C#: Is it possible to store a Decimal Array in an SQL database?

I need the entire array to be imported into the database as one single value though because the lab project has several specimens each with their own set of 250 or so Decimal points (which will be stored as arrays, too)

So you're trying to pound a nail, should you use an old shoe or a glass bottle?

The answer here isn't "serialize the array into XML and store it in a record". You really want to strive for correct database design, and in your case the simplest design is:

Specimens
---------
specimenID (pk int not null)

SpecimenData
------------
dataID (pk int not null
specimenID (fk int not null, points to Specimens table)
awesomeValue (decimal not null)

Querying for data is very straightforward:

SELECT * FROM SpecimenData where specimenID = @specimenID

As long as you don't to access the the individual values in your queries, you can serialize the array and store it as a blob in the database.

Presumably you could serialize the decimal array in C# to a byte array, and save that in a binary field on a table. Your table would have two fields: SpecimenID, DecimalArrayBytes

Alternately you could have a many to many type table and not store the array in one piece, having fields: SpecimenID, DecimalValue, and use SQL like

SELECT DecimalValue FROM Table WHERE SpecimenID = X

You can serialize the array and store it as a single chunk of xml/binary/json. Here is an example of serializing it as xml.

public static string Serialize<T>(T obj)
{
    StringBuilder sb = new StringBuilder();
    DataContractSerializer ser = new DataContractSerializer(typeof(T));
    ser.WriteObject(XmlWriter.Create(sb), obj);
    return sb.ToString();
}

You want two tables. One to store an index, the other to store the decimal values. Something like this:

create table arrayKey (
   arrayId int identity(1,1) not null
)

create table arrayValue (
   arrayID int not null,
   sequence int identity(1,1) not null,
   storedDecimal decimal(12,2) not null
)

Insert into arrayKey to get an ID to use. All of the decimal values would get stored into arrayValue using the ID and the decimal value to store. Insert them one at a time.

When you retrieve them, you can group them by arrayID so that they all come out together. If you need to retrieve them in the same order you stored them, sort by sequence.

Although any given example might be impractical, via programming you can engineer any shape of peg into any shape of hole.

You could serialize your data for storage in a varbinary, XML-ize it for storage into a SQL Server XML type, etc.

Pick a route to analyze and carefully consider. You can create custom CLR libraries for SQL as well so the virtual sky is the limit.