这篇文章给大家分享的是有关C#如何实现SQL封装的内容。小编觉得挺实用的，因此分享给大家做个参考，一起跟随小编过来看看吧。
SQLHelper.as , 代码如下：
using System;
using System.Collections;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using System.Web;
namespace DBDome
{
/// 此类为抽象类，
/// 不允许实例化，在应用时直接调用即可
/// </summary>
public sealed class SqlHelper
{
private SqlHelper() { }
/// <summary>
/// 数据库连接字符串
/// </summary>
public static readonly string connectionString = ConfigurationManager.ConnectionStrings["con"].ToString();
// Hashtable to store cached parameters
private static Hashtable parmCache = Hashtable.Synchronized(new Hashtable());
#region//ExecteNonQuery方法
/// <summary>
///执行一个不需要返回值的SqlCommand命令，通过指定专用的连接字符串。
/// 使用参数数组形式提供参数列表
/// </summary>
/// <param name="connectionString">一个有效的数据库连接字符串</param>
/// <param name="cmdType">SqlCommand命令类型 (存储过程， T-SQL语句， 等等。)</param>
/// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param>
/// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
/// <returns>返回一个数值表示此SqlCommand命令执行后影响的行数</returns>
public static int ExecteNonQuery(string connectionString, CommandType cmdType, string cmdText, SqlParameter[] commandParameters)
{
SqlCommand cmd = new SqlCommand();
using (SqlConnection conn = new SqlConnection(connectionString))
{
//通过PrePareCommand方法将参数逐个加入到SqlCommand的参数集合中
PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
int val = cmd.ExecuteNonQuery();
//清空SqlCommand中的参数列表
cmd.Parameters.Clear();
return val;
}
}
/// <summary>
///执行一个不需要返回值的SqlCommand命令，通过指定专用的连接字符串。
/// 使用参数数组形式提供参数列表
/// </summary>
/// <param name="cmdType">SqlCommand命令类型 (存储过程， T-SQL语句， 等等。)</param>
/// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param>
/// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
/// <returns>返回一个数值表示此SqlCommand命令执行后影响的行数</returns>
public static int ExecteNonQuery(CommandType cmdType, string cmdText, SqlParameter[] commandParameters)
{
return ExecteNonQuery(connectionString, cmdType, cmdText, commandParameters);
}
/// <summary>
///存储过程专用
/// </summary>
/// <param name="cmdText">存储过程的名字</param>
/// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
/// <returns>返回一个数值表示此SqlCommand命令执行后影响的行数</returns>
public static int ExecteNonQueryProducts(string cmdText, SqlParameter[] commandParameters)
{
return ExecteNonQuery(CommandType.StoredProcedure, cmdText, commandParameters);
}
/// <summary>
///Sql语句专用
/// </summary>
/// <param name="cmdText">T_Sql语句</param>
/// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
/// <returns>返回一个数值表示此SqlCommand命令执行后影响的行数</returns>
public static int ExecteNonQueryText(string cmdText, SqlParameter[] commandParameters)
{
return ExecteNonQuery(CommandType.Text, cmdText, commandParameters);
}
#endregion
#region//GetTable方法
/// <summary>
/// 执行一条返回结果集的SqlCommand，通过一个已经存在的数据库连接
/// 使用参数数组提供参数
/// </summary>
/// <param name="connecttionString">一个现有的数据库连接</param>
/// <param name="cmdTye">SqlCommand命令类型</param>
/// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param>
/// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
/// <returns>返回一个表集合(DataTableCollection)表示查询得到的数据集</returns>
public static DataTableCollection GetTable(string connecttionString, CommandType cmdTye, string cmdText, SqlParameter[] commandParameters)
{
SqlCommand cmd = new SqlCommand();
DataSet ds = new DataSet();
using (SqlConnection conn = new SqlConnection(connecttionString))
{
PrepareCommand(cmd, conn, null, cmdTye, cmdText, commandParameters);
SqlDataAdapter adapter = new SqlDataAdapter();
adapter.SelectCommand = cmd;
adapter.Fill(ds);
}
DataTableCollection table = ds.Tables;
return table;
}
/// <summary>
/// 执行一条返回结果集的SqlCommand，通过一个已经存在的数据库连接
/// 使用参数数组提供参数
/// </summary>
/// <param name="cmdTye">SqlCommand命令类型</param>
/// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param>
/// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
/// <returns>返回一个表集合(DataTableCollection)表示查询得到的数据集</returns>
public static DataTableCollection GetTable(CommandType cmdTye, string cmdText, SqlParameter[] commandParameters)
{
return GetTable(cmdTye, cmdText, commandParameters);
}
/// <summary>
/// 存储过程专用
/// </summary>
/// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param>
/// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
/// <returns>返回一个表集合(DataTableCollection)表示查询得到的数据集</returns>
public static DataTableCollection GetTableProducts(string cmdText, SqlParameter[] commandParameters)
{
return GetTable(CommandType.StoredProcedure, cmdText, commandParameters);
