- /// <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;
- }
- }
- 本文出自 “强子的专栏” 博客,请务必保留此出处http://yisuowushinian.blog.51cto.com/4241271/999324
时间: 2024-10-05 20:37:13