使用ADOX创建Access db

Question

我正在尝试创建一个由两个表组成的Access数据库。我在下面的方法中获得了第88行的System.Runtime.InteropServices.COMException。当我试图将表附加到Catalog对象时，会出现异常。谁能解释一下是怎么回事，以及如何解决这个问题？

public bool CreateNewAccessDatabase(string fileName)
    {
        bool result = false;

        ADOX.Catalog cat = new ADOX.Catalog();
        ADOX.Table provTable = new ADOX.Table();
        ADOX.Key provKey = new ADOX.Key();
        ADOX.Table locTable = new ADOX.Table();
        ADOX.Key locKey = new ADOX.Key();
        ADOX.Column provCol = new Column();
        ADOX.Column locCol = new Column();


        //Create the Province table and it's fields. 
        provTable.Name = "Provinces";
        provCol.Name = "id";
        provCol.Type = ADOX.DataTypeEnum.adInteger;
        provTable.Columns.Append(provCol);            
        provTable.Columns.Append("name", ADOX.DataTypeEnum.adVarWChar, 4);

        provKey.Name = "Primary Key";
        provKey.Columns.Append("id");
        provKey.Type = KeyTypeEnum.adKeyPrimary;

        //Create the Locations table and it's fields
        locTable.Name = "Locations";
        locCol.Name = "id";
        locCol.Type = ADOX.DataTypeEnum.adInteger;
        locTable.Columns.Append(locCol);
        locTable.Columns.Append("name", ADOX.DataTypeEnum.adVarWChar, 50);
        locTable.Columns.Append("price", ADOX.DataTypeEnum.adVarWChar, 8);

        locKey.Name = "Primary Key";
        locKey.Columns.Append("id");
        locKey.Type = KeyTypeEnum.adKeyPrimary;

        try
        {
            cat.Create("Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + fileName + "; Jet OLEDB:Engine Type=5");

            // Must create database file before applying autonumber to column
            provCol.ParentCatalog = cat;
            provCol.Properties["AutoIncrement"].Value = true;

            locCol.ParentCatalog = cat;
            locCol.Properties["AutoIncrement"].Value = true;

            cat.Tables.Append(provTable);  // <<< Exception triggered here
            cat.Tables.Append(locTable);

            //Now Close the database
            ADODB.Connection con = cat.ActiveConnection as ADODB.Connection;
            if (con != null)
                con.Close();

            result = true;
        }
        catch (Exception ex)
        {
            Debug.WriteLine(ex.StackTrace);
            result = false;
        }
        cat = null;
        return result;
    }

Answer 1

您将文本字段声明为ADOX.DataTypeEnum.adVarChar，但所有Access Text字段都能够存储Unicode，因此需要将它们声明为ADOX.DataTypeEnum.adVarWChar。