variable length field in Database

Question

Is there any way to store variable length list into database in SQL or any other database engine ??

Here list means no. of elements in the array. For e.g. an array of numbers.

But in my actual application things to be stored are objects and hence cannot be stored simply as comma separated list.

What do you mean by "list"? An example would help, along with what database you plan to do this in — OMG Ponies, Dec 22 '10 at 07:03
if you mean a comma seperated list, yes, you can; BUT don't! — Mitch Wheat, Dec 22 '10 at 07:04

score 2 · Answer 1 · answered Dec 22 '10 at 07:06

One Table:

Id (PK), ListItem varchar(255), ListId (int) - ListId is unique to each list and you use that to grab all items on the list, you could add additional columns for ordering if you wanted.

Two Tables

List (Table) -ListId (pk) -ListTitle varchar(255)

Item (Table) -ItemId (pk) -ListId (fk -> List.ListId) -ItemName varchar(255) -Order (int) - for ordering

score 2 · Accepted Answer · answered Dec 23 '10 at 01:37

Some SQL databases support the ARRAY type as the type of a column. An ARRAY is variable length and can hold objects of the same type. See details below which apply to databases that support the SQL Standard:

http://hsqldb.org/doc/2.0/guide/sqlgeneral-chapt.html#N106FE

score 0 · Answer 3 · answered Dec 22 '10 at 07:04

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How about 2 tables, with linked 1 to many references?

Or if you are refering to a single column in a ro, use seperated (comma) strings?

answered Dec 22 '10 at 07:04

Adriaan Stander

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score 0 · Answer 4 · answered Dec 22 '10 at 07:05

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You can make the use of length function for calculating the length of the variable and the while inserting that variable Insert the length along with it... Thats it.

hAPPY cODING...

answered Dec 22 '10 at 07:05

Suresh Varma

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variable length field in Database

4 Answers4