.Net(C#)数据库访问连接方式

一、MySql

static string  strConn = "server=.;database=mast;uid=sa;pwd=123456;integrated Security=SSPI;persist Security info=false;";

 /// <summary>
 /// 执行SQL语句，返回影响的记录数
 /// </summary>
 /// <param name="SQLString">SQL语句</param>
 /// <returns>影响的记录数</returns>

public static int MyExecuteSql(string SQLString)
        {
            using (MySqlConnection connection = new MySqlConnection(strConn))
            {
                using (MySqlCommand cmd = new MySqlCommand(SQLString, connection))
                {
                    try
                    {
                        connection.Open();
                        int rows = cmd.ExecuteNonQuery();
                        return rows;
                    }
                    catch (System.Data.SqlClient.SqlException e)
                    {
                        connection.Close();
                        throw e;
                    }
                }
            }
        }

        /// <summary>
        /// 执行查询语句，返回DataTable
        /// </summary>
        /// <param name="SQLString">查询语句</param>
        /// <returns>DataSet</returns>
        public static DataTable MyQuery(string SQLString)
        {
            using (MySqlConnection connection = new MySqlConnection(strConn))
            {
                DataSet ds = new DataSet();
                try
                {
                    connection.Open();
                    MySqlDataAdapter command = new MySqlDataAdapter(SQLString, connection);
                    command.Fill(ds, "ds");
                }
                catch (System.Data.SqlClient.SqlException ex)
                {
                    throw new Exception(ex.Message);
                }
                return ds.Tables[0];
            }
        }

二、SQLServer

static string strConn = "Data Source=.;database=mast;User id=root;Password=123456;pooling=false;CharSet=utf8;port=3306;";

        /// <summary>
        /// 执行SQL语句，返回影响的记录数
        /// </summary>
        /// <param name="SQLString">SQL语句</param>
        /// <returns>影响的记录数</returns>
        public static int ExecuteSql(string SQLString)
        {
            using (SqlConnection connection = new SqlConnection(strConn))
            {
                using (SqlCommand cmd = new SqlCommand(SQLString, connection))
                {
                    try
                    {
                        connection.Open();
                        int rows = cmd.ExecuteNonQuery();
                        return rows;
                    }
                    catch (System.Data.SqlClient.SqlException e)
                    {
                        connection.Close();
                        throw e;
                    }
                }
            }
        }

        /// <summary>
        /// 执行查询语句，返回DataTable
        /// </summary>
        /// <param name="SQLString">查询语句</param>
        /// <returns>DataSet</returns>
        public static DataTable Query(string SQLString)
        {
            using (SqlConnection connection = new SqlConnection(strConn))
            {
                DataSet ds = new DataSet();
                try
                {
                    connection.Open();
                    SqlDataAdapter command = new SqlDataAdapter(SQLString, connection);
                    command.Fill(ds, "ds");
                }
                catch (System.Data.SqlClient.SqlException ex)
                {
                    throw new Exception(ex.Message);
                }
                return ds.Tables[0];
            }
        }

三、Access

//using System.Data.OleDb;
public static string OtherPAth = "";
public static string strConn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=";
public static string Sql = String.Empty;
#region 执行简单SQL语句,使用OleDb查询

/// <summary>
/// 执行SQL语句，返回影响的记录数
/// </summary>
/// <param name="SQLString">SQL语句</param>
/// <returns>影响的记录数</returns>
public static int ExecuteSql(string SQLString)
{
using (OleDbConnection connection = new OleDbConnection(strConn + OtherPAth ))
{
using (OleDbCommand cmd = new OleDbCommand(SQLString, connection))
{
try
{
connection.Open();
int rows = cmd.ExecuteNonQuery();
return rows;
}
catch (System.Data.SqlClient.SqlException e)
{
connection.Close();
throw e;
}
}
}
}

/// <summary>
/// 执行查询语句，返回DataTable
/// </summary>
/// <param name="SQLString">查询语句</param>
/// <returns>DataSet</returns>
public static DataTable Query(string SQLString)
{
using (OleDbConnection connection = new OleDbConnection(strConn + OtherPAth))
{
DataSet ds = new DataSet();
try
{
connection.Open();
OleDbDataAdapter command = new OleDbDataAdapter(SQLString, connection);
command.Fill(ds, "ds");
}
catch (Exception ex)
{
System.Windows.Forms.MessageBox.Show(ex.Message);
}
return ds.Tables[0];
}
}

