这对我来说很管用:

bool hasColumnName = reader.GetSchemaTable().AsEnumerable().Any(c => c["ColumnName"] == "YOUR_COLUMN_NAME");

在一行中，在DataReader检索后使用:

var fieldNames = Enumerable.Range(0, dr.FieldCount).Select(i => dr.GetName(i)).ToArray();

然后,

if (fieldNames.Contains("myField"))
{
    var myFieldValue = dr["myField"];
    ...

Edit

更高效的单行程序，不需要加载模式:

var exists = Enumerable.Range(0, dr.FieldCount).Any(i => string.Equals(dr.GetName(i), fieldName, StringComparison.OrdinalIgnoreCase));

整个问题的关键在这里:

if (-1 == index) {
    throw ADP.IndexOutOfRange(fieldName);
}

如果引用的三行(目前是第72、73和74行)被删除，那么您可以很容易地检查-1，以确定列是否不存在。

确保本机性能的唯一方法是使用基于反射的实现，如下所示:

Usings:

using System;
using System.Data;
using System.Reflection;
using System.Data.SqlClient;
using System.Linq;
using System.Web.Compilation; // I'm not sure what the .NET Core equivalent to BuildManager.cs

基于反射的扩展方法:

/// Gets the column ordinal, given the name of the column.
/// </summary>
/// <param name="reader"></param>
/// <param name="name">The name of the column.</param>
/// <returns> The zero-based column ordinal. -1 if the column does not exist.</returns>
public static int GetOrdinalSoft(this SqlDataReader reader, string name)
{
    try
    {
        // Note that "Statistics" will not be accounted for in this implemenation
        // If you have SqlConnection.StatisticsEnabled set to true (the default is false), you probably don't want to use this method
        // All of the following logic is inspired by the actual implementation of the framework:
        // https://referencesource.microsoft.com/#System.Data/fx/src/data/System/Data/SqlClient/SqlDataReader.cs,d66096b6f57cac74
        if (name == null)
            throw new ArgumentNullException("fieldName");

        Type sqlDataReaderType = typeof(SqlDataReader);
        object fieldNameLookup = sqlDataReaderType.GetField("_fieldNameLookup", BindingFlags.NonPublic | BindingFlags.Instance).GetValue(reader);
        Type fieldNameLookupType;
        if (fieldNameLookup == null)
        {
            MethodInfo checkMetaDataIsReady = sqlDataReaderType.GetRuntimeMethods().First(x => x.Name == "CheckMetaDataIsReady" && x.GetParameters().Length == 0);
            checkMetaDataIsReady.Invoke(reader, null);
            fieldNameLookupType = BuildManager.GetType("System.Data.ProviderBase.FieldNameLookup", true, false);
            ConstructorInfo ctor = fieldNameLookupType.GetConstructor(new[] { typeof(SqlDataReader), typeof(int) });
            fieldNameLookup = ctor.Invoke(new object[] { reader, sqlDataReaderType.GetField("_defaultLCID", BindingFlags.NonPublic | BindingFlags.Instance).GetValue(reader) });
        }
        else
            fieldNameLookupType = fieldNameLookup.GetType();

        MethodInfo indexOf = fieldNameLookupType.GetMethod("IndexOf", BindingFlags.Public | BindingFlags.Instance, null, new Type[] { typeof(string) }, null);

        return (int)indexOf.Invoke(fieldNameLookup, new object[] { name });
    }
    catch
    {
        // .NET Implemenation might have changed, revert back to the classic solution.
        if (reader.FieldCount > 11) // Performance observation by b_levitt
        {
            try
            {
                return reader.GetOrdinal(name);
            }
            catch
            {
                return -1;
            }
        }
        else
        {
            var exists = Enumerable.Range(0, reader.FieldCount).Any(i => string.Equals(reader.GetName(i), name, StringComparison.OrdinalIgnoreCase));
            if (exists)
                return reader.GetOrdinal(name);
            else
                return -1;
        }
    }
}

这对我来说很管用:

bool hasColumnName = reader.GetSchemaTable().AsEnumerable().Any(c => c["ColumnName"] == "YOUR_COLUMN_NAME");

Use:

if(Enumerable.Range(0,reader.FieldCount).Select(reader.GetName).Contains("columName"))
{
     employee.EmployeeId= Utility.ConvertReaderToLong(reader["EmployeeId"]);
}

你可以从can You get the column names from a SqlDataReader获取更多详细信息。

以下是Jasmin想法的工作示例:

var cols = r.GetSchemaTable().Rows.Cast<DataRow>().Select
    (row => row["ColumnName"] as string).ToList(); 

if (cols.Contains("the column name"))
{

}