| A string is text made of a readable letter, a symbol, a word or a group of words. When working on a table in the Datasheet View, to create a Text-based field, on the table, click Click to Add and select Text. If some columns exist already, to insert a text-based field between two columns, click the column header, or a cell under the column, that will precede it. On the Ribbon, click Fields. In the Add & Delete section, click Text  . |
If a column has been created already and it is using a data type other than text, to change it, click its column header or a cell under its column. On the Ribbon, click Fields. In the Formatting section, click the arrow of the Data Type combo box and select Text
If you are creating the table in Design View, to configure a field that can hold any type of string, specify its Data Type as Text:
A Text data type allows the user to type any kind of characters or group of characters. This field can hold up to 255 characters.
Practical Learning: Introducing Strings |
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- Start Microsoft Access
- To create a new database, click the contents of the File Name text and type Real Estate2
- Click Create
- Double-click ID, type PropertyID, and press Enter
- Double-click Add New Item and type Property #
- Right-click the Table1 tab and click Save
- Set the name to Properties and click OK
- Right-click the tab and click Design View
- Complete the list of fields with the following
Field Name | Default Value |
PropertyID | |
Property # | |
Property Type | Unknown |
Condition | Unknown |
Address | |
City | |
State | |
ZIP Code | |
- Save the table
The size of a string is usually considered as the number of characters it contains or may hold. If you have just created a Text-based field, whether in the Datasheet View or Design View, its default size is automatically set to 255 characters. This default value is too long in most cases (in some previous versions of Microsoft Access, the default size was 50). In some circumstances, you may need to set a different value. You can therefore decrease or increase this size for any number between 1 and 255:
To change the allowable number of characters of a Text-based field:
- If you are working in the Datasheet View, on the Ribbon, click Fields. In the Properties section, click Field Size and change the value:
- If you are working in the Design View, in the top section, click the name, data type, or description of the column. To specify the maximum number of characters that a Text column can contain, in the lower section of the table, click Field Size and type the desired number.
When setting the Field Size property by itself, the database would make sure that the user can only type so many characters. For example, it is very unlikely to have a first name of a person that is 50 characters. In this case, you can safely reduce the number of characters to 20 or 30. On the other hand, if you are creating a field whose length is hard to predict, you can set the length to a reasonable value. There are other ways you can decrease the number of characters that are allowed in a field. Over all, you should be able to predict the types of values that would be entered in the field.
Practical Learning: Setting Field Sizes |
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- In the upper section of the view, click Property # and press F6 to move the caret to the lower section of the view
- As the caret is on the Field Size field, type 10
- In the top section of the table, click Property Type
- In the lower section of the table, click Field Size and type 40
- Set the other field sizes as follows:
Field Name | Field Size |
Property # | 10 |
Property Type | 40 |
Condition | 40 |
Address | 100 |
City | 50 |
State | 2 |
ZIP Code | 16 |
- Save the table
- To change the view, in the Design tab of the Ribbon, click the View button

- Enter the following records:
Address | City | State |
1640 Lombardo Ave | Silver Spring | MD |
10315 Hacht Rd | College Park | MD |
6366 Lolita Drive | Laurel | MD |
9002 Palasko Hwy | Falls Church | VA |
- Right-click the tab of the table and click Design View
If a control has been created already, when performing an operation on it, you may want to know how many characters it has. To support this operation, Microsoft Access provides the Len() function. Its syntax is:
Number Len(String)
When calling this function, pass a string in between double-quotes or the name of a control. The function then produces the number of characters in it.
Creating a String in an Expression |
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A string can be treated as a constant value. As such, it can be passed to a function. However you use a string, if you already know its value, you must include it in double-quotes. Examples are "@", "Q", "Validating", "Cross Over". You can also assign a string to a control. To do this, access the Property Sheet of the control and, in its Control Source, type = followed by the string inside double-quotes.
Because users can be tempted or distracted to enter just anything in a Text-based field, Microsoft Access provides techniques to control what goes in a field and what must be prevented. This is the role of a mask. A mask is a technique of creating sections, also called placeholders, in a field. A section can be configured to accept only a letter, only a digit, a character or a digit, any symbol, nothing, or to display a particular character that the user cannot change. When creating the mask, you will use some predefined characters and create a combination of your choice.
Before creating a mask for a field, Microsoft Access comes with various masks you can apply to a field to control the user's input such as dates, times, US Social Security Number, Currency values, etc. To apply one of these masks, you can use the Input Mask Wizard. To do this, open the table in Design View. In the top section, click a column. Set its
Data Type to
Text. In the lower section of the table, click the
Input Mask property and click its ellipsis button

