每次新项目的时候,都要从头去找一遍数据库工具类。这里分享一个简单实用的C#的通用DbHelper工具类,支持数据连接池。
<connectionStrings> <add name="dh_web" connectionString="Data Source=xxx.com;Initial Catalog=xx_db;User ID=xx;Password=**; pooling=true;max pool size=200" providerName="System.Data.SqlClient"/></connectionStrings>
public class DBHelper
{
private static string connectionString = ConfigurationManager.ConnectionStrings["dh_web"].ConnectionString;
//不带参数的执行命令
public static int ExecuteCommand(string safeSql)
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();
SqlCommand cmd = new SqlCommand(safeSql, connection);
return cmd.ExecuteNonQuery();
}
}
//带参数的执行命令
public static int ExecuteCommand(string sql, params SqlParameter[] values)
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();
SqlCommand cmd = new SqlCommand(sql, connection);
cmd.Parameters.AddRange(values);
return cmd.ExecuteNonQuery();
}
}
public static int GetScalar(string safeSql)
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();
SqlCommand cmd = new SqlCommand(safeSql, connection);
return Convert.ToInt32(cmd.ExecuteScalar());
}
}
public static int GetScalar(string sql, params SqlParameter[] values)
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();
SqlCommand cmd = new SqlCommand(sql, connection);
cmd.Parameters.AddRange(values);
return Convert.ToInt32(cmd.ExecuteScalar());
}
}
public static SqlDataReader GetReader(string safeSql)
{
SqlConnection connection = new SqlConnection(connectionString);
connection.Open();
SqlCommand cmd = new SqlCommand(safeSql, connection);
return cmd.ExecuteReader(CommandBehavior.CloseConnection);
}
public static SqlDataReader GetReader(string sql, params SqlParameter[] values)
{
SqlConnection connection = new SqlConnection(connectionString);
connection.Open();
SqlCommand cmd = new SqlCommand(sql, connection);
cmd.Parameters.AddRange(values);
return cmd.ExecuteReader(CommandBehavior.CloseConnection);
}
public static DataTable GetDataSet(string safeSql)
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
DataSet ds = new DataSet();
SqlCommand cmd = new SqlCommand(safeSql, connection);
SqlDataAdapter da = new SqlDataAdapter(cmd);
da.Fill(ds);
return ds.Tables[0];
}
}
public static DataTable GetDataSet(string sql, params SqlParameter[] values)
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
DataSet ds = new DataSet();
SqlCommand cmd = new SqlCommand(sql, connection);
cmd.Parameters.AddRange(values);
SqlDataAdapter da = new SqlDataAdapter(cmd);
da.Fill(ds);
return ds.Tables[0];
}
}
}
注意:CommandBehavior.CloseConnection解决了流读取数据模式下,数据库连接不能有效关闭的情况.当某个XXXDataReader对象在生成时使用了CommandBehavior.CloseConnection,那数据库连接将在XXXDataReader对象关闭时自动关闭.