下面介绍两种执行SQL命令的方法，并作出相应地总结，第一种介绍一种常规用法，下面进行做简要地分析，首先我们需要执行打开数据库操作首先创建一个MySqlConnection对象，在其构造函数中传入一个连接字符串，然后执行Open操作打开数据库，在正确打开数据库之后我们才能进行相关的动作，在ExecuteSQL这个函数中，
我们执行MySqlCommand myCmd = new MySqlCommand(CmdString, conn)，从而创建MySqlCommand对象，其中传入的两个参数分别为sql命令和第一步建立的MySqlConnection对象，然后执行int Cmd = myCmd.ExecuteNonQuery()这一句执行相应的命令，并返回受影响的行数，最后我们需要关闭数据库连接，并释放非托管资源，从而完成整个数据库操作的过程;这个是比较常规的一种做法，也是我们使用比较多的一种形式。
public class DataBaseMySqlHelper
{
string connstr;
MySqlConnection conn;
//Server=xxxxxxx;Database=xxxxxxx;Uid=xxxxxxx;Pwd=xxxxxxx;CharSet=gbk;
//Server=xxx.xx.xxx.xx;Database=MSUP;Uid=dvision;Pwd=dvision;Port=xxxx;allow zero datetime = true;
MainWindow _MainWindow;
public DataBaseMySqlHelper(MainWindow mainWindow)
{
_MainWindow = mainWindow;
connstr = _MainWindow._ConfigInfo.MySqlConnectionStrings;
}
public DataBaseMySqlHelper(MainWindow mainWindow, string connectionString)
{
_MainWindow = mainWindow;
connstr = connectionString;
}
/// <summary>
/// 打开数据库连接
/// </summary>
void Open()
{
try
{
conn = new MySqlConnection(connstr);
conn.Open();
}
catch (Exception ex)
{
System.Windows.Forms.MessageBox.Show(ex.Message);
}
}
/// <summary>
/// 关闭数据库连接
/// </summary>
void Close()
{
conn.Close();
}
/// <summary>
/// 返回影响数据库的行数
/// </summary>
/// <param name="CmdString"></param>
/// <returns></returns>
public int ExecuteSQL(string CmdString)
{
try
{
Open();
MySqlCommand myCmd = new MySqlCommand(CmdString, conn);
int Cmd = myCmd.ExecuteNonQuery();
Close();
return Cmd;
}
catch (Exception ex)
{
_MainWindow.ShowErrorMessage(" MySql数据库查询失败!");
return 0;
}
}
/// <summary>
/// 返回数据表
/// </summary>
/// <param name="CmdString"></param>
/// <returns></returns>
public DataTable GetDataTable(string CmdString)
{
try
{
Open();
DataSet myDs = new DataSet();
MySqlDataAdapter myDa = new MySqlDataAdapter();
myDa.SelectCommand = new MySqlCommand(CmdString, conn);
myDa.Fill(myDs);
Close();
return myDs.Tables[0];
}
catch (Exception e)
{
_MainWindow.ShowErrorMessage(" MySql数据库查询失败!");
return null;
}
}
}
第二种方式，这里也贴出关键代码并做简要的分析：这里的关键是MySqlParameter[]数组的使用，我们在执行SQL语句的时候 DbHelperMySQL.ExecuteSql(strSql.ToString(),parameters);这里的parameters就是MySqlParameter[]数组，里面存储的是每个字段的数据，我们将在下面的代码中展示parameters的内容，
/// <summary>
/// 增加一条数据
/// </summary>
public void Add(Maticsoft.Model.cameradetail model)
{
StringBuilder strSql=new StringBuilder();
strSql.Append("insert into cameradetail_gis(");
strSql.Append("EncodeDeviceUsername,MatrixIP,EncodeDevicePassword,id,Name,DisplayName,Location,Longitude,Latitude,CameraActive,ServerID,ForwardSvrIP,ForwardSvrPort,EncodeDeviceIP,EncodeDevicePort,CameraType,CameraModel,DeviceChannel,MatrixPort,MatrixChannelNum,VideoStoreServerIP,VideoStoreServerPort,VideoStoreServerUserID,VideoStoreServerPassword,EncodeDeviceModelNum,EncodeDeviceModelName,CameraInstallAddress,CameraStatus)");
strSql.Append(" values (");
strSql.Append("@EncodeDeviceUsername,@MatrixIP,@EncodeDevicePassword,@id,@Name,@DisplayName,@Location,@Longitude,@Latitude,@CameraActive,@ServerID,@ForwardSvrIP,@ForwardSvrPort,@EncodeDeviceIP,@EncodeDevicePort,@CameraType,@CameraModel,@DeviceChannel,@MatrixPort,@MatrixChannelNum,@VideoStoreServerIP,@VideoStoreServerPort,@VideoStoreServerUserID,@VideoStoreServerPassword,@EncodeDeviceModelNum,@EncodeDeviceModelName,@CameraInstallAddress,@CameraStatus)");
