(更新时间)2021年5月19日 仓库温控系统(Winform) 08 数据库操作相关帮助类SqlHelper
【摘要】
public class SqlHelper
{
/// <summary>
/// 连接字符串
/// </summary>
private st...
public class SqlHelper
{
/// <summary>
/// 连接字符串
/// </summary>
private static readonly string connStr = ConfigurationManager.ConnectionStrings["connStr"].ConnectionString;
/// <summary>
/// 增、删、改的通用方法
/// 执行Sql语句或存储过程，返回受影响的行数
/// SQL注入
/// </summary>
/// <param name="sql">sql语句或存储过程名</param>
/// <param name="cmdType">执行的脚本类型 1:sql语句 2:存储过程</param>
/// <param name="parameters">参数列表</param>
/// <returns></returns>
public static int ExecuteNonQuery(string sql, int cmdType, params SqlParameter[] parameters)
{
//select @@Identity 返回上一次插入记录时自动产生的ID
int result = 0;//返回结果
using (SqlConnection conn = new SqlConnection(connStr))
{
//执行脚本的对象cmd
SqlCommand cmd = BuilderCommand(conn, sql, cmdType, null, parameters);
result = cmd.ExecuteNonQuery();//执行T-SQL并返回受影响行数
cmd.Parameters.Clear();
}
//using原理：类似于try finally
return result;
}
/// <summary>
/// 执行sql查询，返回第一行第一列的值
/// </summary>
/// <param name="sql">sql语句或存储过程</param>
/// <param name="cmdType">执行的脚本类型 1:sql语句 2:存储过程</param>
/// <param name="parameters">参数列表</param>
/// <returns></returns>
public static object ExecuteScalar(string sql, int cmdType, params SqlParameter[] parameters)
{
object result = null;//返回结果
using (SqlConnection conn = new SqlConnection(connStr))
{
//执行脚本的对象cmd
SqlCommand cmd = BuilderCommand(conn, sql, cmdType, null, parameters);
result = cmd.ExecuteScalar();//执行T-SQL并返回第一行第一列的值
cmd.Parameters.Clear();
if (result == null || result == DBNull.Value)
{
return null;
}
else
{
return result;
}
}
}
/// <summary>
/// 执行sql查询,返回SqlDataReader对象
/// </summary>
/// <param name="sql">sql语句或存储过程</param>
/// <param name="cmdType">执行的脚本类型 1:sql语句 2:存储过程</param>
/// <param name="parameters">参数列表</param>
/// <returns></returns>
public static SqlDataReader ExecuteReader(string sql, int cmdType, params SqlParameter[] parameters)
{
SqlConnection conn = new SqlConnection(connStr);
SqlCommand cmd = BuilderCommand(conn, sql, cmdType, null, parameters);
SqlDataReader reader;
try
{
//conn.Open();连接必须是打开的
reader = cmd.ExecuteReader(CommandBehavior.CloseConnection);//推荐
return reader;
}
catch (Exception ex)
{
conn.Close();
throw new Exception("创建reader对象发生异常", ex);
}
}
/// <summary>
/// 执行查询，查询结果填充到DataTable 只针对查询一个表的情况
/// </summary>
/// <param name="sql">sql语句或存储过程</param>
/// <param name="cmdType">执行的脚本类型 1:sql语句 2:存储过程</param>
/// <param name="parameters">参数列表</param>
/// <returns></returns>
public static DataTable GetDataTable(string sql, int cmdType, params SqlParameter[] parameters)
{
DataTable dt = null;
using (SqlConnection conn = new SqlConnection(connStr))
{
SqlCommand cmd = BuilderCommand(conn, sql, cmdType, null, parameters);
SqlDataAdapter da = new SqlDataAdapter(cmd);
dt = new DataTable();
da.Fill(dt);
cmd.Parameters.Clear();
}
return dt;
}
/// <summary>
/// 执行查询，数据填充到DataSet（多个结果集）
/// </summary>
/// <param name="sql">sql语句或存储过程</param>
/// <param name="cmdType">执行的脚本类型 1:sql语句 2:存储过程</param>
/// <param name="parameters">参数列表</param>
/// <returns></returns>
public static DataSet GetDataSet(string sql, int cmdType, params SqlParameter[] parameters)
{
DataSet ds = null;
using (SqlConnection conn = new SqlConnection(connStr))
{
SqlCommand cmd = BuilderCommand(conn, sql, cmdType, null, parameters);
//数据适配器
//conn 自动打开 断开式连接
SqlDataAdapter da = new SqlDataAdapter(cmd);
ds = new DataSet();
da.Fill(ds);
cmd.Parameters.Clear();