}
/// <summary>
/// Sql语句专用
/// </summary>
/// <param name="cmdText"> T-SQL 语句</param>
/// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
/// <returns>返回一个表集合(DataTableCollection)表示查询得到的数据集</returns>
public static DataTableCollection GetTableText(string cmdText, SqlParameter[] commandParameters)
{
return GetTable(CommandType.Text, cmdText, commandParameters);
}
#endregion
/// <summary>
/// 为执行命令准备参数
/// </summary>
/// <param name="cmd">SqlCommand 命令</param>
/// <param name="conn">已经存在的数据库连接</param>
/// <param name="trans">数据库事物处理</param>
/// <param name="cmdType">SqlCommand命令类型 (存储过程， T-SQL语句， 等等。)</param>
/// <param name="cmdText">Command text，T-SQL语句 例如 Select * from Products</param>
/// <param name="cmdParms">返回带参数的命令</param>
private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, CommandType cmdType, string cmdText, SqlParameter[] cmdParms)
{
//判断数据库连接状态
if (conn.State != ConnectionState.Open)
conn.Open();
cmd.Connection = conn;
cmd.CommandText = cmdText;
//判断是否需要事物处理
if (trans != null)
cmd.Transaction = trans;
cmd.CommandType = cmdType;
if (cmdParms != null)
{
foreach (SqlParameter parm in cmdParms)
cmd.Parameters.Add(parm);
}
}
/// <summary>
/// Execute a SqlCommand that returns a resultset against the database specified in the connection string
/// using the provided parameters.
/// </summary>
/// <param name="connectionString">一个有效的数据库连接字符串</param>
/// <param name="cmdType">SqlCommand命令类型 (存储过程， T-SQL语句， 等等。)</param>
/// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param>
/// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
/// <returns>A SqlDataReader containing the results</returns>
public static SqlDataReader ExecuteReader(string connectionString, CommandType cmdType, string cmdText, SqlParameter[] commandParameters)
{
SqlCommand cmd = new SqlCommand();
SqlConnection conn = new SqlConnection(connectionString);
// we use a try/catch here because if the method throws an exception we want to
// close the connection throw code, because no datareader will exist, hence the
// commandBehaviour.CloseConnection will not work
try
{
PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
SqlDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
cmd.Parameters.Clear();
return rdr;
}
catch
{
conn.Close();
throw;
}
}
#region//ExecuteDataSet方法
/// <summary>
/// return a dataset
/// </summary>
/// <param name="connectionString">一个有效的数据库连接字符串</param>
/// <param name="cmdType">SqlCommand命令类型 (存储过程， T-SQL语句， 等等。)</param>
/// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param>
/// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
/// <returns>return a dataset</returns>
public static DataSet ExecuteDataSet(string connectionString, CommandType cmdType, string cmdText, SqlParameter[] commandParameters)
{
SqlConnection conn = new SqlConnection(connectionString);
SqlCommand cmd = new SqlCommand();
try
{
PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
SqlDataAdapter da = new SqlDataAdapter();
DataSet ds = new DataSet();
da.SelectCommand = cmd;
da.Fill(ds);
return ds;
}
catch
{
conn.Close();
throw;
}
}
/// <summary>
/// 返回一个DataSet
/// </summary>
/// <param name="cmdType">SqlCommand命令类型 (存储过程， T-SQL语句， 等等。)</param>
/// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param>
/// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
/// <returns>return a dataset</returns>
public static DataSet ExecuteDataSet(CommandType cmdType, string cmdText, SqlParameter[] commandParameters)
{
return ExecuteDataSet(connectionString, cmdType, cmdText, commandParameters);
}
/// <summary>
/// 返回一个DataSet
/// </summary>
/// <param name="cmdText">存储过程的名字</param>
/// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
/// <returns>return a dataset</returns>
public static DataSet ExecuteDataSetProducts(string cmdText, SqlParameter[] commandParameters)
{
return ExecuteDataSet(connectionString, CommandType.StoredProcedure, cmdText, commandParameters);
}
/// <summary>
/// 返回一个DataSet
/// </summary>
/// <param name="cmdText">T-SQL 语句</param>
/// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
/// <returns>return a dataset</returns>
public static DataSet ExecuteDataSetText(string cmdText, SqlParameter[] commandParameters)
{
return ExecuteDataSet(connectionString, CommandType.Text, cmdText, commandParameters);
}
public static DataView ExecuteDataSet(string connectionString, string sortExpression, string direction, CommandType cmdType, string cmdText, SqlParameter[] commandParameters)
