memo field

[inungh]

I need have memo filed for my table.
I would like to know what are the difference between memo and text
field.
I know that text filed has maximum 255 characters and fixed length.
What is field length for memo field? How do I calcualte the how much
space used for memo field. When is the best choice for memo field.
Because my data length vary, is it best to use memo? or it is better
to use text field if the length is less than 255 characters?


Your information is great appreciated,

 

[scubadiver]

I think the number of characters for a memo field runs into thousands.

If you want to calculate how many characters have been used in a memo field
you can use a text box with a calculation that updates after everytim the
memo field has been updated with text.

 

[Jerry Whittle]

A memo field in Access 2003 or older can easily handle 64,000 characters.
That's about a chapter of a book. There's even ways through code to stuff
even more than that into a memo field.

But memo fields aren't "free". There are some things that you can't do with
a memo field like certain searches, sorting, and updates. Also memo fields
are known to cause corruption problems and can be difficult to export to
other file formats.

If the data in the field is always going to be under 255 characters, use a
text field. Text fields are much more stable and useful. If the field will
need to contain more than that, then consider using a Memo field.

 

[John W. Vinson]

I need have memo filed for my table.
I would like to know what are the difference between memo and text
field.
I know that text filed has maximum 255 characters and fixed length.

"It ain't what you don't know that's a problem, it's what you know for certain
that ain't so!"

Text fields are limited to 255 bytes but they are NOT fixed length - the SQL
equivalent datatype is Varchar. A Text field will actually store only those
characters which are entered; if you type 4 letters into it, that's all that
will be written to disk.

What is field length for memo field?

Up to two billion bytes (65536 bytes if you enter it using a form or
datasheet).

How do I calcualte the how much
space used for memo field.

The number of characters entered plus 16 or 24 bytes of overhead, depending on
version. The overhead applies even if there is nothing in the field.

When is the best choice for memo field.
Because my data length vary, is it best to use memo? or it is better
to use text field if the length is less than 255 characters?

Since text is also variable length, AND lets you index the field, include it
in keys, sort by it - while Memos don't - use a Text in preference.

 

[David W. Fenton]

Up to two billion bytes (65536 bytes if you enter it using a form
or datasheet).

Er, what? In which version of Access are memo fields 2 billion
bytes? Are you referring to BLOBs or OLE or the new attachment
fields in A2K7?

 

[John W. Vinson]

Er, what? In which version of Access are memo fields 2 billion
bytes? Are you referring to BLOBs or OLE or the new attachment
fields in A2K7?

Sorry! 1 GByte, not 2.. From the Help for "Specifications":

Number of characters in a Memo field: 65,535 when entering data through the
user interface; 1 gigabyte of character storage when entering data
programmatically

 

[David W. Fenton]

Sorry! 1 GByte, not 2.. From the Help for "Specifications":

Number of characters in a Memo field: 65,535 when entering data
through the user interface; 1 gigabyte of character storage when
entering data programmatically

Which versions of Jet would that apply to?

 

[John W. Vinson]

Which versions of Jet would that apply to?

A2000 through A2003 I'm sure - not certain about other versions.