MySqlParameter[] parameters = {
new MySqlParameter("@EncodeDeviceUsername", MySqlDbType.VarChar,64),
new MySqlParameter("@MatrixIP", MySqlDbType.VarChar,16),
new MySqlParameter("@EncodeDevicePassword", MySqlDbType.VarChar,64),
new MySqlParameter("@id", MySqlDbType.VarChar,14),
new MySqlParameter("@Name", MySqlDbType.VarChar,100),
new MySqlParameter("@DisplayName", MySqlDbType.VarChar,100),
new MySqlParameter("@Location", MySqlDbType.VarChar,250),
new MySqlParameter("@Longitude", MySqlDbType.VarChar,16),
new MySqlParameter("@Latitude", MySqlDbType.VarChar,16),
new MySqlParameter("@CameraActive", MySqlDbType.Int32,11),
new MySqlParameter("@ServerID", MySqlDbType.VarChar,16),
new MySqlParameter("@ForwardSvrIP", MySqlDbType.VarChar,16),
new MySqlParameter("@ForwardSvrPort", MySqlDbType.VarChar,16),
new MySqlParameter("@EncodeDeviceIP", MySqlDbType.VarChar,16),
new MySqlParameter("@EncodeDevicePort", MySqlDbType.VarChar,6),
new MySqlParameter("@CameraType", MySqlDbType.VarChar,6),
new MySqlParameter("@CameraModel", MySqlDbType.VarChar,6),
new MySqlParameter("@DeviceChannel", MySqlDbType.VarChar,12),
new MySqlParameter("@MatrixPort", MySqlDbType.VarChar,6),
new MySqlParameter("@MatrixChannelNum", MySqlDbType.VarChar,14),
new MySqlParameter("@VideoStoreServerIP", MySqlDbType.VarChar,16),
new MySqlParameter("@VideoStoreServerPort", MySqlDbType.VarChar,6),
new MySqlParameter("@VideoStoreServerUserID", MySqlDbType.VarChar,50),
new MySqlParameter("@VideoStoreServerPassword", MySqlDbType.VarChar,20),
new MySqlParameter("@EncodeDeviceModelNum", MySqlDbType.VarChar,6),
new MySqlParameter("@EncodeDeviceModelName", MySqlDbType.VarChar,50),
new MySqlParameter("@CameraInstallAddress", MySqlDbType.VarChar,250),
new MySqlParameter("@CameraStatus", MySqlDbType.Int32,11)};
parameters[0].Value = model.EncodeDeviceUsername;
parameters[1].Value = model.MatrixIP;
parameters[2].Value = model.EncodeDevicePassword;
parameters[3].Value = model.id;
parameters[4].Value = model.Name;
parameters[5].Value = model.DisplayName;
parameters[6].Value = model.Location;
parameters[7].Value = model.Longitude;
parameters[8].Value = model.Latitude;
parameters[9].Value = model.CameraActive;
parameters[10].Value = model.ServerID;
parameters[11].Value = model.ForwardSvrIP;
parameters[12].Value = model.ForwardSvrPort;
parameters[13].Value = model.EncodeDeviceIP;
parameters[14].Value = model.EncodeDevicePort;
parameters[15].Value = model.CameraType;
parameters[16].Value = model.CameraModel;
parameters[17].Value = model.DeviceChannel;
parameters[18].Value = model.MatrixPort;
parameters[19].Value = model.MatrixChannelNum;
parameters[20].Value = model.VideoStoreServerIP;
parameters[21].Value = model.VideoStoreServerPort;
parameters[22].Value = model.VideoStoreServerUserID;
parameters[23].Value = model.VideoStoreServerPassword;
parameters[24].Value = model.EncodeDeviceModelNum;
parameters[25].Value = model.EncodeDeviceModelName;
parameters[26].Value = model.CameraInstallAddress;
parameters[27].Value = model.CameraStatus;
