這幾天學習數據庫操作,就自己封裝了一個數據庫操作類,下面是代碼展示
下面的例子是Access數據庫
也可能用在Sql數據庫中,只在在第一行代碼上修改標識符即可
#define OLEDB_
using System;
using System.Data;
using System.Data.OleDb;
using System.Drawing;
using System.IO;
using System.Windows.Forms;
namespace MYDATACLASS
{
#if OLEDB_
using MyCommand = OleDbCommand;
using MyConnection = OleDbConnection;
using MyDataAdapter = OleDbDataAdapter;
using MyDataRead = OleDbDataReader;
using MyParameter = OleDbParameter;
#elif SQL_
using MyCommand = SqlCommand;
using MyConnection = SqlConnection;
using MyDataAdapter = SqlDataAdapter;
using MyCommandBuilder = SqlCommandBuilder;
using MyParameter = SqlParameter;
using MyDataRead = SqlDataReader;
//....
#endif
/// <summary>
/// 封裝對數庫操作的靜態方法類
/// <para>GetTable 獲得要查詢的DataTable表</para>
/// <para>GetDataSet 獲得查詢的DataSet表的集合</para>
/// <para>GetDataRead 獲得查詢的DataRead對象</para>
/// <para>ExecuteNonQuery 執行數據的增,刪,改等操作</para>
/// <para>ImageToByte,BetyToImage,字節byte[]和Image相互轉換</para>
/// <para>版權:greenleaf1976</para>
/// <para>創建時間:2021-07-16</para>
/// </summary>
public class BaseADO
{
public static MyConnection conn = null;
public static string Conn_String= @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=D:\MyAccessFile\newToxinlu.accdb";
public BaseADO() { }
~BaseADO()
{
conn.Dispose();
//CloseConn();
}
/// <summary>
/// 初始化Conn對象,並打開連接
/// </summary>
private static void InitConnection()
{
if (conn == null)
conn = new MyConnection(Conn_String);
if (conn.State == ConnectionState.Closed)
conn.Open();
if(conn.State==ConnectionState.Broken)
{
conn.Close();
conn.Open();
}
}
/// <summary>
/// 獲得查詢結果的表,如果只想用Sql語句,后面參數可省略
/// <para>如果用Sql+參數列表查詢,格式為:</para>
/// <para>(sql,mPars:pars)格式跳過中間的參數,也就是給指定的參數賦值</para>
/// </summary>
/// <param name="sqlStr">Sql語句或是儲存過程名</param>
/// <param name="cmdType">選擇用Sql語句還是儲存過程查詢</param>
/// <param name="mPars">參數列表</param>
/// <returns></returns>
public static DataTable GetDataTable(string sqlStr, CommandType cmdType = CommandType.Text, params MyParameter[] mPars)
{
InitConnection();
DataTable dt = new DataTable();
MyCommand cmd = null;
MyDataAdapter da = null;
try
{
cmd = new MyCommand(sqlStr, conn);
cmd.CommandType = cmdType;
if(mPars.Length!=0)
{
cmd.Parameters.Clear();
cmd.Parameters.AddRange(mPars);
}
da = new MyDataAdapter(cmd);
da.Fill(dt);
}
catch (System.Exception ex)
{
MessageBox.Show(ex.Message);
}
finally
{
da.Dispose();
cmd.Dispose();
conn.Close();
}
return dt;
}
/// <summary>
/// 獲得Sql語句或是儲存過程查詢的表的集合
/// </summary>
/// <param name="sqlStr">Sql語句或是儲存過程名</param>
/// <param name="cmdType">是用Sql語句還是儲存過程查詢</param>
/// <param name="mPars">參數列表</param>
/// <returns>查詢表的集合DataSet</returns>
public static DataSet GetDataSet(string sqlStr, CommandType cmdType = CommandType.Text, params MyParameter[] mPars)
{
InitConnection();
DataSet ds = new DataSet();
MyDataAdapter da = null;
MyCommand cmd = null;
try
{
cmd = new MyCommand();
cmd.CommandText = sqlStr;
cmd.Connection = conn;
cmd.CommandType = cmdType;
if(mPars.Length!=0)
{
cmd.Parameters.Clear();
cmd.Parameters.AddRange(mPars);
}
da = new MyDataAdapter(cmd);
da.Fill(ds);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
