在哪里可以找到ODP到CLR类型映射的列表？ 在Oracle数据库中，NUMBER（9,0）类型在.NET应用程序中作为System.Decimal从MS Oracle驱动程序中出现，但作为来自ODP驱动程序的System.Int32。我需要从数据库中出来的确切类型（不是CLR到DB参数映射）。
答案 0 :(得分：4)
运行此简单测试以获取SqlServer和Oracle（MS和ODP.NET驱动程序）的映射：
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using Oracle.DataAccess.Client;
namespace DbOutTypeTest
{
public class Program
{
private static string SqlServerConnectionString = @"";
private static string OracleConnectionString = @"";
private static void WriteHeader(string title)
{
Console.WriteLine("----------------------------------------------------------");
Console.WriteLine("-- {0}", title);
Console.WriteLine("----------------------------------------------------------");
}
private static void WriteRow(string key, string value)
{
Console.WriteLine("{0}\t\t{1}", key.PadRight(30, ' '), value);
}
private static void EnumerateTypes(IDbConnection connection, string template, IEnumerable<string> types)
{
EnumerateTypes(connection, template, types, (arg1, arg2) => { });
}
private static void EnumerateTypes(IDbConnection connection, string template, IEnumerable<string> types, Action<string, string> action)
{
connection.Open();
using (var command = connection.CreateCommand())
{
foreach (var type in types)
{
var value = "";
command.CommandText = string.Format(template, type);
try
{
using (var reader = command.ExecuteReader())
{
if (reader.Read())
value = reader[0].GetType().FullName;
else
value = "<no data read>";
}
}
catch (Exception ex)
{
value = ex.Message;
}
WriteRow(type, value);
action(type, value);
}
}
}
private static IEnumerable<string> SqlServerIntegers()
{
yield return "tinyint";
yield return "smallint";
yield return "int";
yield return "bigint";
for (int precision = 1; precision <= 38; ++precision)
{
yield return "numeric(" + precision + ", 0)";
}
yield break;
}
private static IEnumerable<string> SqlServerFloatings()
{
yield return "real";
yield return "float";
for (int precision = 1; precision <= 38; ++precision)
{
for (int scale = 1; scale <= precision; ++scale)
yield return "numeric(" + precision + ", " + scale + ")";
}
yield break;
}
private static IEnumerable<string> OracleIntegers()
{
for (int precision = 1; precision <= 38; ++precision)
{
yield return "number(" + precision + ", 0)";
}
yield break;
}
private static IEnumerable<string> OracleFloatings()
{
for (int precision = 1; precision <= 38; ++precision)
{
for (int scale = 1; scale <= precision; ++scale)
yield return "number(" + precision + ", " + scale + ")";
}
yield break;
}
public static void Main(string[] args)
{
WriteHeader("C# types - CLR names");
Console.WriteLine("{0}\t\t{1}", "byte".PadRight(30, ' '), typeof(byte).FullName);
Console.WriteLine("{0}\t\t{1}", "short".PadRight(30, ' '), typeof(short).FullName);
Console.WriteLine("{0}\t\t{1}", "int".PadRight(30, ' '), typeof(int).FullName);
Console.WriteLine("{0}\t\t{1}", "long".PadRight(30, ' '), typeof(long).FullName);
Console.WriteLine("{0}\t\t{1}", "float".PadRight(30, ' '), typeof(float).FullName);
Console.WriteLine("{0}\t\t{1}", "double".PadRight(30, ' '), typeof(double).FullName);
var OracleToClrInteger = new Dictionary<string, string>();
var OracleToClrFloating = new Dictionary<string, string>();
var SqlServerToClrInteger = new Dictionary<string, string>();
var SqlServerToClrFloating = new Dictionary<string, string>();
WriteHeader("Oracle integers mapping (Oracle Data Provider)");