DbHelperMySQL.ExecuteSql(strSql.ToString(),parameters);
}
这里我们重点来关注DbHelperMySQL.ExecuteSql(strSql.ToString(),parameters)这个函数，函数的源码如下：
这里面有一个重要的函数PrepareCommand(cmd, connection, null, SQLString, cmdParms)，我们这里也贴出相应地源码，并做简要的分析：
这个函数首先是打开数据库连接，这里面最重要就是讲cmdParms里面的参数一个个添加到cmd.Parameters中，然后执行 int rows = cmd.ExecuteNonQuery();命令来执行相应的操作，这是一种决然不同的思路，我们在使用的时候可以考虑这两种方式来进行数据库的插入操作！
private static void PrepareCommand(MySqlCommand cmd, MySqlConnection conn, MySqlTransaction trans, string cmdText, MySqlParameter[] cmdParms)
{
if (conn.State != ConnectionState.Open)
conn.Open();
cmd.Connection = conn;
cmd.CommandText = cmdText;
if (trans != null)
cmd.Transaction = trans;
cmd.CommandType = CommandType.Text;//cmdType;
if (cmdParms != null)
{
foreach (MySqlParameter parameter in cmdParms)
{
if ((parameter.Direction == ParameterDirection.InputOutput || parameter.Direction == ParameterDirection.Input) &&
(parameter.Value == null))
{
parameter.Value = DBNull.Value;
}
cmd.Parameters.Add(parameter);
}
}
}
#endregion
/// <summary>
/// 执行SQL语句，返回影响的记录数
/// </summary>
/// <param name="SQLString">SQL语句</param>
/// <returns>影响的记录数</returns>
public static int ExecuteSql(string SQLString, params MySqlParameter[] cmdParms)
{
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
using (MySqlCommand cmd = new MySqlCommand())
{
try
{
PrepareCommand(cmd, connection, null, SQLString, cmdParms);
int rows = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
return rows;
}
catch (MySql.Data.MySqlClient.MySqlException e)
{
throw e;
}
}
}
}
#region 执行简单SQL语句
/// <summary>
/// 执行SQL语句，返回影响的记录数
/// </summary>
/// <param name="SQLString">SQL语句</param>
/// <returns>影响的记录数</returns>
public static int ExecuteSql(string SQLString)
{
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
using (MySqlCommand cmd = new MySqlCommand(SQLString, connection))
{
try
{
connection.Open();
int rows = cmd.ExecuteNonQuery();
return rows;
}
catch (MySql.Data.MySqlClient.MySqlException e)
{
connection.Close();
throw e;
}
}
}
}
public static int ExecuteSqlByTime(string SQLString, int Times)
{
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
using (MySqlCommand cmd = new MySqlCommand(SQLString, connection))
{
try
{
connection.Open();
cmd.CommandTimeout = Times;
int rows = cmd.ExecuteNonQuery();
return rows;
}
catch (MySql.Data.MySqlClient.MySqlException e)
{
connection.Close();
throw e;
}
}
}
}
/// <summary>
/// 执行MySql和Oracle滴混合事务
/// </summary>
/// <param name="list">SQL命令行列表</param>
/// <param name="oracleCmdSqlList">Oracle命令行列表</param>
/// <returns>执行结果 0-由于SQL造成事务失败 -1 由于Oracle造成事务失败 1-整体事务执行成功</returns>
public static int ExecuteSqlTran(List<CommandInfo> list, List<CommandInfo> oracleCmdSqlList)
{
using (MySqlConnection conn = new MySqlConnection(connectionString))
{
conn.Open();
MySqlCommand cmd = new MySqlCommand();
cmd.Connection = conn;
MySqlTransaction tx = conn.BeginTransaction();
cmd.Transaction = tx;
try
{
foreach (CommandInfo myDE in list)
{
string cmdText = myDE.CommandText;
MySqlParameter[] cmdParms = (MySqlParameter[])myDE.Parameters;
PrepareCommand(cmd, conn, tx, cmdText, cmdParms);
if (myDE.EffentNextType == EffentNextType.SolicitationEvent)
{
