第一种方法：
namespace Ambonare.CommService.DAL
{
public class SQLHelper
{
private static readonly string connStr = ConfigurationManager.ConnectionStrings["sql"].ConnectionString;
/// <summary>
/// 非查询语解码器，返回受影响行数
/// </summary>
/// <param name="cmdText"></param>
/// <param name="type"></param>
/// <param name="paras"></param>
/// <returns></returns>
public static int ExecuteNonQuery(string cmdText, CommandType type, params SqlParameter[] paras)
{
using (SqlConnection conn=new SqlConnection(connStr))
{
using (SqlCommand cmd=new SqlCommand(cmdText,conn))
{
if (paras != null)
{
cmd.Parameters.AddRange(paras);
}
cmd.CommandType = type;
conn.Open();
return cmd.ExecuteNonQuery();
}
}
}
/// <summary>
/// 执行查询语句，返回第一行第一列
/// </summary>
/// <param name="cmdText"></param>
/// <param name="paras"></param>
/// <returns></returns>
public static object ExecuteScalar(string cmdText, params SqlParameter[] paras)
{
using (SqlConnection conn=new SqlConnection(connStr))
{
using (SqlCommand cmd=new SqlCommand(cmdText,conn))
{
if (paras != null)
{
cmd.Parameters.AddRange(paras);
}
conn.Open();
return cmd.ExecuteScalar();
}
}
}
/// <summary>
/// 读取数据，执行sqlDateReader
/// </summary>
/// <param name="cmdText"></param>
/// <param name="paras"></param>
/// <returns></returns>
public static SqlDataReader ExecuteReader(string cmdText, params SqlParameter[] paras)
{
SqlConnection conn=new SqlConnection(connStr);
using (SqlCommand cmd=new SqlCommand(cmdText,conn))
{
if (paras != null)
{
cmd.Parameters.AddRange(paras);
}
conn.Open();
try
{
return cmd.ExecuteReader(System.Data.CommandBehavior.CloseConnection);
}
catch (Exception ex)
{
conn.Close();
throw ex;
}
}
}
/// <summary>
/// 返回数据集
/// </summary>
/// <param name="cmdText"></param>
/// <param name="paras"></param>
/// <returns></returns>
public static DataTable DataAdapter(string cmdText, params SqlParameter[] paras)
{
DataTable dt=new DataTable();
using (SqlDataAdapter sda=new SqlDataAdapter(cmdText,connStr))
{
if (paras != null)
{
sda.SelectCommand.Parameters.AddRange(paras);
}
sda.Fill(dt);
}
return dt;
}
}
}
第二种方法<来自动软生成器>:
public abstract class SqlHelper
{
//Database connection strings
public static readonly string ConnectionStringLocalTransaction = ConfigurationManager.AppSettings["SQLConnString1"];
public static readonly string ConnectionStringInventoryDistributedTransaction = ConfigurationManager.AppSettings["SQLConnString2"];
public static readonly string ConnectionStringOrderDistributedTransaction = ConfigurationManager.AppSettings["SQLConnString3"];
public static readonly string ConnectionStringProfile = ConfigurationManager.AppSettings["SQLProfileConnString"];
// Hashtable to store cached parameters
private static Hashtable parmCache = Hashtable.Synchronized(new Hashtable());
/// <summary>
/// Execute a SqlCommand (that returns no resultset) against the database specified in the connection string
/// using the provided parameters.
/// </summary>
/// <remarks>
/// e.g.:
/// int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
/// </remarks>
/// <param name="connectionString">a valid connection string for a SqlConnection</param>
/// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
/// <param name="commandText">the stored procedure name or T-SQL command</param>
/// <param name="commandParameters">an array of SqlParamters used to execute the command</param>
/// <returns>an int representing the number of rows affected by the command</returns>
public static int ExecuteNonQuery(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
{
SqlCommand cmd = new SqlCommand();
using (SqlConnection conn = new SqlConnection(connectionString))
{
PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
int val = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
return val;
}
}
/// <summary>
/// Execute a SqlCommand (that returns no resultset) against an existing database connection
/// using the provided parameters.
/// </summary>
/// <remarks>
/// e.g.:
/// int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
/// </remarks>
/// <param name="conn">an existing database connection</param>
/// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
/// <param name="commandText">the stored procedure name or T-SQL command</param>
/// <param name="commandParameters">an array of SqlParamters used to execute the command</param>
/// <returns>an int representing the number of rows affected by the command</returns>
public static int ExecuteNonQuery(SqlConnection connection, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
{
SqlCommand cmd = new SqlCommand();
PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
int val = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
return val;
}
/// <summary>
/// Execute a SqlCommand (that returns no resultset) using an existing SQL Transaction
/// using the provided parameters.
/// </summary>
/// <remarks>
/// e.g.:
/// int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
/// </remarks>
/// <param name="trans">an existing sql transaction</param>
/// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
/// <param name="commandText">the stored procedure name or T-SQL command</param>
/// <param name="commandParameters">an array of SqlParamters used to execute the command</param>
/// <returns>an int representing the number of rows affected by the command</returns>
public static int ExecuteNonQuery(SqlTransaction trans, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
{
SqlCommand cmd = new SqlCommand();
PrepareCommand(cmd, trans.Connection, trans, cmdType, cmdText, commandParameters);
int val = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
return val;
}
/// <summary>
/// Execute a SqlCommand that returns a resultset against the database specified in the connection string
/// using the provided parameters.
/// </summary>
/// <remarks>
/// e.g.:
/// SqlDataReader r = ExecuteReader(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
/// </remarks>
/// <param name="connectionString">a valid connection string for a SqlConnection</param>
/// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
/// <param name="commandText">the stored procedure name or T-SQL command</param>
/// <param name="commandParameters">an array of SqlParamters used to execute the command</param>
/// <returns>A SqlDataReader containing the results</returns>
public static SqlDataReader ExecuteReader(string connectionString, CommandType cmdType, string cmdText, params 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;
}
}
/// <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">a valid connection string for a SqlConnection</param>
/// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
/// <param name="commandText">the stored procedure name or T-SQL command</param>
/// <param name="commandParameters">an array of SqlParamters used to execute the command</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, params 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="conn">an existing database connection</param>
/// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
/// <param name="commandText">the stored procedure name or T-SQL command</param>
/// <param name="commandParameters">an array of SqlParamters used to execute the command</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, params SqlParameter[] commandParameters)
{
SqlCommand cmd = new SqlCommand();
PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
object val = cmd.ExecuteScalar();
cmd.Parameters.Clear();
return val;
}
/// <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, params 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>
/// Prepare a command for execution
/// </summary>
/// <param name="cmd">SqlCommand object</param>
/// <param name="conn">SqlConnection object</param>
/// <param name="trans">SqlTransaction object</param>
/// <param name="cmdType">Cmd type e.g. stored procedure or text</param>
/// <param name="cmdText">Command text, e.g. Select * from Products</param>
/// <param name="cmdParms">SqlParameters to use in the command</param>
private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, CommandType cmdType, string cmdText, SqlParameter[] cmdParms)
{
if (conn.State != ConnectionState.Open)
conn.Open();
cmd.Connection = conn;
cmd.CommandText = cmdText;
if (trans != null)
cmd.Transaction = trans;
cmd.CommandType = cmdType;
if (cmdParms != null)
{
foreach (SqlParameter parm in cmdParms)
cmd.Parameters.Add(parm);
}
}
}
第三种方法 微软自带的：
