dbHelper类操作数据库
using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Data.SqlClient; namespace Test
{
public abstract class DbHelper
{
//数据库连接字符串(web.config来配置)
// <connectionStrings>
// <add name="strCon" connectionString="server=127.0.0.1;user id=sa; password=sa; database=dataBaseName;"/>
// </connectionStrings>
protected static string ConnectionString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
public DbHelper()
{ }
#region 公用方法 public static int GetMaxID(string FieldName, string TableName)
{
string strsql = "select max(" + FieldName + ")+1 from " + TableName;
object obj = GetSingle(strsql);
if (obj == null)
{
return 1;
}
else
{
return int.Parse(obj.ToString());
}
}
public static bool Exists(string strSql, params SqlParameter[] cmdParms)
{
object obj = GetSingle(strSql, cmdParms);
int cmdresult;
if ((Equals(obj, null)) || (Equals(obj, DBNull.Value)))
{
cmdresult = 0;
}
else
{
cmdresult = int.Parse(obj.ToString());
}
if (cmdresult == 0)
{
return false;
}
else
{
return true;
}
}
#endregion #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 (SqlConnection connection = new SqlConnection(ConnectionString))
{
using (SqlCommand cmd = new SqlCommand(SQLString, connection))
{
try
{
connection.Open();
int rows = cmd.ExecuteNonQuery();
return rows;
}
catch (SqlException E)
{
connection.Close();
throw new Exception(E.Message);
}
}
}
} /// <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 void ExecuteSqlTran(ArrayList SQLStringList)
{
using (SqlConnection conn = new SqlConnection(ConnectionString))
{
conn.Open();
SqlCommand cmd = new SqlCommand();
cmd.Connection = conn;
SqlTransaction tx = conn.BeginTransaction();
cmd.Transaction = tx;
try
{
for (int n = 0; n < SQLStringList.Count; n++)
{
string strsql = SQLStringList[n].ToString();
if (strsql.Trim().Length > 1)
{
cmd.CommandText = strsql;
cmd.ExecuteNonQuery();
}
}
tx.Commit();
}
catch (SqlException E)
{
tx.Rollback();
throw new Exception(E.Message);
}
}
}
/// <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 (SqlConnection connection = new SqlConnection(ConnectionString))
{
SqlCommand cmd = new SqlCommand(SQLString, connection);
SqlParameter myParameter = new SqlParameter("@content", SqlDbType.NText);
myParameter.Value = content;
cmd.Parameters.Add(myParameter);
try
{
connection.Open();
int rows = cmd.ExecuteNonQuery();
return rows;
}
catch (SqlException E)
{
throw new Exception(E.Message);
}
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 (SqlConnection connection = new SqlConnection(ConnectionString))
{
SqlCommand cmd = new SqlCommand(strSQL, connection);
SqlParameter myParameter = new SqlParameter("@fs", SqlDbType.Image);
myParameter.Value = fs;
cmd.Parameters.Add(myParameter);
try
{
connection.Open();
int rows = cmd.ExecuteNonQuery();
return rows;
}
catch (SqlException E)
{
throw new Exception(E.Message);
}
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 (SqlConnection connection = new SqlConnection(ConnectionString))
{
using (SqlCommand cmd = new SqlCommand(SQLString, connection))
{
try
{
connection.Open();
object obj = cmd.ExecuteScalar();
if ((Equals(obj, null)) || (Equals(obj, DBNull.Value)))
{
return null;
}
else
{
return obj;
}
}
catch (SqlException e)
{
connection.Close();
throw new Exception(e.Message);
}
}
}
}
/// <summary>
/// 执行查询语句，返回SqlDataReader
/// </summary>
/// <param name="strSQL">查询语句</param>
/// <returns>SqlDataReader</returns>
