C# DBHelper类学习笔记(一)
借鉴了一下大佬的DBHelper类,自己又捣鼓了一下.
using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;
namespace DB
{
public class DBHP
{
//app.config 连接字段
private static readonly string _connectionString = ConfigurationManager.ConnectionStrings["ConnStr"].ConnectionString;
//定义SQL连接对象
private static SqlConnection _conn = null;
private DBHP() { }
#region 获取数据库连接对象
private static SqlConnection GetSqlConnection()
{
if (_conn == null || _conn.ConnectionString == "")
{
_conn = new SqlConnection(_connectionString);
}
return _conn;
}
#endregion
#region 打开数据库连接
private static void OpenSQLConnection()
{
if (_conn.State == ConnectionState.Closed)
{
_conn.Open();
}
else
{
_conn.Close();
_conn.Open();
}
}
#endregion
#region 关闭数据库连接
private static void CloseSQLConnection()
{
if (_conn.State == ConnectionState.Open)
{
_conn.Close();
}
}
#endregion
#region 重载=>执行非查询单个数据库语句(增加,删除,修改)
public static int ExecuteNonQuery_Single(string sqlStr)
{
return ExecuteSql_NonQuery(sqlStr, null, CommandType.Text);
}
public static int ExecuteNonQuery_Single(string sqlStr, SqlParameter[] pars)
{
return ExecuteSql_NonQuery(sqlStr, pars, CommandType.Text);
}
public static int ExecuteNonQuery_Proc(string procName)
{
return ExecuteSql_NonQuery(procName, null, CommandType.StoredProcedure);
}
public static int ExecuteNonQuery_Proc(string procName, SqlParameter[] pars)
{
return ExecuteSql_NonQuery(procName, pars, CommandType.StoredProcedure);
}
public static int ExecuteNonQuery_ArrayList(ArrayList sqlStrArray)
{
int sqlResult = 0;
foreach (string str in sqlStrArray)
{
if (ExecuteSql_NonQuery(str, null, CommandType.Text) > 0)
{
sqlResult++;
}
}
return sqlResult;
}
public static int ExecuteNonQuery_ArrayList(ArrayList sqlStrArray, SqlParameter[] pars)
{
int sqlResult = 0;
foreach (string str in sqlStrArray)
{
if (ExecuteSql_NonQuery(str, pars, CommandType.Text) > 0)
{
sqlResult++;
}
}
return sqlResult;
}
#endregion
#region 执行非查询单个数据库语句(增加,删除,修改)
private static int ExecuteSql_NonQuery(string sqlStr, SqlParameter[] paras, CommandType type)
{
int SqlResult = 0;
//创建数据库连接对象.
using (SqlConnection _con = GetSqlConnection())
{
//创建操作对象.
SqlCommand comd = _con.CreateCommand();
//定义操作类型.
comd.CommandType = type;
//定义操作语句.
comd.CommandText = sqlStr;
//定义执行语句参数.
if (paras != null)
{
comd.Parameters.AddRange(paras);
}
//打开数据库连接.
OpenSQLConnection();
//执行操作.
SqlResult = comd.ExecuteNonQuery();
//关闭数据库连接,释放操作对象.
//comd.Dispose();
CloseSQLConnection();
}
//返回操作结果.
return SqlResult;
}
#endregion
#region 重载=>执行查询数据库语句,返回首行首列字段值.
public static object ExecuteScalar_object(string strSQL)
{
return ExecuteSql_Scalar(strSQL, null, CommandType.Text);
}
public static object ExecuteScalar_object(string strSQL, SqlParameter[] pars)
{
return ExecuteSql_Scalar(strSQL, pars, CommandType.Text);
}
public static int ExecuteScalar_ToInt32(string strSQL)
{
object a = null;
a = ExecuteSql_Scalar(strSQL, null, CommandType.Text);
if (a.Equals(DBNull.Value))
{
a = -1 ;
}
return Convert.ToInt32(a);
}
public static int ExecuteScalar_ToInt32(string strSQL, SqlParameter[] pars)
{
object a = null;
a = ExecuteSql_Scalar(strSQL, pars, CommandType.Text);
if (a.Equals(DBNull.Value))
{
a = -1;
}
return Convert.ToInt32(a);
}
#endregion
#region 执行查询数据库语句,返回首行首列字段值.
private static object ExecuteSql_Scalar(string strSQL, SqlParameter[] paras, CommandType cmdtype)
{
object SqlResult = null;
//创建数据库连接对象.
using (SqlConnection _con = GetSqlConnection())
{
//创建操作对象.