using (var connection = new OracleConnection(OracleConnectionString))
{
EnumerateTypes(connection, "SELECT CAST(0 AS {0}) FROM DUAL", OracleIntegers(), (type, value) => OracleToClrInteger.Add(type, value));
}
WriteHeader("SQLServer integers mapping");
using (var connection = new SqlConnection(SqlServerConnectionString))
{
EnumerateTypes(connection, "SELECT CAST(0 AS {0})", SqlServerIntegers(), (type, value) => SqlServerToClrInteger.Add(type, value));
}
WriteHeader("Oracle integers mapping (Microsoft Oracle Client)");
using (var connection = new System.Data.OracleClient.OracleConnection(OracleConnectionString))
{
EnumerateTypes(connection, "SELECT CAST(0 AS {0}) FROM DUAL", OracleIntegers());
}
WriteHeader("Oracle floats mapping (Oracle Data Provider)");
using (var connection = new OracleConnection(OracleConnectionString))
{
EnumerateTypes(connection, "SELECT CAST(0 AS {0}) FROM DUAL", OracleFloatings(), (type, value) => OracleToClrFloating.Add(type, value));
}
WriteHeader("SQLServer floats mapping");
using (var connection = new SqlConnection(SqlServerConnectionString))
{
EnumerateTypes(connection, "SELECT CAST(0 AS {0})", SqlServerFloatings(), (type, value) => SqlServerToClrFloating.Add(type, value));
}
WriteHeader("Oracle floats mapping (Microsoft Oracle Client)");
using (var connection = new System.Data.OracleClient.OracleConnection(OracleConnectionString))
{
EnumerateTypes(connection, "SELECT CAST(0 AS {0}) FROM DUAL", OracleFloatings());
}
WriteHeader("Suggested integer type mapping Oracle -> SqlServer");
foreach (var pair in OracleToClrInteger)
{
if (pair.Value == "System.Decimal")
WriteRow(pair.Key, pair.Key.Replace("number", "numeric"));
else
{
if (!SqlServerToClrInteger.Values.Contains(pair.Value))
WriteRow(pair.Key, "???");
else
WriteRow(pair.Key, SqlServerToClrInteger.First(p => p.Value == pair.Value).Key);
}
}
WriteHeader("Suggested floating type mapping Oracle -> SqlServer");
foreach (var pair in OracleToClrFloating)
{
if (pair.Value == "System.Decimal")
WriteRow(pair.Key, pair.Key.Replace("number", "numeric"));
else
{
if (!SqlServerToClrFloating.Values.Contains(pair.Value))
WriteRow(pair.Key, "???");
else
WriteRow(pair.Key, SqlServerToClrFloating.First(p => p.Value == pair.Value).Key);
}
}
}
}
}
最有趣的部分：
----------------------------------------------------------
-- Oracle integers mapping (Oracle Data Provider)
----------------------------------------------------------
number(1, 0) System.Int16
number(2, 0) System.Int16
number(3, 0) System.Int16
number(4, 0) System.Int16
number(5, 0) System.Int32
number(6, 0) System.Int32
number(7, 0) System.Int32
number(8, 0) System.Int32
number(9, 0) System.Int32
number(10, 0) System.Int64
number(11, 0) System.Int64
number(12, 0) System.Int64
number(13, 0) System.Int64
number(14, 0) System.Int64
number(15, 0) System.Int64
number(16, 0) System.Int64
number(17, 0) System.Int64
number(18, 0) System.Int64
number(19, 0) System.Decimal
number(20, 0) System.Decimal
number(21, 0) System.Decimal
number(22, 0) System.Decimal
number(23, 0) System.Decimal
number(24, 0) System.Decimal
答案 1 :(得分：3)
的Stefan， 我自己也有同样的问题。
您可以在已安装的DevArt DotConnect for Oracle帮助文档中找到答案： MS-帮助：//Devart.Data.Oracle/dcOracle/DataTypeMapping.html
您可能想在线浏览，在DevArt的网站上查找相同的信息： http://www.devart.com/dotconnect/oracle/docs/DataTypeMapping.html
两者都在题为“实体框架数据类型映射”的章节下。
“Oracle到.NET类型映射 - 使用Visual Studio 2008/2010中的实体数据模型向导和实体开发人员中的数据库反向工程向导从数据库生成模型时，将使用此表中的类型映射规则。“