There are additional features that can be set while making a Table.
If these are not changed, by default they take a certain value.
Let us learn more about them.
The following table enlists the various data types that can be used while making a table:
It sets the number of characters to be allowed for the respective data type. It also sets the range in certain data types. For Example:
Text: 0 to 255 Characters
Number: -32768 to 32767
Memo: 0 to 64000
Date: According to format
Currency: 15 digits to the left side of decimal point and 4 to the right.
It helps to set how the output is shown when the field values are displayed. For Example:
Text / Memo: (<) all characters in lower case>
(>) all characters in upper case.
Yes / No Format: True, Yes is -1 On. False, No is 0 Off
This helps to set both how the data is entered and displayed by using special formats. For Example:
9 indicates numbers/ space but no signs + ,-
? indicates optional text entry
L indicates compulsory text entry
& indicates any character or space
It indicates the label that is to appear in front of the field entry boxes that are seen when we make forms or reports. We should try and give a detailed self explanatory caption label for the field. For Example: “DOB” field name can be given a detailed caption as “Date of Birth”
It indicates the value that should get entered into the field, if we do not enter any value. When we want the field to remain blank, we should not enter any value.
It indicates the check that has to be performed when we add or change the value of a field and try to save it in the table. For Example: age > 0 is a validation rule that can be put on the field age if we enter 0 or less.
It displays a message after the validation rule is checked and does not get satisfied. If we do not enter our own text message, then Ms – Access displays it on its own. For Example: For age > 0, if Validation rule is not satisfied, we can display a message “age cannot be less than equal to 0”.
It indicates whether the entry to the field is a “must” or not. In case of “No”, blank field value is possible. “Yes” indicates that a field value must be entered.
Allow Zero Length
This feature indicates whether a null or Zero character string is allowed for the Text or Memo fields. If value is set to “Yes” then zero length string is allowed, otherwise the field must contain either a value or “NULL”.
This feature indicates whether a particular field is in a specific order or not. If Index is set at “Yes” then searching or looking for a value is easier and faster.