/// <summary>
/// 执行查询语句，返回DataTable
/// </summary>
/// <param name="SQLString">查询语句</param>
/// <returns>DataSet</returns>
public static DataTable QueryDataName()
{
using (OleDbConnection connection = new OleDbConnection(strConn + OtherPAth))
{
DataTable ds = new DataTable();
try
{
connection.Open();
ds = connection.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new object[] { null, null, null, "TABLE" });
}
catch (Exception ex)
{
System.Windows.Forms.MessageBox.Show(ex.Message);
}
return ds;
}
}

#endregion

四、Sqlite

public static string strConn = @"Data Source=" + @"F:资料文档20190629CAD625AnPinCadDLLclDataCad_try0626.db";
public static string Sql = String.Empty;

/// <summary>
/// 执行SQL语句，返回影响的记录数
/// </summary>
/// <param name="SQLString">SQL语句</param>
/// <returns>影响的记录数</returns>
public static int ExecuteSql(string SQLString)
{
using (SQLiteConnection connection = new SQLiteConnection(strConn))
{
//事务
using (SQLiteTransaction singleTrans = connection.BeginTransaction(IsolationLevel.ReadCommitted))
{
using (SQLiteCommand cmd = new SQLiteCommand(SQLString, connection))
{
try
{
connection.Open();
cmd.Transaction = singleTrans;
int rows = cmd.ExecuteNonQuery();
singleTrans.Commit();
return rows;
}
catch (System.Data.SqlClient.SqlException e)
{
connection.Close();
singleTrans.Rollback();
throw e;
}
}
}
}
}

/// <summary>
/// 执行查询语句，返回DataTable
/// </summary>
/// <param name = "SQLString" > 查询语句 </ param >
/// < returns > DataSet </ returns >
public static DataTable Query(string SQLString)
{
using (SQLiteConnection connection = new SQLiteConnection(strConn))
{
DataSet ds = new DataSet();
try
{
connection.Open();
SQLiteDataAdapter command = new SQLiteDataAdapter(SQLString, connection);
command.Fill(ds, "ds");
return ds.Tables[0];
}
catch (Exception ex)
{
connection.Close();
throw ex;
}
}
}

/// <summary>
/// 执行存储过程，返回影响的记录数
/// </summary>
/// <param name="SQLString">SQL语句</param>
/// <returns>影响的记录数</returns>
public static int ExecuteProc(string procName, SQLiteParameter[] coll)
{
using (SQLiteConnection connection = new SQLiteConnection(strConn))
{
//事务
using (SQLiteTransaction singleTrans = connection.BeginTransaction(IsolationLevel.ReadCommitted))
{
using (SQLiteCommand cmd = new SQLiteCommand(connection))
{
try
{
connection.Open();
for (int i = 0; i < coll.Length; i++)
{
cmd.Parameters.Add(coll[i]);
}
cmd.CommandType = CommandType.StoredProcedure;
cmd.CommandText = procName;
cmd.Transaction = singleTrans;
int rows = cmd.ExecuteNonQuery();
singleTrans.Commit();
return rows;
}
catch (System.Data.SqlClient.SqlException e)
{
connection.Close();
singleTrans.Rollback();
throw e;
}
}
}
}
}

/// <summary>
/// 执行带参数的SQL语句，返回影响的记录数
/// </summary>
/// <param name="SQLString">SQL语句</param>
/// <returns>影响的记录数</returns>
public static int ExecuteSqlPar(string sqlPar, SQLiteParameter[] coll)
{
using (SQLiteConnection connection = new SQLiteConnection(strConn))
{
//事务
using (SQLiteTransaction singleTrans = connection.BeginTransaction(IsolationLevel.ReadCommitted))
{
using (SQLiteCommand cmd = new SQLiteCommand(connection))
{
try
{
connection.Open();
for (int i = 0; i < coll.Length; i++)
{
cmd.Parameters.Add(coll[i]);
}
cmd.CommandType = CommandType.Text;
cmd.CommandText = sqlPar;
cmd.Transaction = singleTrans;
int rows = cmd.ExecuteNonQuery();
singleTrans.Commit();
return rows;
}
catch (System.Data.SqlClient.SqlException e)
{
connection.Close();
singleTrans.Rollback();
throw e;
}
}
}
}
}