{
SqlConnection conn = new SqlConnection(connectionString);
SqlCommand cmd = new SqlCommand();
try
{
PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
SqlDataAdapter da = new SqlDataAdapter();
DataSet ds = new DataSet();
da.SelectCommand = cmd;
da.Fill(ds);
DataView dv = ds.Tables[0].DefaultView;
dv.Sort = sortExpression + " " + direction;
return dv;
}
catch
{
conn.Close();
throw;
}
}
#endregion
#region // ExecuteScalar方法
/// <summary>
/// 返回第一行的第一列
/// </summary>
/// <param name="cmdType">SqlCommand命令类型 (存储过程， T-SQL语句， 等等。)</param>
/// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param>
/// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
/// <returns>返回一个对象</returns>
public static object ExecuteScalar(CommandType cmdType, string cmdText, SqlParameter[] commandParameters)
{
return ExecuteScalar(SqlHelper.connectionString, cmdType, cmdText, commandParameters);
}
/// <summary>
/// 返回第一行的第一列存储过程专用
/// </summary>
/// <param name="cmdText">存储过程的名字</param>
/// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
/// <returns>返回一个对象</returns>
public static object ExecuteScalarProducts(string cmdText, SqlParameter[] commandParameters)
{
return ExecuteScalar(SqlHelper.connectionString, CommandType.StoredProcedure, cmdText, commandParameters);
}
/// <summary>
/// 返回第一行的第一列Sql语句专用
/// </summary>
/// <param name="cmdText">者 T-SQL 语句</param>
/// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
/// <returns>返回一个对象</returns>
public static object ExecuteScalarText(string cmdText, SqlParameter[] commandParameters)
{
return ExecuteScalar(SqlHelper.connectionString, CommandType.Text, cmdText, commandParameters);
}
/// <summary>
/// Execute a SqlCommand that returns the first column of the first record against the database specified in the connection string
/// using the provided parameters.
/// </summary>
/// <remarks>
/// e.g.:
/// Object obj = ExecuteScalar(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
/// </remarks>
/// <param name="connectionString">一个有效的数据库连接字符串</param>
/// <param name="cmdType">SqlCommand命令类型 (存储过程， T-SQL语句， 等等。)</param>
/// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param>
/// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
/// <returns>An object that should be converted to the expected type using Convert.To{Type}</returns>
public static object ExecuteScalar(string connectionString, CommandType cmdType, string cmdText, SqlParameter[] commandParameters)
{
SqlCommand cmd = new SqlCommand();
using (SqlConnection connection = new SqlConnection(connectionString))
{
PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
object val = cmd.ExecuteScalar();
cmd.Parameters.Clear();
return val;
}
}
/// <summary>
/// Execute a SqlCommand that returns the first column of the first record against an existing database connection
/// using the provided parameters.
/// </summary>
/// <remarks>
/// e.g.:
/// Object obj = ExecuteScalar(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
/// </remarks>
/// <param name="connectionString">一个有效的数据库连接字符串</param>
/// <param name="cmdType">SqlCommand命令类型 (存储过程， T-SQL语句， 等等。)</param>
/// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param>
/// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
/// <returns>An object that should be converted to the expected type using Convert.To{Type}</returns>
public static object ExecuteScalar(SqlConnection connection, CommandType cmdType, string cmdText, SqlParameter[] commandParameters)
{
SqlCommand cmd = new SqlCommand();
PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
object val = cmd.ExecuteScalar();
cmd.Parameters.Clear();
return val;
}
#endregion
/// <summary>
/// add parameter array to the cache
/// </summary>
/// <param name="cacheKey">Key to the parameter cache</param>
/// <param name="cmdParms">an array of SqlParamters to be cached</param>
public static void CacheParameters(string cacheKey, SqlParameter[] commandParameters)
{
parmCache[cacheKey] = commandParameters;
}
/// <summary>
/// Retrieve cached parameters
/// </summary>
/// <param name="cacheKey">key used to lookup parameters</param>
/// <returns>Cached SqlParamters array</returns>
public static SqlParameter[] GetCachedParameters(string cacheKey)
{
SqlParameter[] cachedParms = (SqlParameter[])parmCache[cacheKey];
if (cachedParms == null)
return null;
SqlParameter[] clonedParms = new SqlParameter[cachedParms.Length];