SqlCommand comd = _con.CreateCommand();
//定义操作类型.
comd.CommandType = cmdtype;
//定义操作语句.
comd.CommandText = strSQL;
//定义执行语句参数.
if (paras != null)
{
comd.Parameters.AddRange(paras);
}
//打开数据库连接.
OpenSQLConnection();
//执行操作.
SqlResult = comd.ExecuteScalar();
//关闭数据库连接,释放操作对象.
comd.Dispose();
CloseSQLConnection();
}
//返回操作结果.
return SqlResult;
}
#endregion
#region 批量插入数据(TableMode)
///
/// 往数据库中批量插入数据
///
/// 数据源表
/// 服务器上目标表
public static void BulkToDB(DataTable sourceDt, string targetTable)
{
SqlConnection conn = GetSqlConnection();
SqlBulkCopy bulkCopy = new SqlBulkCopy(conn); //用其它源的数据有效批量加载sql server表中
bulkCopy.DestinationTableName = targetTable; //服务器上目标表的名称
bulkCopy.BatchSize = sourceDt.Rows.Count; //每一批次中的行数
try
{
conn.Open();
if (sourceDt != null && sourceDt.Rows.Count != 0)
bulkCopy.WriteToServer(sourceDt); //将提供的数据源中的所有行复制到目标表中
}
catch (Exception ex)
{
throw ex;
}
finally
{
conn.Close();
if (bulkCopy != null)
bulkCopy.Close();
}
}
#endregion
#region 执行查询，返回DataSet对象
public static DataSet GetDataSet(string strSQL)
{
return GetDataSet(strSQL, null, CommandType.Text);
}
public static DataSet GetDataSet(string strSQL, SqlParameter[] pas)
{
return GetDataSet(strSQL, pas, CommandType.Text);
}
///
/// 执行查询，返回DataSet对象
///
/// sql语句
/// 参数数组
/// Command类型
/// DataSet对象
private static DataSet GetDataSet(string strSQL, SqlParameter[] pas, CommandType cmdtype)
{
DataSet dt = new DataSet(); ;
using (SqlConnection conn = GetSqlConnection())
{
SqlDataAdapter da = new SqlDataAdapter(strSQL, conn);
da.SelectCommand.CommandType = cmdtype;
if (pas != null)
{
da.SelectCommand.Parameters.AddRange(pas);
}
da.Fill(dt);
}
return dt;
}
#endregion
#region 执行查询，返回DataTable对象
public static DataTable GetDataTable(string strSQL)
{
return GetDataTable(strSQL, null, CommandType.Text);
}
public static DataTable GetDataTable(string strSQL, SqlParameter[] pas)
{
return GetDataTable(strSQL, pas, CommandType.Text);
}
///
/// 执行查询，返回DataTable对象
///
/// sql语句
/// 参数数组
/// Command类型
/// DataTable对象
private static DataTable GetDataTable(string strSQL, SqlParameter[] pas, CommandType cmdtype)
{
DataTable dt = new DataTable(); ;
using (SqlConnection conn = GetSqlConnection())
{
SqlDataAdapter da = new SqlDataAdapter(strSQL, conn);
da.SelectCommand.CommandType = cmdtype;
if (pas != null)
{
da.SelectCommand.Parameters.AddRange(pas);
}
da.Fill(dt);
}
return dt;
}
#endregion
///
/// 精确查询某数据是否存在,SQL语句写到操作符为止
///
/// 查询的SQL语句
/// 查询条件参数
/// 是否存在
private static bool ObjectIsExists(string sqlStr, object pra)
{
bool _isExists;
if (ExecuteScalar_object(sqlStr + "'" + pra.ToString() + "'") != null)
{
_isExists = true;
}
else
{
_isExists = false;
}
return _isExists;
}
}
}