通用数据库操作辅助类DbHelper
http://www.cnblogs.com/yelaiju/archive/2010/09/22/1832916.html
使用方式
DbHelper db;
OpenFileDialog ofd = new OpenFileDialog();
ofd.Filter = " SQLite数据文件(*.db3;*.db;*.sqlite)|*.db3;*.db;*.sqlite " ;
if (ofd.ShowDialog() == DialogResult.OK)
{
txtDataSource.Text = ofd.FileName;
db = new DbHelper( " data source= " + txtDataSource.Text, DbProvider.Sqlite);
}
db.ReExNum(txtSql.Text);
接口
using System.Data;
using System.Collections.Generic;
using System.Data.Common;
///
/// 该类用于对数据库进行操作
/// Design by 火地晋
///
namespace System.Data
{
public interface IDbObject
{
///
/// 定义一个DataReader的列表，已备检索
///
List < DbDataReader > DataReaderList { get ; set ; }
///
///
///
DbConnection Connection { get ; set ; }
string ConnectionString { get ; set ; }
DbProvider DbProviderType { get ; set ; }
///
/// 返回执行操作成功的数目，使用注意，如果是存储过程，必须在存储过程后加上：select @@ROWCOUNT
///
///
///
///
int ReExNum( string strSql, params DbParameter[] parameters);
///
/// 返回结果的存储过程
///
///
///
///
DbDataReader ReSelectdr( string strSql, params DbParameter[] parameters);
///
/// 返回dateSet
///
///
///
///
///
DataSet ReSelectds( string strSql, string tableName, params DbParameter[] parameters);
DataTable ReSelectdtb( string strSql, params DbParameter[] parameters);
///
/// 通過存儲過程及自定義參數組查詢返回SqlDataAdapter對象
///
DbDataAdapter ReSelectdat( string strSql, params DbParameter[] parameters);
void ExSQL( string strSql, params DbParameter[] parameters);
///
/// 執行SQL查詢語句,返回記錄條數
///
///
///
int ReSelectNum( string strSql, params DbParameter[] parameters);
///
/// 使用SqlDataAdapter返回指定范围的数据
///
///
///
///
///
///
///
DataSet ReSelectds( string strSql, DbParameter[] parameters, int start, int maxRecord, string tableName);
///
/// 返回执行操作成功的数目，不关闭连接
///
///
///
///
int ReExNumNoClose( string strSql, params DbParameter[] parameters);
///
/// 返回执行操作成功的数目，不关闭连接，并返回出现的错误信息。
///
///
///
///
int ReExNumNoClose( string strSql, out string error, params DbParameter[] parameters);
///
/// 返回执行操作成功的数目，并返回发生的错误信息
///
///
///
///
int ReExNum( string strSql, out string error, params DbParameter[] parameters);
///
/// 返回执行操作结果的信息，如果返回为空则表示没错误，否则返回错误的信息。
///
///
///
///
string ReExStr( string strSql, params DbParameter[] parameters);
///
/// 如果数据库连接已关闭,则打开
///
///
bool OpenConnection();
///
/// 关闭数据库连接
///
void CloseConnection();
}
public enum DbProvider
{
Sql = 0 ,
Sqlite = 1 ,
OleDb = 2 ,
Oracle = 3 ,
MySql = 4
}
}
类
using System;
using System.Collections.Generic;
using System.Text;
using System.Data.Common;
namespace System.Data
{
public class DbHelper : IDbObject
{
#region 属性
public List < DbDataReader > DataReaderList { get ; set ; }
public DbConnection Connection { get ; set ; }
public string ConnectionString { get ; set ; }
public DbProvider DbProviderType { get ; set ; }
private DbProviderFactory dbFactory;
#endregion
#region 构造函数
public DbHelper()
{
DbHelperInstance(System.Configuration.ConfigurationManager.AppSettings[ " ConnectionString " ], DbProvider.Sql);
}
public DbHelper( string connectionString)
{
DbHelperInstance(connectionString, DbProvider.Sql);
}
public DbHelper(DbProvider dbProviderType)
{
DbHelperInstance(System.Configuration.ConfigurationManager.AppSettings[ " ConnectionString " ], dbProviderType);
}