if (myDE.CommandText.ToLower().IndexOf("count(") == -1)
{
tx.Rollback();
throw new Exception("违背要求"+myDE.CommandText+"必须符合select count(..的格式");
//return 0;
}
object obj = cmd.ExecuteScalar();
bool isHave = false;
if (obj == null && obj == DBNull.Value)
{
isHave = false;
}
isHave = Convert.ToInt32(obj) > 0;
if (isHave)
{
//引发事件
myDE.OnSolicitationEvent();
}
}
if (myDE.EffentNextType == EffentNextType.WhenHaveContine || myDE.EffentNextType == EffentNextType.WhenNoHaveContine)
{
if (myDE.CommandText.ToLower().IndexOf("count(") == -1)
{
tx.Rollback();
throw new Exception("SQL:违背要求" + myDE.CommandText + "必须符合select count(..的格式");
//return 0;
}
object obj = cmd.ExecuteScalar();
bool isHave = false;
if (obj == null && obj == DBNull.Value)
{
isHave = false;
}
isHave = Convert.ToInt32(obj) > 0;
if (myDE.EffentNextType == EffentNextType.WhenHaveContine && !isHave)
{
tx.Rollback();
throw new Exception("SQL:违背要求" + myDE.CommandText + "返回值必须大于0");
//return 0;
}
if (myDE.EffentNextType == EffentNextType.WhenNoHaveContine && isHave)
{
tx.Rollback();
throw new Exception("SQL:违背要求" + myDE.CommandText + "返回值必须等于0");
//return 0;
}
continue;
}
int val = cmd.ExecuteNonQuery();
if (myDE.EffentNextType == EffentNextType.ExcuteEffectRows && val == 0)
{
tx.Rollback();
throw new Exception("SQL:违背要求" + myDE.CommandText + "必须有影响行");
//return 0;
}
cmd.Parameters.Clear();
}
string oraConnectionString = PubConstant.GetConnectionString("ConnectionStringPPC");
bool res = OracleHelper.ExecuteSqlTran(oraConnectionString, oracleCmdSqlList);
if (!res)
{
tx.Rollback();
throw new Exception("执行失败");
// return -1;
}
tx.Commit();
return 1;
}
catch (MySql.Data.MySqlClient.MySqlException e)
{
tx.Rollback();
throw e;
}
catch (Exception e)
{
tx.Rollback();
throw e;
}
}
}
/// <summary>
/// 执行多条SQL语句，实现数据库事务。
/// </summary>
/// <param name="SQLStringList">多条SQL语句</param>
public static int ExecuteSqlTran(List<String> SQLStringList)
{
using (MySqlConnection conn = new MySqlConnection(connectionString))
{
conn.Open();
MySqlCommand cmd = new MySqlCommand();
cmd.Connection = conn;
MySqlTransaction tx = conn.BeginTransaction();
cmd.Transaction = tx;
try
{
int count = 0;
for (int n = 0; n < SQLStringList.Count; n++)
{
string strsql = SQLStringList[n];
if (strsql.Trim().Length > 1)
{
cmd.CommandText = strsql;
count += cmd.ExecuteNonQuery();
}
}
tx.Commit();
return count;
}
catch
{
tx.Rollback();
return 0;
}
}
}
/// <summary>
/// 执行带一个存储过程参数的的SQL语句。
/// </summary>
/// <param name="SQLString">SQL语句</param>
/// <param name="content">参数内容,比如一个字段是格式复杂的文章，有特殊符号，可以通过这个方式添加</param>
/// <returns>影响的记录数</returns>
public static int ExecuteSql(string SQLString, string content)
{
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
MySqlCommand cmd = new MySqlCommand(SQLString, connection);
MySql.Data.MySqlClient.MySqlParameter myParameter = new MySql.Data.MySqlClient.MySqlParameter("@content", SqlDbType.NText);
myParameter.Value = content;
cmd.Parameters.Add(myParameter);
try
{
connection.Open();
int rows = cmd.ExecuteNonQuery();
return rows;
}
catch (MySql.Data.MySqlClient.MySqlException e)
{
throw e;
}
finally
{
cmd.Dispose();
connection.Close();
}
}
}
/// <summary>