public static SqlDataReader ExecuteReader(string strSQL)
{
SqlConnection connection = new SqlConnection(ConnectionString);
SqlCommand cmd = new SqlCommand(strSQL, connection);
try
{
connection.Open();
SqlDataReader myReader = cmd.ExecuteReader();
return myReader;
}
catch (SqlException e)
{
throw new Exception(e.Message);
} }
/// <summary>
/// 执行查询语句，返回DataSet
/// </summary>
/// <param name="SQLString">查询语句</param>
/// <returns>DataSet</returns>
public static DataSet Query(string SQLString)
{
using (SqlConnection connection = new SqlConnection(ConnectionString))
{
DataSet ds = new DataSet();
try
{
connection.Open();
SqlDataAdapter command = new SqlDataAdapter(SQLString, connection);
command.Fill(ds, "ds");
}
catch (SqlException ex)
{
throw new Exception(ex.Message);
}
return ds;
}
} #endregion #region 执行带参数的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, params SqlParameter[] cmdParms)
{
using (SqlConnection connection = new SqlConnection(ConnectionString))
{
using (SqlCommand cmd = new SqlCommand())
{
try
{
PrepareCommand(cmd, connection, null, SQLString, cmdParms);
int rows = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
return rows;
}
catch (SqlException E)
{
throw new Exception(E.Message);
}
}
}
} /// <summary>
/// 执行多条SQL语句，实现数据库事务。
/// </summary>
/// <param name="SQLStringList">SQL语句的哈希表（key为sql语句，value是该语句的SqlParameter[]）</param>
public static void ExecuteSqlTran(Hashtable SQLStringList)
{
using (SqlConnection conn = new SqlConnection(ConnectionString))
{
conn.Open();
using (SqlTransaction trans = conn.BeginTransaction())
{
SqlCommand cmd = new SqlCommand();
try
{
//循环
foreach (DictionaryEntry myDE in SQLStringList)
{
string cmdText = myDE.Key.ToString();
SqlParameter[] cmdParms = (SqlParameter[])myDE.Value;
PrepareCommand(cmd, conn, trans, cmdText, cmdParms);
int val = cmd.ExecuteNonQuery();
cmd.Parameters.Clear(); trans.Commit();
}
}
catch
{
trans.Rollback();
throw;
}
}
}
} /// <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, params SqlParameter[] cmdParms)
{
using (SqlConnection connection = new SqlConnection(ConnectionString))
{
using (SqlCommand cmd = new SqlCommand())
{
try
{
PrepareCommand(cmd, connection, null, SQLString, cmdParms);
object obj = cmd.ExecuteScalar();
cmd.Parameters.Clear();
if ((Equals(obj, null)) || (Equals(obj, DBNull.Value)))
{
return null;
}
else
{
return obj;
}
}
catch (SqlException e)
{
throw new Exception(e.Message);
}
}
}
} /// <summary>
/// 执行查询语句，返回SqlDataReader
/// </summary>
/// <param name="strSQL">查询语句</param>
/// <returns>SqlDataReader</returns>
public static SqlDataReader ExecuteReader(string SQLString, params SqlParameter[] cmdParms)
{
SqlConnection connection = new SqlConnection(ConnectionString);
SqlCommand cmd = new SqlCommand();
try
{
PrepareCommand(cmd, connection, null, SQLString, cmdParms);
SqlDataReader myReader = cmd.ExecuteReader();
cmd.Parameters.Clear();
return myReader;
}
catch (SqlException e)
{
throw new Exception(e.Message);
} } /// <summary>
/// 执行查询语句，返回DataSet
/// </summary>
/// <param name="SQLString">查询语句</param>
/// <returns>DataSet</returns>
public static DataSet Query(string SQLString, params SqlParameter[] cmdParms)
{
using (SqlConnection connection = new SqlConnection(ConnectionString))
{
SqlCommand cmd = new SqlCommand();
PrepareCommand(cmd, connection, null, SQLString, cmdParms);
using (SqlDataAdapter da = new SqlDataAdapter(cmd))
{
DataSet ds = new DataSet();
try
{
da.Fill(ds, "ds");