finally
{
cmd.Dispose();
da.Dispose();
conn.Close();
}
return ds;
}
/// <summary>
/// 通過Sql語句查詢,返回DataRead對象
/// <para>不能斷開連接,查詢后手動關閉連接</para>
/// <para>多用於遞歸加載數據用</para>
/// </summary>
/// <param name="sqlStr"></param>
/// <returns></returns>
public static MyDataRead GetDataRead(string sqlStr,CommandType cmdType=CommandType.Text,params MyParameter[] pras)
{
InitConnection();
MyDataRead dr = null;
MyCommand cmd = null;
try
{
cmd = new MyCommand(sqlStr, conn);
cmd.CommandType = cmdType;
dr = cmd.ExecuteReader();
}
catch (System.Exception ex)
{
MessageBox.Show(ex.Message);
}
return dr;
}
/// <summary>
/// 用Sql語句,參數列表對數據庫的
/// Insert,Update,Delete執行操作
/// </summary>
/// <param name="sql"></param>
/// <param name="mPars"></param>
/// <returns></returns>
public static int ExecuteNonQuery(string sql,CommandType cmdType=CommandType.Text, params MyParameter[] mPars)
{
InitConnection();
int nRet = 0;
MyCommand cmd = null;
try
{
cmd = new MyCommand(sql, conn);
cmd.CommandType = cmdType;
if(mPars.Length!=0)
{
cmd.Parameters.Clear();
cmd.Parameters.AddRange(mPars);
}
nRet =cmd.ExecuteNonQuery();
}
catch (System.Exception ex)
{
MessageBox.Show(ex.Message);
}
finally
{
cmd.Dispose();
conn.Close();
}
return nRet;
}
/// <summary>
/// 圖片(Image)格式轉為字節(byte[])格式
/// </summary>
/// <param name="_image"></param>
/// <returns></returns>
public static byte[] ImageToByte(Image _image)
{
MemoryStream ms = new MemoryStream();
_image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
return ms.ToArray();
}
/// <summary>
/// 字節(byte[])轉為圖片(Image)格式
/// </summary>
/// <param name="buff"></param>
/// <returns></returns>
public static Image BetyToImage(byte[] buff)
{
MemoryStream memoryStream = new MemoryStream(buff, 0, buff.Length);
memoryStream.Write(buff, 0, buff.Length);
Image image = null;
try
{
//字節數組轉成Image對象
image = Image.FromStream(memoryStream);
}
catch (Exception)
{
throw;
}
return image;
}
}
基本上有這幾個方法就能操作數據庫了.
特別要說的是GetDataRead()這個方法是要連接數據庫操作的,一般我用在數據遞歸中
最后遞歸完了手動關閉連接,其他的方法都是斷開連接操作的,函數返回前就關閉了連接,
所以在外面調用的時候就不用關閉數據庫連接了.
在寫個類繼承BaseADO類,在子類寫實際的數據庫操作方法
下面以修改數據庫數據為例;
/// <summary>
/// 更新指定id的數據庫數據
/// </summary>
/// <param name="stu">要更新的數據結構</param>
/// <param name="id">要更新的查詢id</param>
/// <returns></returns>
public static int UpdateAllData(STUDENT_INFO stu,string id)
{
string sql = "update {0} set mName=@name,mSex=@sex,mAge=@age,mTel=@tel,";
sql += "mFenZu =@fenzu,mBirthday=@birthday,mQQ=@qq,mAddess=@addess,";
sql += "mBeiZu =@beizu,mPicBytes=@picbytes where mID=@mid";
sql = string.Format(sql, MYTABLE_NAME);
//STUDENT_INFO stu = GetDataToStudentInfo();
MyParameter[] pars =
{
new MyParameter("@name",stu.name),
new MyParameter("@sex",stu.sex),
new MyParameter("@age",stu.age),
new MyParameter("@tel",stu.tel),
new MyParameter("@fenzu",stu.fenzu),
new MyParameter("@birthday",stu.birthday),
new MyParameter("@qq",stu.qq),
new MyParameter("@addess",stu.addess),
new MyParameter("@beizu",stu.beizu),
new MyParameter("@picbytes",stu.picBytes),
new MyParameter("@mid",id)
};
return ExecuteNonQuery(sql, mPars:pars);
}
是后調用的這個ExecuteNonQuery()方法的參數要注意,因中間還有一個參數有默認值,
所以要用指定參數名值的格式(形參名:實參名),不然是通不過的.