singSystem;usingSystem.Collections.Generic;usingSystem.Configuration;usingSystem.Data;usingSystem.Data.SqlClient;usingSystem.Linq;usingSystem.Text;usingSystem.Threading.Tasks;namespaceCarHailing.Base{///<summary>///数据库帮助类///</summary>publicclassSqlHelp{///<summary>///创建一个已打开的连接///</summary>///<returns></returns>privatestaticSqlConnectionCreateConn(){SqlConnectionconn=newSqlConnection(ConfigurationManager.ConnectionStrings["conn"].ConnectionString);conn.Open();returnconn;}///<summary>///执行sql语句，返回受影响的行数///</summary>///<paramname="sql"></param>///<returns></returns>publicstaticintExecuteNonQuery(stringsql){returnExecuteNonQuery(sql,null);}///<summary>///执行sql语句，返回受影响的行数///</summary>///<paramname="sql"></param>///<returns></returns>publicstaticintExecuteNonQuery(stringsql,SqlParameter[]ps){SqlConnectionconn=CreateConn();SqlCommandcmd=newSqlCommand(sql,conn);try{if(ps!=null){cmd.Parameters.AddRange(ps);}returncmd.ExecuteNonQuery();}catch(Exceptionex){return0;}finally{conn.Close();}}///<summary>///执行sql语句,返回一个结果表///</summary>///<paramname="sql"></param>///<returns></returns>publicstaticDataTableExecuteSelectDataTable(stringsql){returnExecuteSelectDataTable(sql,null);}///<summary>///执行sql语句,返回一个结果表///</summary>///<paramname="sql"></param>///<paramname="ps"></param>///<returns></returns>publicstaticDataTableExecuteSelectDataTable(stringsql,SqlParameter[]ps=null){SqlConnectionconn=CreateConn();SqlCommandcmd=newSqlCommand(sql,conn);try{if(ps!=null){cmd.Parameters.AddRange(ps);}//SqlDataAdaptersda=newSqlDataAdapter(cmd);SqlDataReaderread=cmd.ExecuteReader();DataTabletable=newDataTable();table.Load(read);//DataSetds=newDataSet();//sda.Fill(ds);returntable;}finally{conn.Close();}}///<summary>//////</summary>///<paramname="sql"></param>///<returns></returns>decimalpublicstaticDataTableExecuteSelectPageDataTable(stringsql,refSqlParameter[]ps){SqlConnectionconn=CreateConn();SqlCommandcmd=newSqlCommand(sql,conn);cmd.CommandType=CommandType.StoredProcedure;try{cmd.Parameters.AddRange(ps);SqlDataAdaptersda=newSqlDataAdapter(cmd);DataSetds=newDataSet();sda.Fill(ds);returnds.Tables[0];}catch(SqlExceptionex){throwex;}finally{conn.Close();}}//publicstaticSqlDataReaderExecuteReader(stringcmdText,CommandTypecmdType,paramsSqlParameter[]cmdParms)//{//SqlCommandcmd=newSqlCommand();//SqlConnectionconn=CreateConn();//try//{//ProCommand(cmd,conn,cmdText,cmdType,cmdParms);//SqlDataReaderrdr=cmd.ExecuteReader(CommandBehavior.CloseConnection);////cmd.Parameters.Clear();//放到这里，返回参数会被清空。//returnrdr;//}//catch//{//conn.Close();//throw;//}//}///<summary>///分页读取数据///</summary>///<paramname="query">select查询语句</param>///<paramname="pageSize">每页显示数据数</param>///<paramname="PageIndex">当前页码</param>///<paramname="dt">存储数据的DataTable实例</param>publicstaticvoidPageDataTable(stringquery,intpageSize,intPageIndex,DataTabledt){//读取数据的开始索引longstartIndex=(PageIndex-1)*pageSize;//读取数据的结束索引longendIndex=PageIndex*pageSize-1;//DataReader读取的当前数据行的索引longreadToIndex=-1;using(SqlConnectionconn=CreateConn()){SqlCommandcmd=newSqlCommand(query,conn);//conn.Open();SqlDataReaderdr=cmd.ExecuteReader();//数据源中的列数intcols=dr.VisibleFieldCount;//构造DataTable结构for(inti=0;i<cols;i++){dt.Columns.Add(newDataColumn(dr.GetName(i),dr.GetFieldType(i)));}//读取数据，将数据一行一行添加到DataTablewhile(dr.Read()){readToIndex++;//当DataReader指针在开始索引和结束索引闭区间时才读取数据构造DataRow//并添加到DataTableif(readToIndex>=startIndex&&readToIndex<=endIndex){DataRowrow=dt.NewRow();for(inti=0;i<cols;i++){row[i]=dr[i];}dt.Rows.Add(row);}}dr.Close();}}}}
//using MySql.Data.MySqlClient;
#region 执行简单SQL语句,使用MySQL查询
static string strConn = "server=.;database=Data20180608;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];
}
}
#endregion
Mysql
#region 执行简单SQL语句,使用SQL SERVER查询
static string strConn = "Data Source=.;database=Data20180608;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];
}
}
#endregion
Sql server
//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
Access
public static string strConn = @"Data Source=" + @"F:\资料文档\20190227\CAD\0625AnPin\CadDLLcl\Data\Cad_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;
}
}
}
}
}
Sqlite
来源：https://www.cnblogs.com/zhang1f/p/11106070.html