. This would start the wizard.
The first page of the wizard displays the most regularly used masks, including those for US/Canada telephone number, US Social Security #, US ZIP code, date, time, etc:
If you see a mask that suits you, you can check it by clicking the Try It text box. This would show the placeholders for the sections of characters that could be entered during data entry:
If you see a mask you want to use, you can click it and click Next. If none of the masks suits your need, you can create a new one and add it to the list. To do this, you would click the Edit List button. This would bring the Customize Input Mask Wizard dialog box:
By default, the Customize Input Mask Wizard offers four already created masks, including US/Canada phone number, US Social Security Number, US ZIP Code, and telephone extension number. You can check them by click the Next Record button

in the bottom section of the dialog box. To create a new mask, you can click the New (Blank) Record button

. After creating a new mask, you can click Close.
Once you have located the desired mask, you can click it and click Next to continue. The second page of the wizard allows you to accept or customize the mask you had selected. Once you are ready, you can click Next. The third page presents an option that allows you to specify how the value in the field would be stored in the database. It presents two radio buttons and you can either accept the suggestion or select the other and click Next. The fourth page of the wizard doesn't do much. It simply lets you know that the wizard is ready to create the mask. Therefore, you can click Finish.
If none of the masks provided by the wizard suits you, you can create your own. To do that, click the Input Mask property for the desired fields and uses the following characters to create the mask:
Character | Used to enter or accept |
0 | A single digit |
9 | A single digit or space |
# | A digit, space, + or - |
L | An alphabetical character |
? | A letter |
A | A letter or a digit |
a | A letter, a digit, or nothing |
& | A character or space |
C | A character, space, or nothing |
. | A decimal place holder; for US English, this would be the period |
, | Thousand separator; for US English, this would be a comma |
:;-/ | Date and time separator, as specified in the Regional Settings of Control Panel |
< | A letter; the letter will be converted to lowercase |
> | A letter; the letter will be converted to uppercase |
! | Anything; the mask is filled from right to left for this position |
| | Anything; the character that follows this one will be displayed itself. For example, if you type |L, the letter L would be displayed instead of being used a mask |
You can use any of these symbols to create a mask. If you want to include a word or sentence as part of the mask, type it in any section as desired. Here are examples of Custom Masks:
Mask | Example 1 | Example 2 | Example 3 |
LL | dh | fT | Gm |
>LL\-00 | WE-47 | | |
#0L | 8f | 16a | 04t |
>LL\-000 | WE-883 | | |
000\-000\-0000 | 265-387-6498 | | |
##\-## | 02-37 | -9-5+ | -6-35 |
&#\-L0\-## | 5-u5-00 | | |
\(000") "000\-0000 | (301) 294-6464 | | |
!\(999") "000\-0000"" | ( ) 392-3873 | | |
00\-00\-00\-00 | 28-73-68-46 | | |
>00\-LLLL\-0 | 78-DRUG-9 | | |
>L<LLL | Jean | | |
>L<????????????? | Helene | Antananarivo | |
Practical Learning: Using Input Masks |
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- In the top section, click State
- In the lower section, click Input Mask, type >LL and press Enter
- In the upper section, click ZIP Code
- In the lower section, click the Input Mask field and click its ellipsis button

