Retrieve varbinary(MAX) from SQL Server to byte[] in C#

Question

I'm trying to get a varbinary(MAX) from SQL Server to a byte[] variable in C#.

How can I do this?

Thanks

score 28 · Accepted Answer · answered Oct 11 '11 at 10:29

28

private static byte[] getDocument(int documentId)
{
    using (SqlConnection cn = new SqlConnection("..."))
    using (SqlCommand cm = cn.CreateCommand())
    {
        cm.CommandText = @"
            SELECT DocumentData
            FROM   Document
            WHERE  DocumentId = @Id";
        cm.Parameters.AddWithValue("@Id", documentId);
        cn.Open();
        return cm.ExecuteScalar() as byte[];
    }
}

answered Oct 11 '11 at 10:29

Rubens Farias

57,174
8
131
162

1

Execute scalar returns a max of 2033 characters (https://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlcommand.executescalar%28v=vs.110%29.aspx). So this wouldn't work if your data was longer than 2033 bytes right? – Ian May 09 '17 at 20:25

score 1 · Answer 2 · answered Feb 15 '18 at 07:52

1

You have to SELECT DATALENGTH(data) and data

where data is your varbinary(max)

int i=0;
long dataLen = dr.GetInt64(i++);
if (dataLen > 0)
{
    Data = new byte[dataLen];
    dr.GetBytes(i++, 0, Data, 0, (int)dataLen);
}

answered Feb 15 '18 at 07:52

DiSaSteR

608
6
11

Retrieve varbinary(MAX) from SQL Server to byte[] in C#

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