public DbHelper( string connectionString, DbProvider dbProviderType)
{
DbHelperInstance(connectionString, dbProviderType);
}
///
/// 初始化
///
///
///
public void DbHelperInstance( string connectionString, DbProvider dbProviderType)
{
this .DbProviderType = dbProviderType;
this .ConnectionString = connectionString;
DataReaderList = new List < DbDataReader > ();
CreateFactory();
this .Connection = this .dbFactory.CreateConnection();
this .Connection.ConnectionString = this .ConnectionString;
}
#endregion
///
/// 创建数据操作工厂
///
private void CreateFactory()
{
switch (DbProviderType)
{
case DbProvider.Sql:
this .dbFactory = System.Data.SqlClient.SqlClientFactory.Instance;
break ;
case DbProvider.Sqlite:
this .dbFactory = System.Data.SQLite.SQLiteFactory.Instance;
break ;
case DbProvider.OleDb:
this .dbFactory = System.Data.OleDb.OleDbFactory.Instance;
break ;
case DbProvider.Oracle:
this .dbFactory = System.Data.OracleClient.OracleClientFactory.Instance;
break ;
case DbProvider.MySql:
this .dbFactory = MySql.Data.MySqlClient.MySqlClientFactory.Instance;
break ;
}
}
///
/// 创建操作对象
///
///
///
///
private DbCommand BuilderQueryCommand( string procNameOrExText, params DbParameter[] parameters)
{
if (parameters == null || parameters.Length == 0 )
{
DbCommand command = this .dbFactory.CreateCommand();
command.CommandText = procNameOrExText;
command.Connection = this .Connection;
return command;
}
if (procNameOrExText.IndexOf( ' @ ' ) > 0 ) // 存储过程
{
return BuilderQueryCommandText(procNameOrExText, parameters);
}
else
{
return BuilderQueryCommandStorPro(procNameOrExText, parameters);
}
}
///
/// 根据存储过程名称和参数生成对应的SQL命令对象
///
///
///
///
private DbCommand BuilderQueryCommandStorPro( string strSql, params DbParameter[] parameters)
{
DbCommand command = this .dbFactory.CreateCommand();
command.CommandText = strSql;
command.CommandType = CommandType.StoredProcedure;
command.Connection = this .Connection;
if (parameters != null )
{
foreach (DbParameter p in parameters)
{
command.Parameters.Add(p);
}
}
return command;
}
private DbCommand BuilderQueryCommandText( string strSql, params DbParameter[] parameters)
{
DbCommand command = this .dbFactory.CreateCommand();
command.CommandText = strSql;
command.Connection = this .Connection;
if (parameters != null )
{
foreach (DbParameter p in parameters)
{
command.Parameters.Add(p);
}
}
return command;
}
public DbParameter CreateDbParameter( string parameterName)
{
return CreateDbParameter(parameterName, DBNull.Value, DbType.Object, 0 , ParameterDirection.Input);
}
public DbParameter CreateDbParameter( string parameterName, object value)
{
return CreateDbParameter(parameterName, value, DbType.Object, 0 , ParameterDirection.Input);
}
public DbParameter CreateDbParameter( string parameterName, object value, DbType dbType)
{
return CreateDbParameter(parameterName,value,dbType, 0 ,ParameterDirection.Input);
}
public DbParameter CreateDbParameter( string parameterName, object value, DbType dbType, int size)
{
return CreateDbParameter(parameterName,value,dbType,size,ParameterDirection.Input);
}
public DbParameter CreateDbParameter( string parameterName, object value, DbType dbType, int size, ParameterDirection parameterDirection)
{
DbParameter pat = this .dbFactory.CreateParameter();