- When asked whether you want to save the table, click Yes
- In the first page of the wizard, click ZIP Code
- Click the Try It text box:

- Click Next

- Click Next
- Click the first radio button

- Click Next
- Click Finish
- Save the table
- To switch its view, right-click the Properties tab and click Datasheet View
- Enter the following records:
Address | City | State | ZIP Code |
1640 Lombardo Ave | Silver Spring | MD | 20904-1136 |
10315 Hacht Rd | College Park | MD | 20747 |
6366 Lolita Drive | Laurel | MD | 20707-1014 |
9002 Palasko Hwy | Tysons Corner | VA | |
| | DC | 20011 |
| Alexandria | VA | 22024-2006 |
The & operator is used to add one string to another. It can also be used to append the contents of two controls or two expressions. This is considered as concatenating them. For example, it could allow you to concatenate a first name and a last name, producing a full name. The general syntax of the concatenation operator is:
Value1 & Value2
The values on both sides can be constant values. Here is an example:
"Eating" & " Food"
One value can be the name of a field and the other a constant value or both values can be the names of field. Just as you can involve two values in a concatenation, you can also use more than one. All of them be can constant strings. The operation can involve only the names of fields, or the expression can be a combination of constant values and names of fields.
To concatenate more than two strings, you can use as many & operators between any two expressions as necessary. After concatenating the strings or values, you can assign the result to another value or expression using the assignment operator. The formula to use is:
=Field1 & Field2 & Field_n
Here is an example:
= LastName & ", " & FirstName
Once again, you should include the name of a field in square brackets:
=[LastName] & ", " & [FirstName]
Here is another example:
=[Address] & " " & [City] & " " & [State] & " " & [ZIPCode] & " " & [Country]
This would display a complete address in a field.
Trimming is an operation that gets rid of leading or ending spaces in a string. To remove any (empty) space on the left side of a string, you can use the LTrim() function. Its syntax is:
LTrim(Expression As String) As String
The original string is passed as argument to the function. The function then removes any empty space from the left of the string and then the function returns the resulting string (without any space from the left section). If the original string does not have any leading space, the function would return the same string.
To remove any space on the right side of a string, you can use the RTrim() function. Its syntax is:
RTrim(Expression As String) As String
The string to trim is passed as argument to the function. If that string has space on its right, this function would remove it and return the same string without any trailing space. Otherwise, the original string would be returned.
To remove empty spaces on both the left and the right sides of a string, call the Trim() function. Its syntax is:
Trim(Expression As String) As String
The string is passed to the function. The function then removes empty spaces, if any on each side, and the function returns the new string.
Character Case Conversion |
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There are various techniques you can use to convert a string from lowercase to uppercase and vice-versa. An alphabetical character is recognized as being in lowercase if it is one of the following characters: a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z. On the other hand, a character qualifies as uppercase if it is one of A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z. All the other symbols are ignored even if on the keyboard you would press Shift to type them.
To convert a lowercase character or string to uppercase, you can use the UCase() function. Its syntax is:
UCase(Expression As String) As String
This function takes a string as argument and examines each one of its characters. If a character is an alphabetic character in lowercase, it would be converted to uppercase. If the character is either an alphabetical character in uppercase or it is not an alphabetic character, it would be kept "as is".
To convert a character or a string from uppercase to lowercase, you can call the LCase() function. Its syntax is:
LCase(Expression As String) As String
This function takes a string as argument and examines each one of its characters. If a character is an alphabetic character in uppercase, it would be converted to lowercase. The case of all the other characters would be ignored.
String comparison allows you to find out which one of two strings is longer or whether both strings are equal. When comparing two strings, the database engine checks lowercase and uppercase characters. To compare two strings, you can use the StrComp() function. Its syntax is:
StrComp(Expression1 As String, Expression2 As String, Option) As Number
The function takes two strings and an option as arguments. It then compares the strings:
- If the strings are the same, the function returns the number 0
- If the first string is shorter than the second, the function returns the number -1
- If the first string is longer than the second, the function returns 1
