我们在软件开发过程中,数据库是一个永久不变的话题,但是根据软件架构与客户要求的不同我们会选择不同的数据库,在C#中不同数据库操作编写代码不尽相同,下面提供一种通用的数据库操作方案,只需要根据config的配置就可以动态的选择不同的数据库.
在配置文件中providerName指定不同的数据库类型.
<connectionStrings>
<add name="ConnectionString" connectionString=" ..." providerName="System.Data.OleDb" />
<add name="ConnectionString" connectionString=" ..." providerName="System.Data.SqlClient" />
</connectionStrings>
代码如下:
using System;
using System.Collections;
using System.Collections.Specialized;
using System.Data;
using System.Configuration;
using System.Data.Common;
namespace DataBase
{
/// <summary>
/// 数据访问基础类
/// </summary>
class DataHelper
{
protected static string connectionString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
DbProviderFactory provider;
public DataHelper()
{
provider = DbProviderFactories.GetFactory(ConfigurationManager.ConnectionStrings["ConnectionString"].ProviderName);
}
#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 int ExecuteSql(string SQLString)
{
using (DbConnection connection = provider.CreateConnection())
{
connection.ConnectionString = connectionString;
using (DbCommand cmd = provider.CreateCommand())
{
cmd.Connection = connection;
cmd.CommandText = SQLString;
try
{
connection.Open();
int rows = cmd.ExecuteNonQuery();
return rows;
}
catch (DbException E)
{
connection.Close();
connection.Dispose();
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 void ExecuteSqlTran(ArrayList SQLStringList)
{
using (DbConnection conn = provider.CreateConnection())
{
conn.ConnectionString = connectionString;
conn.Open();
using (DbCommand cmd = provider.CreateCommand())
{
cmd.Connection = conn;
using (DbTransaction 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 (DbException ex)
{
tx.Rollback();
conn.Close();
conn.Dispose();
throw ex;
}
}
}
}
}
/// <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 object GetSingle(string SQLString)
{
using (DbConnection connection = provider.CreateConnection())
{
connection.ConnectionString = connectionString;
using (DbCommand cmd = provider.CreateCommand())
{
cmd.Connection = connection;
cmd.CommandText = SQLString;
try
{
connection.Open();
object obj = cmd.ExecuteScalar();
if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
{
return null;
}
else
{
return obj;
}
}
catch (DbException e)
{
connection.Close();
connection.Dispose();
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 DbDataReader ExecuteReader(string strSQL)
{
DbConnection connection = provider.CreateConnection();
connection.ConnectionString = connectionString;
DbCommand cmd = provider.CreateCommand();
cmd.Connection = connection;
cmd.CommandText = strSQL;
try
{
connection.Open();
DbDataReader myReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
return myReader;
}
catch (System.Data.Common.DbException e)
{
connection.Close();
connection.Dispose();
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 DataSet GetDataSet(string SQLString)
{
using (DbConnection connection = provider.CreateConnection())
{
connection.ConnectionString = connectionString;
using (DbCommand cmd = provider.CreateCommand())
{
cmd.Connection = connection;
cmd.CommandText = SQLString;
try
{
DataSet ds = new DataSet();
DbDataAdapter adapter = provider.CreateDataAdapter();
adapter.SelectCommand = cmd;
adapter.Fill(ds, "ds");
return ds;
}
catch (DbException ex)
{
connection.Close();
connection.Dispose();
throw new Exception(ex.Message);
}
}
}
}
#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 int ExecuteSql(string SQLString, DbParameter[] cmdParms)
{
using (DbConnection connection = provider.CreateConnection())
{
connection.ConnectionString = connectionString;
using (DbCommand cmd = provider.CreateCommand())
{
cmd.Connection = connection;
cmd.CommandText = SQLString;
try
{
PrepareCommand(cmd, connection, null, SQLString, cmdParms);
