name
should describe the index. If your index is based on a single field, it
is generally easiest to give it a name that is same as the field name.
The arrows to the left of the names indicate whether the index is in
ascending (up arrow) or descending (down arrow) order. To change
the direction select the row and click the button that appears beneath
the arrow. In the beginning, you accept the default index type,
which is Regular. You can also make Expressions and use Filters
while defining indexes.
6.10 DEFINING ORDER IN A TABLE
The records cannot be entered in a sorted order as you do not receive
the data in sorted order. So you have to enter the records in a
random order, but you want to view them sorted by one or more
fields.
You can use the SORT command to reorder the records in a table.
SORT takes an existing table and creates a new table sorted by a
field or a combination of fields. For example,
USE STUDENT
SORT ON NAME TO STUNAME <Ascending/Descending>


Creates a new table named “STUNAME” sorted by the student name.
Normally you do not use the SORT command as it takes more disk
space by creating new table. Indexes provides you a more effective
way to view and retrieve data from a table in an orderly manner.
Because a table can have more than one index, you can define
different indexes for different views or reports.
6.11 WHAT YOU HAVE LEARNT
In this lesson you have learned about how to create a table by using
Table Wizard and Table Designer. We also discussed about modifying
the structure of an existing table in terms of field’s name, its type
and width. You also learned how to create an Index in a table and
sort a data table.

6.12 TERMINAL QUESTIONS

1. Differenciate between Sort and Index?
2. Write the Syntax for Indexing a Table.
3. What do you understand by compound indexing?
4. Explain Null Values.
5. How to add Primary Index to a table field?
6. Write steps for Inserting a new record, editing an existing record
and moving to a particular record using the table Students.

6.13 KEY TO INTEXT QUESTIONS

1. An Indexing is an arrangement of the value to search a data
value fast.
2 (a)
3. (b)
4. (a) F
(b) F
5. (a) T (b) F (c) F (d) T
6. (b)
7. (d)
8. Open the Table ‘Students’. In View menu, choose Table
Designer. Type filed name as ‘Date-of-Birth’ and Type as
Character and Width 8.

Chapter 10.1.3

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Chapter 10.1.3