挣扎于SQL BCP（uniqidentifier，列的默认值……）

VARCHAR(1000)

private static string  CreateFormatFile(string filePath, SqlConnection connection, string tableName, string[] sourceFields, string[] destFields, string fieldDelimiter, string fieldQuote)
    {
    string         formatFilePath = filePath + \".fmt\";
    StreamWriter   formatFile     = null;
    SqlDataReader  data           = null;
    try
        {
        // Load the metadata for the destination table, so we can look up fields\' ordinal positions
        SqlCommand  command = new SqlCommand(\"SELECT TOP 0 * FROM \" + tableName, connection);
                    data    = command.ExecuteReader(CommandBehavior.SchemaOnly);
        DataTable   schema  = data.GetSchemaTable();

        Dictionary<string, Tuple<int, int>>  metadataByField = new Dictionary<string, Tuple<int, int>>();
        foreach (DataRow row in schema.Rows)
            {
            string  fieldName = (string)row[\"ColumnName\"];
            int     ordinal   = (int)row[\"ColumnOrdinal\"] + 1;
            int     maxLength = (int)row[\"ColumnSize\"];
            metadataByField.Add(fieldName, new Tuple<int, int>(ordinal, maxLength));
            }

        // Begin the file, including its header rows
        formatFile = File.CreateText(formatFilePath);
        formatFile.WriteLine(\"10.0\");
        formatFile.WriteLine(sourceFields.Length);

        // Certain strings need to be escaped to use them in a format file
        string  fieldQuoteEscaped     = fieldQuote     == \"\\\"\" ? \"\\\\\\\"\" : fieldQuote;
        string  fieldDelimiterEscaped = fieldDelimiter == \"\\t\" ? \"\\\\t\"  : fieldDelimiter;

        // Write a row for each source field, defining its metadata and destination field
        for (int i = 1;  i <= sourceFields.Length;  i++)
            {
            // Each line contains (separated by tabs): the line number, the source type, the prefix length, the field length, the delimiter, the destination field number, the destination field name, and the collation set
            string  prefixLen   = i != 1 || fieldQuote == null ? \"0\" : fieldQuote.Length.ToString();
            string  fieldLen;
            string  delimiter   = i < sourceFields.Length ? fieldQuoteEscaped + fieldDelimiterEscaped + fieldQuoteEscaped : fieldQuoteEscaped + @\"\\r\\n\";
            string  destOrdinal;
            string  destField   = destFields[i - 1];
            string  collation;
            if (destField == null)
                {
                // If a field is not being imported, use ordinal position zero and a placeholder name
                destOrdinal = \"0\";
                fieldLen    = \"32000\";
                destField   = \"DUMMY\";
                collation   = \"\\\"\\\"\";
                }
            else
                {
                Tuple<int, int>  metadata;
                if (metadataByField.TryGetValue(destField, out metadata) == false)  throw new ApplicationException(\"Could not find field \\\"\" + destField + \"\\\" in table \\\"\" + tableName + \"\\\".\");
                destOrdinal = metadata.Item1.ToString();
                fieldLen    = metadata.Item2.ToString();
                collation   = \"SQL_Latin1_General_CP1_CI_AS\";
                }
            string  line = String.Join(\"\\t\", i, \"SQLCHAR\", prefixLen, fieldLen, \'\"\' + delimiter + \'\"\', destOrdinal, destField, collation);
            formatFile.WriteLine(line);
            }

        return formatFilePath;
        }
    finally
        {
        if (data       != null)  data.Close();
        if (formatFile != null)  formatFile.Close();
        }
    }