如何以编程方式复制具有复合键的MS Access表模式

假设源MS Access数据库有一个名为MyTable1的表。假设MyTable1有一个复合主键（两个独立字段Phone和City的组合）。现在，当我使用以下代码进行复制时，它不会将City作为目标表中复合键的一部分。如何修复

            ADOX.Table sourceTable = default(ADOX.Table);
            sourceTable = sourceCat.Tables[tableName.Trim()];
            ADOX.Table newTable = new ADOX.Table();
            newTable.ParentCatalog = targetCat;
            tempNewtableName = sourceCat.Tables[tableName.Trim()].Name;
            newTable.Name = tempNewtableName;
            ADOX.Column newCol = default(ADOX.Column);
            DataTable primaryKeyDT = new DataTable();
            primaryKeyDT.Columns.Add("FieldName");
            primaryKeyDT.Columns.Add("Type");
            foreach (ADOX.Index idx1 in sourceCat.Tables[tableName].Indexes)
            {
                if (idx1.PrimaryKey == true)
                {
                    primaryKeyDT.Rows.Add(idx1.Columns[0].Name, idx1.Name);
                }
            }

            foreach (ADOX.Column SourceCol in sourceTable.Columns)
            {
                newCol = new ADOX.Column();
                newCol.Type = SourceCol.Type;
                newCol.DefinedSize = SourceCol.DefinedSize;
                newCol.ParentCatalog = targetCat;
                newCol.Precision = SourceCol.Precision;
                newCol.DefinedSize = SourceCol.DefinedSize;
                newCol.Attributes = SourceCol.Attributes;
                newCol.Name = SourceCol.Name;
                newCol.NumericScale = SourceCol.NumericScale;
                newTable.Columns.Append(newCol);
                DataRow[] results = primaryKeyDT.Select("FieldName ='" + SourceCol.Name + "'");
                if (results.Length > 0)
                {
                    idx = new Index();
                    idx.Name = "idx_" + SourceCol.Name;
                    idx.PrimaryKey = true;
                    idx.Columns.Append(SourceCol.Name);
                    newTable.Indexes.Append(idx);
                }
            }
            targetCat.Tables.Append(newTable);