c# .netcore oracle连接工具类

1.先右键-》添加NeGet包-》引入Oracle.ManagedDataAccess.dll

2.将该类加入项目中

工具类：

using System;
using System.Collections;
using System.Collections.Specialized;
using System.Data;
using Oracle.ManagedDataAccess.Client;

namespace IRCS.DBUtility
{
    /// <summary>
    /// Copyright (C) Maticsoft
    /// 数据访问基础类(基于Oracle)
    /// 可以用户可以修改满足自己项目的需要。
    /// </summary>
    public abstract class DbHelperOra
    {
        //数据库连接字符串(web.config来配置)，可以动态更改connectionString支持多数据库.
        public static string connectionString = PubConstant.ConnectionString;
        public DbHelperOra()
        {
        }

        #region 公用方法

        public static int GetMaxID(string FieldName, string TableName)
        {
            string strsql = "select max(" + FieldName + ")+1 from " + TableName;
            object obj = GetSingle(strsql);
            if (obj == null)
            {
                return ;
            }
            else
            {
                return int.Parse(obj.ToString());
            }
        }

        public static long GetLongMaxID(string FieldName, string TableName)
        {
            string strsql = "select max(" + FieldName + ")+1 from " + TableName;
            object obj = GetSingle(strsql);
            if (obj == null)
            {
                return ;
            }
            else
            {
                return long.Parse(obj.ToString());
            }
        }

        public static bool Exists(string strSql)
        {
            object obj = GetSingle(strSql);
            int cmdresult;
            if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
            {
                cmdresult = ;
            }
            else
            {
                cmdresult = int.Parse(obj.ToString());
            }
            if (cmdresult == )
            {
                return false;
            }
            else
            {
                return true;
            }
        }

        public static bool Exists(string strSql, params OracleParameter[] cmdParms)
        {
            object obj = GetSingle(strSql, cmdParms);
            int cmdresult;
            if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
            {
                cmdresult = ;
            }
            else
            {
                cmdresult = int.Parse(obj.ToString());
            }
            if (cmdresult == )
            {
                return false;
            }
            else
            {
                return true;
            }
        }

        #endregion

        #region  执行简单SQL语句

        /// <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 (OracleConnection connection = new OracleConnection(connectionString))
            {
                using (OracleCommand cmd = new OracleCommand(SQLString,connection))
                {
                    try
                    {
                        connection.Open();
                        int rows=cmd.ExecuteNonQuery();
                        return rows;
                    }
                    catch(OracleException E)
                    {
                        connection.Close();
                        throw new Exception(E.Message);
                    }
                }
            }
        }

        /// <summary>
        /// 执行多条SQL语句，实现数据库事务。
        /// </summary>
        /// <param name="SQLStringList">多条SQL语句</param>
        public static void ExecuteSqlTran(ArrayList SQLStringList)
        {
            using (OracleConnection conn = new OracleConnection(connectionString))
            {
                conn.Open();
                OracleCommand cmd = new OracleCommand();
                cmd.Connection=conn;
                OracleTransaction tx=conn.BeginTransaction();
                cmd.Transaction=tx;
                try
                {
                    for(int n=;n<SQLStringList.Count;n++)
                    {
                        string strsql=SQLStringList[n].ToString();
                        if (strsql.Trim().Length>)
                        {
                            cmd.CommandText=strsql;
                            cmd.ExecuteNonQuery();
                        }
                    }
                    tx.Commit();
                }
                catch(OracleException E)
                {
                    tx.Rollback();
                    throw new Exception(E.Message);
                }
            }
        }
        /// <summary>
        /// 执行带一个存储过程参数的的SQL语句。
        /// </summary>
        /// <param name="SQLString">SQL语句</param>
        /// <param name="content">参数内容,比如一个字段是格式复杂的文章，有特殊符号，可以通过这个方式添加</param>
        /// <returns>影响的记录数</returns>
        public static int ExecuteSql(string SQLString,string content)
        {
            using (OracleConnection connection = new OracleConnection(connectionString))
            {
                OracleCommand cmd = new OracleCommand(SQLString,connection);
                OracleParameter myParameter = new OracleParameter("@content", OracleDbType.NVarchar2);
                myParameter.Value = content ;
                cmd.Parameters.Add(myParameter);
                try
                {
                    connection.Open();
                    int rows=cmd.ExecuteNonQuery();
                    return rows;
                }
                catch(OracleException E)
                {
                    throw new Exception(E.Message);
                }
                finally
                {
                    cmd.Dispose();
                    connection.Close();
                }
            }
        }
        /// <summary>
        /// 向数据库里插入图像格式的字段(和上面情况类似的另一种实例)
        /// </summary>
        /// <param name="strSQL">SQL语句</param>
        /// <param name="fs">图像字节,数据库的字段类型为image的情况</param>
        /// <returns>影响的记录数</returns>
        public static int ExecuteSqlInsertImg(string strSQL,byte[] fs)
        {
            using (OracleConnection connection = new OracleConnection(connectionString))
            {
                OracleCommand cmd = new OracleCommand(strSQL,connection);
                OracleParameter myParameter = new OracleParameter("@fs", OracleDbType.LongRaw);
                myParameter.Value = fs ;
                cmd.Parameters.Add(myParameter);
                try
                {
                    connection.Open();
                    int rows=cmd.ExecuteNonQuery();
                    return rows;
                }
                catch(OracleException E)
                {
                    throw new Exception(E.Message);
                }
                finally
                {
                    cmd.Dispose();
                    connection.Close();
                }
            }
        }

