【ASP.NET开发】ASP.NET对SQLServer的通用数据库访问类

浏览数：21 / 时间：2015年06月12日

/// <summary>
/// 数据库访问通用类
/// </summary>
public class SqlHelper
{
private string connectionString;
/// <summary>
/// 设定数据库访问字符串
/// </summary>
public string ConnectionString
{
set { connectionString = value; }
}
/// <summary>
/// 构造函数
/// </summary>
/// <param name="connectionString">数据库访问字符串</param>
public SqlHelper(string connectionString)
{
this.connectionString = connectionString;
}
/// <summary>
/// 执行一个查询，并返回查询结果
/// </summary>
/// <param name="sql">要执行的sql语句</param>
/// <param name="commandType">要执行的查询语句的类型，如存储过程或者sql文本命令</param>
/// <returns>返回查询结果集</returns>
public DataTable ExecuteDataTable(string sql,CommandType commandType)
{
return ExecuteDataTable(sql, commandType, null);
}
/// <summary>
/// 执行一个查询，并返回结果集
/// </summary>
/// <param name="sql">要执行的sql文本命令</param>
/// <returns>返回查询的结果集</returns>
public DataTable ExecuteDataTable(string sql)
{
return ExecuteDataTable(sql, CommandType.Text, null);
}
/// <summary>
/// 执行一个查询，并返回查询结果
/// </summary>
/// <param name="sql">要执行的sql语句</param>
/// <param name="commandtype">要执行查询语句的类型，如存储过程或者sql文本命令</param>
/// <param name="parameters">Transact-SQL语句或者存储过程参数数组</param>
/// <returns></returns>
public DataTable ExecuteDataTable(string sql, CommandType commandtype, SqlParameter[] parameters)
{
DataTable data = new DataTable(); //实例化datatable，用于装载查询结果集
using (SqlConnection con = new SqlConnection(connectionString))
{
using (SqlCommand cmd = new SqlCommand(sql, con))
{
cmd.CommandType = commandtype;//设置command的commandType为指定的Commandtype
//如果同时传入了参数，则添加这些参数
if (parameters != null)
{
foreach (SqlParameter parameter in parameters)
{
cmd.Parameters.Add(parameter);
}
}
//通过包含查询sql的sqlcommand实例来实例化sqldataadapter
SqlDataAdapter adapter = new SqlDataAdapter(cmd);
adapter.Fill(data);//填充datatable
}
}
return data;
}
/// <summary>
/// 返回一个SqlDataReader对象的实例
/// </summary>
/// <param name="sql">要执行的SQl查询命令</param>
/// <returns></returns>
public SqlDataReader ExecuteReader(string sql)
{
return ExecuteReader(sql, CommandType.Text, null);
}
/// <summary>
///
/// </summary>
/// <param name="sql">要执行的sql语句</param>
/// <param name="commandType">要执行查询语句的类型，如存储过程或者SQl文本命令</param>
/// <returns></returns>
public SqlDataReader ExecuteReader(string sql,CommandType commandType)
{
return ExecuteReader(sql, commandType, null);
}
/// <summary>
/// 返回一个sqldatareader对象的实例
/// </summary>
/// <param name="sql"></param>
/// <param name="commandType"></param>
/// <param name="parameters"></param>
/// <returns></returns>
public SqlDataReader ExecuteReader(string sql, CommandType commandType, SqlParameter[] parameters)
{
SqlConnection con = new SqlConnection(connectionString);
SqlCommand cmd = new SqlCommand(sql, con);
if (parameters != null)
{
foreach (SqlParameter parameter in parameters)
{
cmd.Parameters.Add(parameters);
}
}
con.Open();
//CommandBehavior.CloseConnection参数指示关闭reader对象时关闭与其关联的Connection对象
return cmd.ExecuteReader(CommandBehavior.CloseConnection);
}
/// <summary>
/// 执行一个查询，返回结果集的首行首列。忽略其他行，其他列
/// </summary>
/// <param name="sql">要执行的SQl命令</param>
/// <returns></returns>
public Object ExecuteScalar(string sql)
{
return ExecuteScalar(sql, CommandType.Text, null);
}
/// <summary>
///
/// </summary>
/// <param name="sql"></param>
/// <param name="commandType"></param>
/// <returns></returns>
public Object ExecuteScalar(string sql, CommandType commandType)
{
return ExecuteScalar(sql, commandType, null);
}
/// <summary>
///
/// </summary>
/// <param name="sql"></param>
/// <param name="commandType">参数类型</param>
/// <param name="parameters"></param>
/// <returns></returns>
public Object ExecuteScalar(string sql,CommandType commandType, SqlParameter[] parameters)
{
Object result=null;
SqlConnection con=new SqlConnection(connectionString);
SqlCommand cmd=new SqlCommand(sql,con);
cmd.CommandType= commandType;
if(parameters!=null)
{
foreach (SqlParameter parapmeter in parameters)
{
cmd.Parameters.Add(parapmeter);
}
}
con.Open();
result=cmd.ExecuteScalar();
con.Close();
return result;
}
/// <summary>
/// 对数据库进行增删改的操作
/// </summary>
/// <param name="sql">要执行的sql命令</param>
/// <returns></returns>
public int ExecuteNonQuery(string sql)
{
return ExecuteNonQuery(sql, CommandType.Text, null);
}
/// <summary>
/// 数据库进行增删改的操作
/// </summary>
/// <param name="sql">对数据库进行操作的sql命令</param>
/// <param name="commandType">要执行查询语句的类型，如存储过程或者sql文本命令</param>
/// <returns></returns>
public int ExecuteNonQuery(string sql, CommandType commandType)
{
return ExecuteNonQuery(sql, commandType, null);
}
/// <summary>
/// 对数据库进行增删改的操作
/// </summary>
/// <param name="sql">要执行的sql语句</param>
/// <param name="commandType">要执行的查询语句类型，如存储过程或者sql文本命令</param>
/// <param name="parameters">Transact-SQL语句或者存储过程的参数数组</param>
/// <returns></returns>
public int ExecuteNonQuery(string sql, CommandType commandType, SqlParameter[] parameters)
{
int count = 0;
SqlConnection con = new SqlConnection(connectionString);
SqlCommand cmd = new SqlCommand(sql, con);
cmd.CommandType = commandType;
if (parameters != null)
{
foreach(SqlParameter parameter in parameters)
{
cmd.Parameters.Add(parameter);
}
}
con.Open();
count = cmd.ExecuteNonQuery();
con.Close();
return count;
}
/// <summary>
/// 返回当前连接的数据库中所有用户创建的数据库
/// </summary>
/// <returns></returns>
public DataTable GetTables()
{
DataTable table = null;
using (SqlConnection con = new SqlConnection(connectionString))
{
con.Open();
table = con.GetSchema("Tables");
}
return table;
}
}
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