for (int i = 0, j = cachedParms.Length; i < j; i++)
clonedParms[i] = (SqlParameter)((ICloneable)cachedParms[i]).Clone();
return clonedParms;
}
/// <summary>
/// 检查是否存在
/// </summary>
/// <param name="strSql">Sql语句</param>
/// <returns>bool结果</returns>
public static bool Exists(string strSql)
{
int cmdresult = Convert.ToInt32(ExecuteScalar(connectionString, CommandType.Text, strSql, null));
if (cmdresult == 0)
{
return false;
}
else
{
return true;
}
}
/// <summary>
/// 检查是否存在
/// </summary>
/// <param name="strSql">Sql语句</param>
/// <param name="cmdParms">参数</param>
/// <returns>bool结果</returns>
public static bool Exists(string strSql, SqlParameter[] cmdParms)
{
int cmdresult = Convert.ToInt32(ExecuteScalar(connectionString, CommandType.Text, strSql, cmdParms));
if (cmdresult == 0)
{
return false;
}
else
{
return true;
}
}
}
}本篇博客只涉及到添加数据 （insert into） 并陆续的更新其他SQL操作， 本人希望封装一个全套基本的SQL操作。在以后如果从事后端可以在此扩展 ， 不喜勿喷。
本人希望用SqlParameter的方式来构建T-SQL
一 ： 构建基本的T-SQL（ 没有SqlParameter参数注入 ）
using DBDome.model;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;
namespace DBDome.com
{
/// <summary>
/// SQL构建器(还没与赋值)
/// </summary>
public sealed class SQL_Structure
{
private SQL_Structure() { }
/// <summary>
/// 添加一个数据的T-SQL的构成
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="model"></param>
/// <returns></returns>
public static string ADD_T_SQL<T>( T model ) where T : BaseModel
{
string base_add = @"insert into [{0}] ({1}) values ({2})";//表名 ， 列明 ， 对应的值
Type model_type = model.GetType();
string[] arr = model_type.Name.Split(new char[] { '.' });
string table_name = arr[arr.Length - 1];//获得表的名称
PropertyInfo[] p_intos = model_type.GetProperties();
StringBuilder table_field_name = new StringBuilder();
StringBuilder table_field_value = new StringBuilder();
PropertyInfo item = null;
for (int i = 0; i < p_intos.Length; i++)
{
item = p_intos[i];
if (item.Name != "id")//不应添加主键
{
table_field_name.Append(item.Name + ",");
table_field_value.Append("@" + item.Name + ",");
}
}
return String.Format(base_add, table_name, table_field_name.ToString().Substring(0, table_field_name.ToString().Length-1), table_field_value.ToString().Substring(0,table_field_value.ToString().Length-1));
}
}
}二 ： 好了我现在构造与SQL表映射的模型类
①，所有model的基类：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace DBDome.model
{
public abstract class BaseModel
{
protected int _id;
/// <summary>
/// 主键ID号
/// </summary>
public virtual int id
{
get { return this._id; }
set { this._id = value; }
}
}
}② ， 继承model的一个类User也是我的一个SQL表名
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace DBDome.model
{
public sealed class User : BaseModel
{
public string name { get; set; }
public short sex{ get; set; }
public int lv{ get; set; }
public string username{ get; set; }
public string userpwd{ get; set; }
}
}三 ， 我们添加一条数据 ， 需要构建参数 SqlParameter[]
using DBDome.model;
using System;
using System.Collections.Generic;
using System.Data.SqlClient;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Data;
namespace DBDome.com
{
/// <summary>
/// SqlParameter 构建
/// </summary>
public sealed class SqlParameter_Structure
{
private SqlParameter_Structure() { }
/// <summary>
/// 构建T-SQL参数 ADD
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="model"></param>
/// <returns></returns>
public static SqlParameter[] ADD_T_SQL<T>(T model) where T : BaseModel
{
Type model_type = model.GetType();
PropertyInfo[] p_intos = model_type.GetProperties();
SqlParameter[] sql_param = new SqlParameter[p_intos.Length - 1];//不需要主键
PropertyInfo item = null;
string p_name = "";
SqlParameter cell = null;
int j = 0;
for (int i = 0; i < p_intos.Length; i++)
{
item = p_intos[i];
p_name = item.Name;
if (p_name == "id") continue;
// Console.WriteLine("字段 {0} 的类型为 {1} ", p_name ,item.PropertyType);
cell = new SqlParameter(p_name, SqlParameter_Structure.Get_SqlDbType_SqlType(item.PropertyType));
cell.Value = item.GetValue(model, null);
sql_param[j] = cell;
j++;
}
return sql_param;
}
private static SqlDbType Get_SqlDbType_SqlType(Type cshaper)
{
string[] arr = cshaper.ToString().Split(new char[] { '.' });
string toLow = arr[arr.Length - 1].ToLower();
switch (toLow)
{
case "string":
return SqlDbType.NVarChar;
break;
case "int16":
return SqlDbType.Bit;
break;
case "int32":
return SqlDbType.Int;
break;
default:
throw new Exception(String.Format("T-SQL参数没有配对的类型 {0}" ,cshaper));
break;
}
}
}
}感谢各位的阅读！关于“C#如何实现SQL封装”这篇文章就分享到这里了，希望以上内容可以对大家有一定的帮助，让大家可以学到更多知识，如果觉得文章不错，可以把它分享出去让更多的人看到吧！