        /// <summary>
        /// 执行一条计算查询结果语句，返回查询结果（object）。
        /// </summary>
        /// <param name="SQLString">计算查询结果语句</param>
        /// <returns>查询结果（object）</returns>
        public static object GetSingle(string SQLString)
        {
            using (OracleConnection connection = new OracleConnection(connectionString))
            {
                using(OracleCommand cmd = new OracleCommand(SQLString,connection))
                {
                    try
                    {
                        connection.Open();
                        object obj = cmd.ExecuteScalar();
                        if((Object.Equals(obj,null))||(Object.Equals(obj,System.DBNull.Value)))
                        {
                            return null;
                        }
                        else
                        {
                            return obj;
                        }
                    }
                    catch(OracleException e)
                    {
                        connection.Close();
                        throw new Exception(e.Message);
                    }
                }
            }
        }
        /// <summary>
        /// 执行查询语句，返回OracleDataReader ( 注意：调用该方法后，一定要对SqlDataReader进行Close )
        /// </summary>
        /// <param name="strSQL">查询语句</param>
        /// <returns>OracleDataReader</returns>
        public static OracleDataReader ExecuteReader(string strSQL)
        {
            OracleConnection connection = new OracleConnection(connectionString);
            OracleCommand cmd = new OracleCommand(strSQL,connection);
            try
            {
                connection.Open();
                OracleDataReader myReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
                return myReader;
            }
            catch(OracleException e)
            {
                throw new Exception(e.Message);
            }            

        }
        /// <summary>
        /// 执行查询语句，返回DataSet
        /// </summary>
        /// <param name="SQLString">查询语句</param>
        /// <returns>DataSet</returns>
        public static DataSet Query(string SQLString)
        {
            using (OracleConnection connection = new OracleConnection(connectionString))
            {
                DataSet ds = new DataSet();
                try
                {
                    connection.Open();
                    OracleDataAdapter command = new OracleDataAdapter(SQLString,connection);
                    command.Fill(ds,"ds");
                }
                catch(OracleException ex)
                {
                    throw new Exception(ex.Message);
                }
                return ds;
            }
        }

        #endregion

        #region 执行带参数的SQL语句

        /// <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,params OracleParameter[] cmdParms)
        {
            using (OracleConnection connection = new OracleConnection(connectionString))
            {
                using (OracleCommand cmd = new OracleCommand())
                {
                    try
                    {
                        PrepareCommand(cmd, connection, null,SQLString, cmdParms);
                        int rows=cmd.ExecuteNonQuery();
                        cmd.Parameters.Clear();
                        return rows;
                    }
                    catch(OracleException E)
                    {
                        throw new Exception(E.Message);
                    }
                }
            }
        }

        /// <summary>
        /// 执行多条SQL语句，实现数据库事务。
        /// </summary>
        /// <param name="SQLStringList">SQL语句的哈希表（key为sql语句，value是该语句的OracleParameter[]）</param>
        public static void ExecuteSqlTran(Hashtable SQLStringList)
        {
            using (OracleConnection conn = new OracleConnection(connectionString))
            {
                conn.Open();
                using (OracleTransaction trans = conn.BeginTransaction())
                {
                    OracleCommand cmd = new OracleCommand();
                    try
                    {
                        //循环
                        foreach (DictionaryEntry myDE in SQLStringList)
                        {
                            string     cmdText=myDE.Key.ToString();
                            OracleParameter[] cmdParms=(OracleParameter[])myDE.Value;
                            PrepareCommand(cmd,conn,trans,cmdText, cmdParms);
                            int val = cmd.ExecuteNonQuery();
                            cmd.Parameters.Clear();

