基於ArcGIS10.0和Oracle10g的空間數據管理平臺十四（C#開發）-元數據庫庫管理

由於前段時間工作很忙而且出差去了北京一個多月，所以很久沒有介紹了關於基於ArcGIS10.0和Oracle10g的空間數據管理平臺這個項目的相關功能實現了，今天開始介紹一個新的功能實現，就是元數據庫的管理。

    所謂元數據就是描述數據的數據，元數據庫就是存放描述數據的數據。元數據主要用於描述數據的特徵等的數據，在很多場合下都會遇到元數據，例如文件系統裏面有。這裏介紹的元數據主要是指描述空間數據特徵的元數據，例如屬於哪一類數據等。

    今天由於時間關係就簡單介紹一下元數據庫管理的實現。

1.初始化顯示元數據庫信息的頭部信息

 

/// <summary>
/// 初始化datagridView的頭部顯示信息
/// </summary>
private void InitDataGridView()
{
    //dataGridViewX1.Rows.Clear();
    SqlHelper sh = new SqlHelper();
    string sql = "select id,name,description from jcsjk_databaseinfo";
    DataSet ds = sh.ReturnDataSet(sql, "jcsjk_databaseinfo");
    dataGridViewX1.DataSource = ds.Tables[0];

    dataGridViewX1.Columns[0].HeaderText = "元數據庫ID";
    dataGridViewX1.Columns[0].Width = 200;
    dataGridViewX1.Columns[1].HeaderText = "元數據庫名稱";
    dataGridViewX1.Columns[1].Width = 200;

    dataGridViewX1.Columns[2].HeaderText = "元數據庫描述信息";
    dataGridViewX1.Columns[2].Width = 200;

}

2.刪除元數據庫

/// <summary>
 /// 刪除元數據庫
 /// </summary>
 /// <param name="sender"></param>
 /// <param name="e"></param>
 private void delMetaDatabaseBtn_Click(object sender, EventArgs e)
 {
     //1.刪除所有表
     if (dataGridViewX1.CurrentRow.Index < 0)
     {
         MessageBox.Show("請選擇需要刪除的數據庫那一行");
         return;
     }
     string strDatabaseName = dataGridViewX1.Rows[dataGridViewX1.CurrentRow.Index].Cells[1].Value.ToString();
     SqlHelper sh = new SqlHelper();
     string sql = "select table_name from user_tables where table_name like '" +
         strDatabaseName.ToUpper() + "/_%' ESCAPE '/'";
     OracleDataReader odr = sh.ReturnDataReader(sql);

     while (odr.Read())
     {
         //刪除關聯外鍵
         string strTemp = odr[0].ToString().ToUpper();
         strTemp = strTemp.Substring(strDatabaseName.Length + 1);
         sql = "select table_name,constraint_name from user_constraints where constraint_type='R'"
             + " and constraint_name like '" + strTemp + "%'";
         OracleDataReader odr1 = sh.ReturnDataReader(sql);

         while (odr1.Read())
         {
             sql = "ALTER TABLE " + odr1[0].ToString().ToUpper() + " DROP CONSTRAINT "
                 + odr1[1].ToString().ToUpper();
             sh.ExecuteSQL(sql);
         }
         sql = "drop table " + odr[0].ToString().ToUpper();
         sh.ExecuteSQL(sql);
     }
     //2.刪除記錄
     Hashtable ht = new Hashtable();
     ht.Add("name", strDatabaseName);
     try
     {
         sh.Del("jcsjk_databaseinfo", "name='" + strDatabaseName + "'", ht);
     }
     catch (Exception)
     {
         LogHelp.writeLog(FrmMain.metaUsername, "元數據庫管理",
         "刪除元數據庫<" + strDatabaseName + ">失敗!");
         MessageBox.Show("刪除元數據庫<" + strDatabaseName + ">失敗!");
     }

     LogHelp.writeLog(FrmMain.metaUsername, "元數據庫管理",
         "刪除元數據庫<" + strDatabaseName + ">成功!");
     MessageBox.Show("刪除元數據庫<" + strDatabaseName + ">成功!");
 }

 

3.清空元數據庫

/// <summary>
 /// 清空元數據庫中的數據
 /// </summary>
 /// <param name="sender"></param>
 /// <param name="e"></param>
 private void clearMetaDataBtn_Click(object sender, EventArgs e)
 {
     if (dataGridViewX1.CurrentRow.Index < 0)
     {
         MessageBox.Show("選擇數據庫！");
         return;
     }
     SqlHelper sh = new SqlHelper();
     string strDatabaseName = dataGridViewX1.CurrentRow.Cells[1].Value.ToString();
     //NewDataSet nds = new NewDataSet();
     string sql = string.Empty;
     sql = "select table_name from user_tables where table_name like '" +
         strDatabaseName.ToUpper() + "/_%' ESCAPE '/'";
     OracleDataReader odr = sh.ReturnDataReader(sql);

     while (odr.Read())
     {
         sql = "delete from " + odr[0].ToString().ToUpper();
         try
         {
             sh.ExecuteSQL(sql);
         }
         catch (Exception)
         {
             LogHelp.writeLog(FrmMain.metaUsername, "元數據庫管理",
                     "清空元數據庫<" + strDatabaseName + ">的數據失敗!");
             MessageBox.Show("清空元數據庫<" + strDatabaseName + ">的數據失敗!");
             return;
         }
     }
     LogHelp.writeLog(FrmMain.metaUsername, "元數據庫管理",
        "清空元數據庫<" + strDatabaseName + ">的數據成功!");
     MessageBox.Show("清空元數據庫<" + strDatabaseName + ">的數據成功!");
     /*
     foreach (DataTable dt in nds.Tables)
     {
             string strTableName = strDatabaseName + "_" + dt.TableName;
             sql = "select * from " + strTableName;
             DataSet ds = new DataSet();