cmd.Parameters.Clear();
}
catch (SqlException ex)
{
throw new Exception(ex.Message);
}
return ds;
}
}
} private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, string cmdText, SqlParameter[] 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 (SqlParameter parm in cmdParms)
cmd.Parameters.Add(parm);
}
} #endregion #region 存储过程操作 /// <summary>
/// 执行存储过程
/// </summary>
/// <param name="storedProcName">存储过程名</param>
/// <param name="parameters">存储过程参数</param>
/// <returns>SqlDataReader</returns>
public static SqlDataReader RunProcedure(string storedProcName, IDataParameter[] parameters)
{
SqlConnection connection = new SqlConnection(ConnectionString);
SqlDataReader returnReader;
connection.Open();
SqlCommand command = BuildQueryCommand(connection, storedProcName, parameters);
command.CommandType = CommandType.StoredProcedure;
returnReader = command.ExecuteReader();
return returnReader;
} /// <summary>
/// 执行存储过程
/// </summary>
/// <param name="storedProcName">存储过程名</param>
/// <param name="parameters">存储过程参数</param>
/// <param name="tableName">DataSet结果中的表名</param>
/// <returns>DataSet</returns>
public static DataSet RunProcedure(string storedProcName, IDataParameter[] parameters, string tableName)
{
using (SqlConnection connection = new SqlConnection(ConnectionString))
{
DataSet dataSet = new DataSet();
connection.Open();
SqlDataAdapter sqlDA = new SqlDataAdapter();
sqlDA.SelectCommand = BuildQueryCommand(connection, storedProcName, parameters);
sqlDA.Fill(dataSet, tableName);
connection.Close();
return dataSet;
}
} /// <summary>
/// 构建 SqlCommand 对象(用来返回一个结果集，而不是一个整数值)
/// </summary>
/// <param name="connection">数据库连接</param>
/// <param name="storedProcName">存储过程名</param>
/// <param name="parameters">存储过程参数</param>
/// <returns>SqlCommand</returns>
private static SqlCommand BuildQueryCommand(SqlConnection connection, string storedProcName, IDataParameter[] parameters)
{
SqlCommand command = new SqlCommand(storedProcName, connection);
command.CommandType = CommandType.StoredProcedure;
foreach (SqlParameter parameter in parameters)
{
command.Parameters.Add(parameter);
}
return command;
} /// <summary>
/// 执行存储过程，返回影响的行数
/// </summary>
/// <param name="storedProcName">存储过程名</param>
/// <param name="parameters">存储过程参数</param>
/// <param name="rowsAffected">影响的行数</param>
/// <returns></returns>
public static int RunProcedure(string storedProcName, IDataParameter[] parameters, out int rowsAffected)
{
using (SqlConnection connection = new SqlConnection(ConnectionString))
{
int result;
connection.Open();
SqlCommand command = BuildIntCommand(connection, storedProcName, parameters);
rowsAffected = command.ExecuteNonQuery();
result = (int)command.Parameters["ReturnValue"].Value;
//Connection.Close();
return result;
}
} /// <summary>
/// 创建 SqlCommand 对象实例(用来返回一个整数值)
/// </summary>
/// <param name="storedProcName">存储过程名</param>
/// <param name="parameters">存储过程参数</param>
/// <returns>SqlCommand 对象实例</returns>
private static SqlCommand BuildIntCommand(SqlConnection connection, string storedProcName, IDataParameter[] parameters)
{
SqlCommand command = BuildQueryCommand(connection, storedProcName, parameters);
command.Parameters.Add(new SqlParameter("ReturnValue",
SqlDbType.Int, 4, ParameterDirection.ReturnValue,
false, 0, 0, string.Empty, DataRowVersion.Default, null));
return command;
}
#endregion }
}
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