                            trans.Commit();
                        }
                    }
                    catch
                    {
                        trans.Rollback();
                        throw;
                    }
                }
            }
        }

        /// <summary>
        /// 执行一条计算查询结果语句，返回查询结果（object）。
        /// </summary>
        /// <param name="SQLString">计算查询结果语句</param>
        /// <returns>查询结果（object）</returns>
        public static object GetSingle(string SQLString,params OracleParameter[] cmdParms)
        {
            using (OracleConnection connection = new OracleConnection(connectionString))
            {
                using (OracleCommand cmd = new OracleCommand())
                {
                    try
                    {
                        PrepareCommand(cmd, connection, null,SQLString, cmdParms);
                        object obj = cmd.ExecuteScalar();
                        cmd.Parameters.Clear();
                        if((Object.Equals(obj,null))||(Object.Equals(obj,System.DBNull.Value)))
                        {
                            return null;
                        }
                        else
                        {
                            return obj;
                        }
                    }
                    catch(OracleException e)
                    {
                        throw new Exception(e.Message);
                    }
                }
            }
        }

        /// <summary>
        /// 执行查询语句，返回OracleDataReader ( 注意：调用该方法后，一定要对SqlDataReader进行Close )
        /// </summary>
        /// <param name="strSQL">查询语句</param>
        /// <returns>OracleDataReader</returns>
        public static OracleDataReader ExecuteReader(string SQLString,params OracleParameter[] cmdParms)
        {
            OracleConnection connection = new OracleConnection(connectionString);
            OracleCommand cmd = new OracleCommand();
            try
            {
                PrepareCommand(cmd, connection, null,SQLString, cmdParms);
                OracleDataReader myReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
                cmd.Parameters.Clear();
                return myReader;
            }
            catch(OracleException e)
            {
                throw new Exception(e.Message);
            }                    

        }        

        /// <summary>
        /// 执行查询语句，返回DataSet
        /// </summary>
        /// <param name="SQLString">查询语句</param>
        /// <returns>DataSet</returns>
        public static DataSet Query(string SQLString,params OracleParameter[] cmdParms)
        {
            using (OracleConnection connection = new OracleConnection(connectionString))
            {
                OracleCommand cmd = new OracleCommand();
                PrepareCommand(cmd, connection, null,SQLString, cmdParms);
                using( OracleDataAdapter da = new OracleDataAdapter(cmd) )
                {
                    DataSet ds = new DataSet();
                    try
                    {
                        da.Fill(ds,"ds");
                        cmd.Parameters.Clear();
                    }
                    catch(OracleException ex)
                    {
                        throw new Exception(ex.Message);
                    }
                    return ds;
                }
            }
        }

        private static void PrepareCommand(OracleCommand cmd,OracleConnection conn,OracleTransaction trans, string cmdText, OracleParameter[] cmdParms)
        {
            if (conn.State != ConnectionState.Open)
                conn.Open();
            cmd.Connection = conn;
            cmd.CommandText = cmdText;
            if (trans != null)
                cmd.Transaction = trans;
            cmd.CommandType = CommandType.Text;//cmdType;
            if (cmdParms != null)
            {
                foreach (OracleParameter parm in cmdParms)
                    cmd.Parameters.Add(parm);
            }
        }

        #endregion

        #region 存储过程操作

        /// <summary>
        /// 执行存储过程 返回SqlDataReader ( 注意：调用该方法后，一定要对SqlDataReader进行Close )
        /// </summary>
        /// <param name="storedProcName">存储过程名</param>
        /// <param name="parameters">存储过程参数</param>
        /// <returns>OracleDataReader</returns>
        public static OracleDataReader RunProcedure(string storedProcName, IDataParameter[] parameters )
        {
            OracleConnection connection = new OracleConnection(connectionString);
            OracleDataReader returnReader;
            connection.Open();
            OracleCommand command = BuildQueryCommand( connection,storedProcName, parameters );
            command.CommandType = CommandType.StoredProcedure;
            returnReader = command.ExecuteReader(CommandBehavior.CloseConnection);
            return returnReader;
        }