int rows = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
return rows;
}
catch (DbException E)
{
connection.Close();
connection.Dispose();
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 void ExecuteSqlTran(Hashtable SQLStringList)
{
using (DbConnection conn = provider.CreateConnection())
{
conn.ConnectionString = connectionString;
conn.Open();
using (DbTransaction trans = conn.BeginTransaction())
{
using (DbCommand cmd = provider.CreateCommand())
{
try
{
//循环
foreach (DictionaryEntry myDE in SQLStringList)
{
string cmdText = myDE.Key.ToString();
DbParameter[] cmdParms = (DbParameter[])myDE.Value;
PrepareCommand(cmd, conn, trans, cmdText, cmdParms);
int val = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
}
trans.Commit();
}
catch (DbException ex)
{
trans.Rollback();
conn.Close();
conn.Dispose();
throw ex;
}
}
}
}
}
/// <summary>
/// 执行一条计算查询结果语句，返回查询结果（object）,返回首行首列的值;
/// </summary>
/// <param name="SQLString">计算查询结果语句</param>
/// <returns>查询结果（object）</returns>
public object GetSingle(string SQLString, DbParameter[] cmdParms)
{
using (DbConnection connection = provider.CreateConnection())
{
connection.ConnectionString = connectionString;
using (DbCommand cmd = provider.CreateCommand())
{
try
{
PrepareCommand(cmd, connection, null, SQLString, cmdParms);
object obj = cmd.ExecuteScalar();
cmd.Parameters.Clear();
if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
{
return null;
}
else
{
return obj;
}
}
catch (DbException e)
{
connection.Close();
connection.Dispose();
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 DbDataReader ExecuteReader(string SQLString, DbParameter[] cmdParms)
{
DbConnection connection = provider.CreateConnection();
connection.ConnectionString = connectionString;
DbCommand cmd = provider.CreateCommand();
try
{
PrepareCommand(cmd, connection, null, SQLString, cmdParms);
DbDataReader myReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
cmd.Parameters.Clear();
return myReader;
}
catch (DbException e)
{
connection.Close();
connection.Dispose();
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 DataSet GetDataSet(string SQLString, DbParameter[] cmdParms)
{
using (DbConnection connection = provider.CreateConnection())
{
connection.ConnectionString = connectionString;
using (DbCommand cmd = provider.CreateCommand())
{
using (DbDataAdapter da = provider.CreateDataAdapter())
{
PrepareCommand(cmd, connection, null, SQLString, cmdParms);
da.SelectCommand = cmd;
DataSet ds = new DataSet();
try
{
da.Fill(ds, "ds");
cmd.Parameters.Clear();
return ds;
}
catch (DbException ex)
{
connection.Close();
connection.Dispose();
throw new Exception(ex.Message);
}
}
}
}
}
private void PrepareCommand(DbCommand cmd, DbConnection conn, DbTransaction trans, string cmdText, DbParameter[] 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 (DbParameter 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="storeProcName">存储过程名</param>
/// <param name="parameters">所需要的参数</param>
/// <returns>返回受影响的行数</returns>
public int RunProcedureExecuteSql(string storeProcName, DbParameter[] parameters)
{
using (DbConnection connection = provider.CreateConnection())
{
connection.ConnectionString = connectionString;
DbCommand cmd = BuildQueryCommand(connection, storeProcName, parameters);
int rows = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
connection.Close();
return rows;
}
}
/// <summary>
/// 执行存储过程,返回首行首列的值
/// </summary>
/// <param name="storeProcName">存储过程名</param>
/// <param name="parameters">存储过程参数</param>
/// <returns>返回首行首列的值</returns>
public Object RunProcedureGetSingle(string storeProcName, DbParameter[] parameters)
{
using (DbConnection connection = provider.CreateConnection())
{
connection.ConnectionString = connectionString;
try
{
DbCommand cmd = BuildQueryCommand(connection, storeProcName, parameters);
object obj = cmd.ExecuteScalar();