- If one of the strings is null, the function returns null
The third argument is optional, which means you don't have to provide it. If you want to influence the way the comparison is made, you can pass the third argument with one of the following values: -1, 0, 1, 0r 2.
There are many operations you can perform on individual characters of a string. These include creating a sub-string, checking for a character, finding the position of a character, or deleting a character or characters. These operations can be valuable when creating objects such as login dialog boxes.
To create a string that is made of one or more characters from the left side of a string, you can call the Left() function. Its syntax is:
Left(Expression As String, Length As Number) As String
This function takes two arguments. The first argument is a string. The second argument specifies the number of characters to be considered from the first argument. The function would then create a new string that is made of the number of characters from the left side of the first argument. To illustrate, consider a string such Republic passed as the first argument and consider that you pass 3 as the second argument:
Left("Republic", 3)
The function would consider the left 3 characters of the Republic argument and it would produce that sub-string. The resulting string would be Rep.
To create a string that is made of one or more characters from the right side of a string, you can call the Right() function. Its syntax is:
Right(Expression As String, Length As Number) As String
This function also takes a string and a number as arguments. The function then creates a new string that is made of the number of characters from the left side of the first argument. Consider the following example:
Right("Midnight", 5)
The function would consider the last 5 characters of the Midnight argument and it would produce that sub-string. The resulting string would be night.
To create a string that is made of one or more characters from anywhere in a string, you can call the Mid() function. Its syntax is:
Mid(Expression As String, start As Number, Optional Length) As String
This function also takes 3 arguments with required: a string, a starting position and an optional number. The function creates a new string using the first argument, from the start number. If you don't pass the third argument, the function returns a string from that position to the end of the string. Consider the following example:
Mid("Ideal", 2)
This function would start creating a new function from the second position of Ideal to the end. The resulting string would be "deal".
If you pass the third argument, the function would create a new string from the start position. Then it would count the Length number of characters from the start position and it would create that new string. Consider the following example:
Mid("Elizabeth", 2, 4)
This would produce "liza".
Locating a Character or a Sub String |
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You can analyze a string and find out whether it contains a certain character or a sub string. If it does, you can get the position of the character or the substring and use that information as you see fit. To support this operation, you can use the InStr() function. Its syntax is:
InStr(Optional start As Number,
string1 As String,
string2 As String) As Number
This function takes 3 arguments with 2 required. The second argument is the string to be examined. In it, the function would look for the character or string of the second argument. If you don't pass the first argument, the function would start from the beginning string of the second argument. If it finds it, it returns the position, a number from where the string2 string was found. If it doesn't find it, it returns 0.
Character or Sub-String Replacement |
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When performing some operations on strings, you may want to find out whether a certain character or group of characters has been provided in a string. If so, you may want to replace it with a different character or with a new sub string. To perform this operation, you can call the Replace() function. Its syntax is:
Replace(Expression As String,
LookFor As String,
ReplaceWith As String,
start As Number,
count As Number,
Option)
The Replace() function will look for the LookFor character or sub-string in the Expression string. If it finds it, then it will replace the LookFor character or sub string with the ReplaceWith character or sub-string. These first three arguments are required. Here is an example:
Replace("Elisabeth", "s", "z")
In this case, the function would look for s in Elisabeth. If it finds it, then it replaces it with z. If its doesn't find, it would not do anything.
By default, or in the absence of the other arguments, the Replace() function examines the Expression argument from start to end. If you don't want to consider all characters, you can pass the 4th argument to specify from what position of the Expression to work on. Then, the function would consider characters from that position to the end. If you want, you can ask the function to consider only a certain number of characters. To do this, pass a 5th argument as a number.
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