        /// <summary>
        /// 执行存储过程
        /// </summary>
        /// <param name="storedProcName">存储过程名</param>
        /// <param name="parameters">存储过程参数</param>
        /// <param name="tableName">DataSet结果中的表名</param>
        /// <returns>DataSet</returns>
        public static DataSet RunProcedure(string storedProcName, IDataParameter[] parameters, string tableName )
        {
            using (OracleConnection connection = new OracleConnection(connectionString))
            {
                DataSet dataSet = new DataSet();
                connection.Open();
                OracleDataAdapter sqlDA = new OracleDataAdapter();
                sqlDA.SelectCommand = BuildQueryCommand(connection, storedProcName, parameters );
                sqlDA.Fill( dataSet, tableName );
                connection.Close();
                return dataSet;
            }
        }

        /// <summary>
        /// 构建 OracleCommand 对象(用来返回一个结果集，而不是一个整数值)
        /// </summary>
        /// <param name="connection">数据库连接</param>
        /// <param name="storedProcName">存储过程名</param>
        /// <param name="parameters">存储过程参数</param>
        /// <returns>OracleCommand</returns>
        private static OracleCommand BuildQueryCommand(OracleConnection connection,string storedProcName, IDataParameter[] parameters)
        {
            OracleCommand command = new OracleCommand( storedProcName, connection );
            command.CommandType = CommandType.StoredProcedure;
            foreach (OracleParameter parameter in parameters)
            {
                command.Parameters.Add( parameter );
            }
            return command;
        }

        /// <summary>
        /// 执行存储过程，返回影响的行数
        /// </summary>
        /// <param name="storedProcName">存储过程名</param>
        /// <param name="parameters">存储过程参数</param>
        /// <param name="rowsAffected">影响的行数</param>
        /// <returns></returns>
        public static int RunProcedure(string storedProcName, IDataParameter[] parameters, out int rowsAffected )
        {
            using (OracleConnection connection = new OracleConnection(connectionString))
            {
                int result;
                connection.Open();
                OracleCommand command = BuildIntCommand(connection,storedProcName, parameters );
                rowsAffected = command.ExecuteNonQuery();
                result = (int)command.Parameters["ReturnValue"].Value;
                //Connection.Close();
                return result;
            }
        }

        /// <summary>
        /// 创建 OracleCommand 对象实例(用来返回一个整数值)
        /// </summary>
        /// <param name="storedProcName">存储过程名</param>
        /// <param name="parameters">存储过程参数</param>
        /// <returns>OracleCommand 对象实例</returns>
        private static OracleCommand BuildIntCommand(OracleConnection connection,string storedProcName, IDataParameter[] parameters)
        {
            OracleCommand command = BuildQueryCommand(connection,storedProcName, parameters );
            command.Parameters.Add( new OracleParameter ( "ReturnValue",
                OracleDbType.Int32, , ParameterDirection.ReturnValue,
                false,,,string.Empty,DataRowVersion.Default,null ));
            return command;
        }
        #endregion    

    }
}

加载配置文件，初始化

 /// <summary>
    /// 读取配置文件
    /// </summary>
    public class AppConfigurtaionServices
    {
        public static IConfiguration Configuration { get; set; }
        static AppConfigurtaionServices()
        {
            //ReloadOnChange = true 当appsettings.json被修改时重新加载
            Configuration = new ConfigurationBuilder()
            .Add(new JsonConfigurationSource { Path = "appsettings.json", ReloadOnChange = true })
            .Build();
        }
    }

获取app.config配置文件中的数据库连接的拓展类：

using IRCS.Common;
using Microsoft.Extensions.Configuration;
using System;
namespace IRCS.DBUtility
{

    public class PubConstant
    {
        /// <summary>
        /// 获取连接字符串
        /// </summary>
        public static string ConnectionString
        {
            get
            {
                try
                {
                    string _connectionString = AppConfigurtaionServices.Configuration["Appsettings:ConnectionString"];
                    return _connectionString;
                }
                catch (Exception e)
                {
                    throw e;
                }
            }
        }

        public static string ConnectionString_MySQL
        {
            get
            {
                try
                {
                    string _connectionString = AppConfigurtaionServices.Configuration["Appsettings:ConnectionString_MYSQL"];
                    return _connectionString;
                }
                catch (Exception e)
                {
                    throw e;
                }
            }
        }

        public static string ConnectionString_NpgSQL
        {
            get
            {

                string _connectionString = AppConfigurtaionServices.Configuration["Appsettings:ConnectionString_NpgSQL"];
                return _connectionString;
            }
        }

    }
}

如：