pat.ParameterName = parameterName;
pat.Value = value;
pat.DbType = dbType;
pat.Size = size;
pat.Direction = parameterDirection;
return pat;
}
///
/// 返回执行操作成功的数目，使用注意，如果是存储过程，必须在存储过程后加上：select @@ROWCOUNT
///
///
///
///
public int ReExNum( string strSql, params DbParameter[] parameters)
{
int effect = 0 ;
if ( ! OpenConnection()) return - 1 ;
DbTransaction trans = Connection.BeginTransaction();
try
{
DbCommand cmd = BuilderQueryCommand(strSql, parameters);
cmd.Transaction = trans;
// 根据是否为存储过程来执行不同的处理
if (cmd.CommandType == CommandType.StoredProcedure)
{
object result = cmd.ExecuteScalar();
effect = result == null ? - 1 : Convert.ToInt16(result);
}
else
{
effect = cmd.ExecuteNonQuery();
}
trans.Commit();
return effect;
}
catch
{
trans.Rollback();
Connection.Close();
return - 1 ;
}
finally
{
Connection.Close();
}
}
///
/// 返回结果的存储过程
///
///
///
///
public DbDataReader ReSelectdr( string strSql, params DbParameter[] parameters)
{
try
{
DbDataReader reader;
if ( ! OpenConnection()) return null ;
DbCommand cmd = BuilderQueryCommand(strSql, parameters);
reader = cmd.ExecuteReader(CommandBehavior.CloseConnection); // 在dr关闭之后,就不需要进行cnn的关闭操作了
DataReaderList.Add(reader); // 添加进dr列表,已备检索
return reader;
}
catch
{
return null ;
}
}
///
/// 返回dateSet
///
///
///
///
///
public DataSet ReSelectds( string strSql, string tableName, params DbParameter[] parameters)
{
try
{
DataSet ds = new DataSet();
if ( ! OpenConnection()) return null ;
DbDataAdapter myDa = this .dbFactory.CreateDataAdapter();
myDa.SelectCommand = BuilderQueryCommand(strSql, parameters);
myDa.Fill(ds, tableName);
return ds;
}
catch
{
return null ;
}
finally
{
Connection.Close();
}
}
public DataTable ReSelectdtb( string strSql, params DbParameter[] parameters)
{
try
{
DataTable dt = new DataTable();
if ( ! OpenConnection()) return null ;
DbDataAdapter myDa = this .dbFactory.CreateDataAdapter();
myDa.SelectCommand = BuilderQueryCommand(strSql, parameters);
myDa.Fill(dt);
return dt;
}
catch
{
return null ;
}
finally
{
Connection.Close();
}
}
///
/// 通過存儲過程及自定義參數組查詢返回SqlDataAdapter對象
///
public DbDataAdapter ReSelectdat( string strSql, params DbParameter[] parameters)
{
if ( ! OpenConnection()) return null ;
try
{
DbCommand cmd = BuilderQueryCommand(strSql, parameters);
DbDataAdapter myDa = this .dbFactory.CreateDataAdapter();
myDa.SelectCommand = cmd;
return myDa;
}
catch
{
Connection.Close();
return null ;
}
}
public void ExSQL( string strSql, params DbParameter[] parameters)
{
if ( ! OpenConnection()) return ;
DbTransaction trans = Connection.BeginTransaction();
try
{
DbCommand cmd = BuilderQueryCommand(strSql, parameters);
cmd.Transaction = trans;
cmd.ExecuteNonQuery();
trans.Commit();
}
catch
{
trans.Rollback();
Connection.Close();
return ;
}
finally
{
Connection.Close();
}
}
///
/// 執行SQL查詢語句,返回記錄條數
///
///
///
public int ReSelectNum( string strSql, params DbParameter[] parameters)
{
int effect = 0 ;
try
{
DbDataReader dr = ReSelectdr(strSql, parameters);
if (dr.Read())
{
effect = Convert.ToInt32(dr.GetValue( 0 ));
}
return effect;
}
catch
{
return effect;
}
}
///
/// 使用SqlDataAdapter返回指定范围的数据
///
///
///
///
///
///
///
public DataSet ReSelectds( string strSql, DbParameter[] parameters, int start, int maxRecord, string tableName)
