/PetaPoco/OracleProvider.cs

  1using System;
  2using System.Data.Common;
  3using System.Reflection;
  4
  5namespace PetaPoco
  6{
  7    /* 
  8	Thanks to Adam Schroder (@schotime) for this.
  9	
 10	This extra file provides an implementation of DbProviderFactory for early versions of the Oracle
 11	drivers that don't include include it.  For later versions of Oracle, the standard OracleProviderFactory
 12	class should work fine
 13	
 14	Uses reflection to load Oracle.DataAccess assembly and in-turn create connections and commands
 15	
 16	Currently untested.
 17	
 18	Usage:   
 19		
 20			new PetaPoco.Database("<connstring>", new PetaPoco.OracleProvider())
 21	
 22	Or in your app/web config (be sure to change ASSEMBLYNAME to the name of your 
 23	assembly containing OracleProvider.cs)
 24	
 25		<connectionStrings>
 26			<add
 27				name="oracle"
 28				connectionString="WHATEVER"
 29				providerName="Oracle"
 30				/>
 31		</connectionStrings>
 32
 33		<system.data>
 34			<DbProviderFactories>
 35				<add name="PetaPoco Oracle Provider" invariant="Oracle" description="PetaPoco Oracle Provider" 
 36								type="PetaPoco.OracleProvider, ASSEMBLYNAME" />
 37			</DbProviderFactories>
 38		</system.data>
 39
 40	 */
 41
 42    public class OracleProvider : DbProviderFactory
 43    {
 44        private const string _assemblyName = "Oracle.DataAccess";
 45        private const string _connectionTypeName = "Oracle.DataAccess.Client.OracleConnection";
 46        private const string _commandTypeName = "Oracle.DataAccess.Client.OracleCommand";
 47        private static Type _connectionType;
 48        private static Type _commandType;
 49
 50        // Required for DbProviderFactories.GetFactory() to work.
 51        public static OracleProvider Instance = new OracleProvider();
 52
 53        public OracleProvider()
 54        {
 55            _connectionType = TypeFromAssembly(_connectionTypeName, _assemblyName);
 56            _commandType = TypeFromAssembly(_commandTypeName, _assemblyName);
 57            if (_connectionType == null)
 58                throw new InvalidOperationException("Can't find Connection type: " + _connectionTypeName);
 59        }
 60
 61        public override DbConnection CreateConnection()
 62        {
 63            return (DbConnection) Activator.CreateInstance(_connectionType);
 64        }
 65
 66        public override DbCommand CreateCommand()
 67        {
 68            DbCommand command = (DbCommand) Activator.CreateInstance(_commandType);
 69
 70            var oracleCommandBindByName = _commandType.GetProperty("BindByName");
 71            oracleCommandBindByName.SetValue(command, true, null);
 72
 73            return command;
 74        }
 75
 76        public static Type TypeFromAssembly(string typeName, string assemblyName)
 77        {
 78            try
 79            {
 80                // Try to get the type from an already loaded assembly
 81                Type type = Type.GetType(typeName);
 82
 83                if (type != null)
 84                {
 85                    return type;
 86                }
 87
 88                if (assemblyName == null)
 89                {
 90                    // No assembly was specified for the type, so just fail
 91                    string message = "Could not load type " + typeName + ". Possible cause: no assembly name specified.";
 92                    throw new TypeLoadException(message);
 93                }
 94
 95                Assembly assembly = Assembly.Load(assemblyName);
 96
 97                if (assembly == null)
 98                {
 99                    throw new InvalidOperationException("Can't find assembly: " + assemblyName);
100                }
101
102                type = assembly.GetType(typeName);
103
104                if (type == null)
105                {
106                    return null;
107                }
108
109                return type;
110            }
111            catch (Exception)
112            {
113                return null;
114            }
115        }
116    }
117}