/// 执行带一个存储过程参数的的SQL语句。
/// </summary>
/// <param name="SQLString">SQL语句</param>
/// <param name="content">参数内容,比如一个字段是格式复杂的文章，有特殊符号，可以通过这个方式添加</param>
/// <returns>影响的记录数</returns>
public static object ExecuteSqlGet(string SQLString, string content)
{
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
MySqlCommand cmd = new MySqlCommand(SQLString, connection);
MySql.Data.MySqlClient.MySqlParameter myParameter = new MySql.Data.MySqlClient.MySqlParameter("@content", SqlDbType.NText);
myParameter.Value = content;
cmd.Parameters.Add(myParameter);
try
{
connection.Open();
object obj = cmd.ExecuteScalar();
if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
{
return null;
}
else
{
return obj;
}
}
catch (MySql.Data.MySqlClient.MySqlException e)
{
throw e;
}
finally
{
cmd.Dispose();
connection.Close();
}
}
}
/// <summary>
/// 向数据库里插入图像格式的字段(和上面情况类似的另一种实例)
/// </summary>
/// <param name="strSQL">SQL语句</param>
/// <param name="fs">图像字节,数据库的字段类型为image的情况</param>
/// <returns>影响的记录数</returns>
public static int ExecuteSqlInsertImg(string strSQL, byte[] fs)
{
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
MySqlCommand cmd = new MySqlCommand(strSQL, connection);
MySql.Data.MySqlClient.MySqlParameter myParameter = new MySql.Data.MySqlClient.MySqlParameter("@fs", SqlDbType.Image);
myParameter.Value = fs;
cmd.Parameters.Add(myParameter);
try
{
connection.Open();
int rows = cmd.ExecuteNonQuery();
return rows;
}
catch (MySql.Data.MySqlClient.MySqlException e)
{
throw e;
}
finally
{
cmd.Dispose();
connection.Close();
}
}
}
/// <summary>
///执行一条计算查询结果语句，返回查询结果(object)。
/// </summary>
///<param name="SQLString">计算查询结果语句</param>
///<returns>查询结果（object）</returns>
public static object GetSingle(string SQLString)
{
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
using (MySqlCommand cmd = new MySqlCommand(SQLString, connection))
{
try
{
connection.Open();
object obj = cmd.ExecuteScalar();
if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
{
return null;
}
else
{
return obj;
}
}
catch (MySql.Data.MySqlClient.MySqlException e)
{
connection.Close();
throw e;
}
}
}
}
public static object GetSingle(string SQLString, int Times)
{
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
using (MySqlCommand cmd = new MySqlCommand(SQLString, connection))
{
try
{
connection.Open();
cmd.CommandTimeout = Times;
object obj = cmd.ExecuteScalar();
if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
{
return null;
}
else
{
return obj;
}
}
catch (MySql.Data.MySqlClient.MySqlException e)
{
connection.Close();
throw e;
}
}
}
}
/// <summary>
/// 执行查询语句，返回MySqlDataReader ( 注意：调用该方法后，一定要对MySqlDataReader进行Close )
/// </summary>
/// <param name="strSQL">查询语句</param>
/// <returns>MySqlDataReader</returns>
public static MySqlDataReader ExecuteReader(string strSQL)
{
MySqlConnection connection = new MySqlConnection(connectionString);
MySqlCommand cmd = new MySqlCommand(strSQL, connection);
try
{
connection.Open();
MySqlDataReader myReader = cmd.ExecuteReader(CommandBehavior.CloseCon 声明：本文内容来源于网络，版权归原作者所有，内容由互联网用户自发贡献自行上传，本网站不拥有所有权，未作人工编辑处理，也不承担相关法律责任。如果您发现有涉嫌版权的内容，欢迎发送邮件至：notice#nhooo.com（发邮件时，请将#更换为@）进行举报，并提供相关证据，一经查实，本站将立刻删除涉嫌侵权内容。