{
try
{
DataSet ds = new DataSet();
OpenConnection();
DbDataAdapter myDa = this .dbFactory.CreateDataAdapter();
myDa.SelectCommand = BuilderQueryCommand(strSql, parameters);
myDa.Fill(ds, start, maxRecord, tableName);
return ds;
}
catch
{
Connection.Close();
return null ;
}
finally
{
Connection.Close();
}
}
///
/// 返回执行操作成功的数目，不关闭连接
///
///
///
///
public int ReExNumNoClose( string strSql, params DbParameter[] parameters)
{
int effect = 0 ;
if ( ! OpenConnection()) return - 1 ;
DbTransaction trans = Connection.BeginTransaction();
try
{
DbCommand cmd = BuilderQueryCommand(strSql, parameters);
cmd.Transaction = trans;
// 根据是否为存储过程来执行不同的处理
if (cmd.CommandType == CommandType.StoredProcedure)
{
object result = cmd.ExecuteScalar();
effect = result == null ? - 1 : Convert.ToInt16(result);
}
else
{
effect = cmd.ExecuteNonQuery();
}
trans.Commit();
return effect;
}
catch
{
trans.Rollback();
return effect;
}
}
///
/// 返回执行操作成功的数目，不关闭连接，并返回出现的错误信息。
///
///
///
///
public int ReExNumNoClose( string strSql, out string error, params DbParameter[] parameters)
{
int effect = 0 ;
error = "" ;
if ( ! OpenConnection()) return - 1 ;
DbTransaction trans = Connection.BeginTransaction();
try
{
DbCommand cmd = BuilderQueryCommand(strSql, parameters);
cmd.Transaction = trans;
if (cmd.CommandType == CommandType.StoredProcedure)
{
object result = cmd.ExecuteScalar();
effect = result == null ? - 1 : Convert.ToInt16(result);
}
else
{
effect = cmd.ExecuteNonQuery();
}
effect = cmd.ExecuteNonQuery();
trans.Commit();
return effect;
}
catch (Exception ex)
{
trans.Rollback();
error = ex.Message;
return effect;
}
}
///
/// 返回执行操作成功的数目，并返回发生的错误信息
///
///
///
///
public int ReExNum( string strSql, out string error, params DbParameter[] parameters)
{
int effect = 0 ;
error = "" ;
if ( ! OpenConnection()) return - 1 ;
DbTransaction trans = Connection.BeginTransaction();
try
{
DbCommand cmd = BuilderQueryCommand(strSql, parameters);
cmd.Transaction = trans;
if (cmd.CommandType == CommandType.StoredProcedure)
{
object result = cmd.ExecuteScalar();
effect = result == null ? - 1 : Convert.ToInt16(result);
}
else
{
effect = cmd.ExecuteNonQuery();
}
trans.Commit();
return effect;
}
catch (Exception ex)
{
trans.Rollback();
error = ex.Message;
return effect;
}
finally
{
Connection.Close();
}
}
///
/// 返回执行操作结果的信息，如果返回为空则表示没错误，否则返回错误的信息。
///
///
///
///
public string ReExStr( string strSql, params DbParameter[] parameters)
{
string error = string .Empty;
int effect = 0 ;
if ( ! OpenConnection()) return null ;
DbTransaction trans = Connection.BeginTransaction();
try
{
DbCommand cmd = BuilderQueryCommand(strSql, parameters);
cmd.Transaction = trans;
effect = cmd.ExecuteNonQuery();
trans.Commit();
if (effect == 0 )
{
error = " 操作成功记录数为0，请检查意外的错误。 " + " sql语句： " + strSql;
}
else
{
error = "" ;
}
}
catch (Exception ex)
{
trans.Rollback();
error = " sql语句： " + strSql + " 错误信息： " + ex.Message;
}
finally
{
Connection.Close();
}
return error;
}
///
/// 如果数据库连接已关闭,则打开
///
///
public bool OpenConnection()
{
if (Connection.State == ConnectionState.Closed)
{
try
{
Connection.Open();
}
catch
{
return false ;
}
}
return true ;
}
public void CloseConnection()
{
Connection.Close();
}
}
}