             OracleDataAdapter oda = new OracleDataAdapter(sql,
                 ConfigurationSettings.AppSettings["ConnectionString"]);
             try
             {
                 oda.Fill(ds);
                 oda.Update(dt);
             }
             catch (Exception ex)
             {
                 LogHelp.writeLog(FrmMain.metaUsername, "元數據庫管理",
                     "清空元數據庫<" + strDatabaseName + ">的數據失敗!");
                 MessageBox.Show("清空元數據庫<" + strDatabaseName + ">的數據失敗!");
             }
     }
     LogHelp.writeLog(FrmMain.metaUsername, "元數據庫管理",
        "清空元數據庫<" + strDatabaseName + ">的數據成功!");
     MessageBox.Show("清空元數據庫<" + strDatabaseName + ">的數據成功!");
      * */
 }

    清空元數據庫與刪除元數據庫是不同的功能，刪除元數據庫就是把存放元數據的庫都一起刪除了，但是清空元數據庫只是把庫裏面的內容刪除，庫本身存在。

4.創建元數據庫

    這是比較複雜的一個功能，因爲創建一個元數據庫需要根據一定的標準來創建，這些標準都是通過xsd文件描述的，所以首先要解析這個xml的模式描述文件，然後根據解析的內容存放到相應的字段中去，具體實現如下：

private void createBtn_Click(object sender, EventArgs e)
{
    SqlHelper sh = new SqlHelper();
    string sql = string.Empty;

    if (databaseIDTxt.Text.Trim() == "" || databaseNameTxt.Text.Trim() == "")
    {
        errTxt.Text = "數據庫ID或名稱不能爲空.";
        return;
    }

    //查看元數據庫是否存在
    sql = "select * from jcsjk_databaseinfo where name='" + databaseNameTxt.Text + "'";

    if (sh.GetRecordCount(sql) > 0)
    {
        MessageBox.Show("此元數據庫已經存在,請從新命名元數據庫!");
        return;
    }

    Hashtable ht = new Hashtable();
    string strContent = string.Empty;
    DataSet ds = new DataSet();
    //從文件標準創建
    if (!checkBoxX1.Checked)
    {
        if (metaFileTxt.Text == "" || Path.GetExtension(metaFileTxt.Text).ToLower() != ".xsd")
        {
            errTxt.Text = "請選擇正確的XSD文件.";
            return;
        }
        if (metaIDTxt.Text.Trim() == "")
        {
            errTxt.Text = "元數據標準ID不能爲空.";
            return;
        }

        //1.讀入xsd文件
        ds.ReadXmlSchema(metaFileTxt.Text);

        //2.create table in tablespace
        try
        {
            OracleDataSchemaAdapter odsa = new OracleDataSchemaAdapter();
            odsa.Create(ds, true, databaseNameTxt.Text + "_", "SDE");
        }
        catch (ArgumentException ae)
        {
            LogHelp.writeLog(FrmMain.metaUsername, "元數據庫管理",
                    "創建元數據庫<" + databaseNameTxt.Text + ">失敗!");
            MessageBox.Show("-- Error --" + ae.Message + "-- Instructions --");
        }
        catch (FileNotFoundException)
        {
            LogHelp.writeLog(FrmMain.metaUsername, "元數據庫管理",
                    "創建元數據庫<" + databaseNameTxt.Text + ">失敗!");
            MessageBox.Show("File not found: " + metaFileTxt.Text);
        }
        catch (Exception)
        {
            LogHelp.writeLog(FrmMain.metaUsername, "元數據庫管理",
                    "創建元數據庫<" + databaseNameTxt.Text + ">失敗!");
            MessageBox.Show("創建元數據庫<" + databaseNameTxt.Text + ">失敗!");
        }

