从SQL Server中检索varbinary（MAX）到C＃中的byte []

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

我正在尝试从SQL Server获取varbinary（MAX）到C＃中的byte []变量。

How can I do this?

我怎样才能做到这一点？

Thanks

谢谢

2 个解决方案

#1

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[];
    }
}

#2

You have to SELECT DATALENGTH(data) and data

您必须SELECT DATALENGTH（数据）和数据

where data is your varbinary(max)

数据是你的varbinary（最大）

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

#1

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[];
    }
}

#2