cmd.Parameters.Clear();
if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
{
return null;
}
else
{
return obj;
}
}
catch (DbException e)
{
connection.Close();
connection.Dispose();
throw new Exception(e.Message);
}
}
}
/// <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 DbDataReader RunProcedureGetDataReader(string storedProcName, DbParameter[] parameters)
{
DbConnection connection = provider.CreateConnection();
connection.ConnectionString = connectionString;
DbDataReader returnReader;
DbCommand cmd = BuildQueryCommand(connection, storedProcName, parameters);
cmd.CommandType = CommandType.StoredProcedure;
returnReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
cmd.Parameters.Clear();
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>
/// <returns>DataSet</returns>
public DataSet RunProcedureGetDataSet(string storedProcName, DbParameter[] parameters)
{
using (DbConnection connection = provider.CreateConnection())
{
connection.ConnectionString = connectionString;
DataSet dataSet = new DataSet();
DbDataAdapter sqlDA = provider.CreateDataAdapter();
sqlDA.SelectCommand = BuildQueryCommand(connection, storedProcName, parameters);
sqlDA.Fill(dataSet);
sqlDA.SelectCommand.Parameters.Clear();
sqlDA.Dispose();
return dataSet;
}
}
/// <summary>
/// 执行多个存储过程，实现数据库事务。
/// </summary>
/// <param name="SQLStringList">存储过程的哈希表（value为存储过程语句，key是该语句的DbParameter[]）</param>
public bool RunProcedureTran(Hashtable SQLStringList)
{
using (DbConnection connection = provider.CreateConnection())
{
connection.ConnectionString = connectionString;
connection.Open();
using (DbTransaction trans = connection.BeginTransaction())
{
using (DbCommand cmd = provider.CreateCommand())
{
try
{
//循环
foreach (DictionaryEntry myDE in SQLStringList)
{
cmd.Connection = connection;
string storeName = myDE.Value.ToString();
DbParameter[] cmdParms = (DbParameter[])myDE.Key;
cmd.Transaction = trans;
cmd.CommandText = storeName;
cmd.CommandType = CommandType.StoredProcedure;
if (cmdParms != null)
{
foreach (DbParameter parameter in cmdParms)
{
cmd.Parameters.Add(parameter);
}
}
int val = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
}
trans.Commit();
return true;
}
catch
{
trans.Rollback();
connection.Close();
connection.Dispose();
return false;
}
}
}
}
}
/// <summary>
/// 执行多个存储过程，实现数据库事务。
/// </summary>
/// <param name="SQLStringList">存储过程的哈希表（value为存储过程语句，key是该语句的DbParameter[]）</param>
public bool RunProcedureTran(C_HashTable SQLStringList)
{
using (DbConnection connection = provider.CreateConnection())
{
connection.ConnectionString = connectionString;
connection.Open();
using (DbTransaction trans = connection.BeginTransaction())
{
using (DbCommand cmd = provider.CreateCommand())
{
try
{
//循环
foreach (DbParameter[] cmdParms in SQLStringList.Keys)
{
cmd.Connection = connection;
string storeName = SQLStringList[cmdParms].ToString();
cmd.Transaction = trans;
cmd.CommandText = storeName;
cmd.CommandType = CommandType.StoredProcedure;
if (cmdParms != null)
{
foreach (DbParameter parameter in cmdParms)
{
cmd.Parameters.Add(parameter);
}
}
int val = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
}
trans.Commit();
return true;
}
catch
{
trans.Rollback();
connection.Close();
connection.Dispose();
return false;
}
}
}
}
}
/// <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 DbCommand BuildQueryCommand(DbConnection connection, string storedProcName, DbParameter[] parameters)
{
if (connection.State != ConnectionState.Open)
{
connection.Open();
}
DbCommand command = provider.CreateCommand();
command.CommandText = storedProcName;
command.Connection = connection;
command.CommandType = CommandType.StoredProcedure;
if (parameters != null)
{
foreach (DbParameter parameter in parameters)
{
command.Parameters.Add(parameter);
}
}
return command;
}
#endregion
}
}