        //寫入元數據標準到數據庫
        StreamReader sr = new StreamReader(new FileStream(metaFileTxt.Text, FileMode.Open),
            System.Text.Encoding.GetEncoding("GB2312"));

        while (!sr.EndOfStream)
        {
            strContent += sr.ReadLine();
        }
        sr.Close();
        string strName = Path.GetFileNameWithoutExtension(metaFileTxt.Text);
        //
        sql = "select * from jcsjk_databaseinfo where name='" + strName + "'";
        if (sh.GetRecordCount(sql) <= 0)
        {
            XmlDocument xmlDoc = new XmlDocument();
            xmlDoc.Load(metaFileTxt.Text);
            XmlNodeList xnl = xmlDoc.GetElementsByTagName("xs:schema");
            XmlNode xn = xnl[0];
            //插入元數據標準到數據庫中，用參數才能插入，因爲content字段內容太大
            sql = "insert into jcsjk_metastand (id, name, content, org, version) values("
                + ":id,:name,:content,:org,:version)";
            OracleParameter[] op = new OracleParameter[5];
            op[0] = new OracleParameter();
            op[0].ParameterName = "id";
            op[0].OracleType = OracleType.NVarChar;
            op[0].Value = metaIDTxt.Text;
            op[1] = new OracleParameter();
            op[1].ParameterName = "name";
            op[1].OracleType = OracleType.NVarChar;

            string strValue = xn.ChildNodes[0].ChildNodes[1].InnerText;

            strValue = strValue.Substring(strValue.IndexOf('：') + 1);
            op[1].Value = strValue;
            op[2] = new OracleParameter();
            op[2].ParameterName = "content";
            op[2].OracleType = OracleType.Clob;
            op[2].Value = strContent;
            strValue = xn.ChildNodes[0].ChildNodes[2].InnerText;
            strValue = strValue.Substring(strValue.IndexOf('：') + 1);
            op[3] = new OracleParameter();
            op[3].ParameterName = "org";
            op[3].OracleType = OracleType.NVarChar;
            op[3].Value = strValue;
            strValue = xn.ChildNodes[0].ChildNodes[0].InnerText;
            strValue = strValue.Substring(strValue.IndexOf('：') + 1);
            op[4] = new OracleParameter();
            op[4].ParameterName = "version";
            op[4].OracleType = OracleType.NVarChar;
            op[4].Value = strValue;
            try
            {
                sh.ExecuteNonQuery(sql, op);
            }
            catch (Exception ex)
            {
                LogHelp.writeLog(FrmMain.metaUsername, "元數據庫管理",
                    "寫入元數據標準<" + strName + ">到數據庫失敗!");
                MessageBox.Show("寫入元數據標準<<" + strName + ">到數據庫失敗!");
            }
        }
    }
    //從數據庫以存儲的標準創建
    else
    {
        string strStandName = comboBoxEx1.SelectedItem.ToString();

        sql = "select content from jcsjk_metastand where name='" + strStandName + "'";
        OracleDataReader odr = sh.ReturnDataReader(sql);
        if (odr.Read())
        {
            StreamWriter bw = new StreamWriter(new FileStream("temp.xsd", FileMode.Create),
                System.Text.Encoding.GetEncoding("GB2312"));

            bw.Write(odr[0].ToString());

            bw.Close();
            ds.ReadXmlSchema("temp.xsd");
            System.IO.File.Delete("temp.xsd");
            try
            {
                OracleDataSchemaAdapter odsa = new OracleDataSchemaAdapter();
                odsa.Create(ds, true, databaseNameTxt.Text + "_", "SDE");
            }
            catch (ArgumentException ae)
            {
                LogHelp.writeLog(FrmMain.metaUsername, "元數據庫管理",
                        "創建元數據庫<" + databaseNameTxt.Text + ">失敗!");
                MessageBox.Show("-- Error --" + ae.Message + "-- Instructions --");
            }
            catch (FileNotFoundException)
            {
                LogHelp.writeLog(FrmMain.metaUsername, "元數據庫管理",
                        "創建元數據庫<" + databaseNameTxt.Text + ">失敗!");
                MessageBox.Show("File not found: " + metaFileTxt.Text);
            }
            catch (Exception)
            {
                LogHelp.writeLog(FrmMain.metaUsername, "元數據庫管理",
                        "創建元數據庫<" + databaseNameTxt.Text + ">失敗!");
                MessageBox.Show("創建元數據庫<" + databaseNameTxt.Text + ">失敗!");
            }
        }

    }

    //插入元數據庫信息到數據庫
    sql = "select * from jcsjk_databaseinfo where name='" + databaseNameTxt.Text + "'";
    if (sh.GetRecordCount(sql) <= 0)
    {
        ht.Clear();
        ht.Add("ID", databaseIDTxt.Text);
        ht.Add("NAME", databaseNameTxt.Text);
        if (descriptionText.Text != "")
        {
            ht.Add("DESCRIPTION", descriptionText.Text);
        }
        try
        {
            sh.Insert("jcsjk_databaseinfo", ht);
        }
        catch (Exception)
        {
            LogHelp.writeLog(FrmMain.metaUsername, "元數據庫管理",
                "插入元數據庫<" + databaseNameTxt.Text + ">信息到數據庫失敗!");
            MessageBox.Show("插入元數據庫<<" + databaseNameTxt.Text + ">信息到數據庫失敗!");
        }
    }

    LogHelp.writeLog(FrmMain.metaUsername, "元數據庫管理",
               "創建元數據庫<" + databaseNameTxt.Text + ">成功!");
    MessageBox.Show("創建元數據庫<" + databaseNameTxt.Text + ">成功!");
    Close();
}

    到此元數據庫的管理基本內容已經介紹完畢。