//自动关闭conn
}
return ds;
}
/// <summary>
/// 事务 执行批量sql
/// </summary>
/// <param name="listSql"></param>
/// <returns></returns>
public static bool ExecuteTrans(List<string> listSql)
{
using (SqlConnection conn = new SqlConnection(connStr))
{
conn.Open();//必要条件
SqlTransaction trans = conn.BeginTransaction();//开启事务
SqlCommand cmd = BuilderCommand(conn, "", 1, trans);
try
{
int count = 0;
for (int i = 0; i < listSql.Count; i++)
{
if (listSql[i].Length > 0)
{
cmd.CommandText = listSql[i];
cmd.CommandType = CommandType.Text;
count += cmd.ExecuteNonQuery();//一般执行的是增删改命令
}
}
trans.Commit();//提交
return true;
}
catch (Exception ex)
{
trans.Rollback();//回滚
throw new Exception("执行事务出现异常", ex);
}
}
}
/// <summary>
/// 事务 批量执行 CommandInfo 包括sql,脚本类型，参数列表
/// </summary>
/// <param name="comList"></param>
/// <returns></returns>
public static bool ExecuteTrans(List<CommandInfo> comList)
{
using (SqlConnection conn = new SqlConnection(connStr))
{
conn.Open();
SqlTransaction trans = conn.BeginTransaction();
SqlCommand cmd = BuilderCommand(conn, "", 1, trans);
try
{
int count = 0;
for (int i = 0; i < comList.Count; i++)
{
cmd.CommandText = comList[i].CommandText;
if (comList[i].IsProc)
cmd.CommandType = CommandType.StoredProcedure;
else
cmd.CommandType = CommandType.Text;
if (comList[i].Paras != null && comList[i].Paras.Length > 0)
{
cmd.Parameters.Clear();
foreach (var p in comList[i].Paras)
{
cmd.Parameters.Add(p);
}
}
count += cmd.ExecuteNonQuery();
}
trans.Commit();
return true;
}
catch (Exception ex)
{
trans.Rollback();
throw new Exception("执行事务出现异常", ex);
}
}
}
//public static T ExecuteSql<T>(string sql, int cmdType, DbParameter[] paras, Func<IDbCommand, T> action)
//{
// using (DbConnection conn = new SqlConnection(connStr))
// {
// conn.Open();
// IDbCommand cmd = conn.CreateCommand();
// cmd.CommandText = sql;
// if (cmdType==2)
// cmd.CommandType = CommandType.StoredProcedure;
// return action(cmd);
// }
//}
public static T ExecuteTrans<T>(Func<IDbCommand, T> action)
{
using (IDbConnection conn = new SqlConnection(connStr))
{
conn.Open();
IDbTransaction trans = conn.BeginTransaction();
IDbCommand cmd = conn.CreateCommand();
cmd.Transaction = trans;
return action(cmd);
}
}
/// <summary>
/// 构建SqlCommand
/// </summary>
/// <param name="conn">数据库连接对象</param>
/// <param name="sql">SQL语句或存储过程</param>
/// <param name="comType">命令字符串的类型</param>
/// <param name="trans">事务</param>
/// <param name="paras">参数数组</param>
/// <returns></returns>
private static SqlCommand BuilderCommand(SqlConnection conn, string sql, int cmdType, SqlTransaction trans, params SqlParameter[] paras)
{
if (conn == null) throw new ArgumentNullException("连接对象不能为空！");
SqlCommand command = new SqlCommand(sql, conn);
if (cmdType == 2)
command.CommandType = CommandType.StoredProcedure;
if (conn.State == ConnectionState.Closed)
conn.Open();
if (trans != null)
command.Transaction = trans;
if (paras != null && paras.Length > 0)
{
command.Parameters.Clear();
command.Parameters.AddRange(paras);
}
return command;
}
/// <summary>
/// 添加参数集合
/// </summary>
/// <param name="cmd"></param>
/// <param name="paras"></param>
public static void AddParas(IDbCommand cmd, SqlParameter[] paras)
{
cmd.Parameters.Clear();
if(paras!=null &¶s.Length >0)
{
foreach(SqlParameter p in paras)
{
cmd.Parameters.Add(p);
}
}
}
}
文章来源: codeboy.blog.csdn.net，作者：愚公搬代码，版权归原作者所有，如需转载，请联系作者。
原文链接：codeboy.blog.csdn.net/article/details/117047910
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