为什么我从 .net 上的 Ormlite 得到“从范围引用但未定义的变量”错误，但它在 Mono 上运行良好？

Question

我正在使用 ServiceStack Ormlite。我的代码是这样的：

var number = _conn.Count<Lot>(lot => lot.Labels.Contains("lookingString"));

我的问题是代码在 Mono 上运行良好，但在 .Net 框架中出现错误：

Message: [InvalidOperationException: variable 'lot' of type 'pM.Models.Entity.Lot' referenced from scope '', but it is not defined]

 System.Linq.Expressions.Compiler.VariableBinder.Reference(ParameterExpression node, VariableStorageKind storage):142
 System.Linq.Expressions.Compiler.VariableBinder.VisitParameter(ParameterExpression node):10
 System.Linq.Expressions.Compiler.VariableBinder.VisitUnary(UnaryExpression node):59
 System.Linq.Expressions.ExpressionVisitor.VisitMember(MemberExpression node):13
 System.Linq.Expressions.ExpressionVisitor.VisitMethodCall(MethodCallExpression node):12
 System.Linq.Expressions.ExpressionVisitor.Visit(ReadOnlyCollection`1 nodes):26
 System.Linq.Expressions.Compiler.VariableBinder.VisitLambda[T](Expression`1 node):88
 System.Linq.Expressions.Compiler.LambdaCompiler.Compile(LambdaExpression lambda, DebugInfoGenerator debugInfoGenerator):0
 ServiceStack.OrmLite.SqlExpression`1.VisitMethodCall(MethodCallExpression m):87
 ServiceStack.OrmLite.SqlExpression`1.VisitBinary(BinaryExpression b):135
 ServiceStack.OrmLite.SqlExpression`1.Where(Expression`1 predicate):12
 ServiceStack.OrmLite.ReadExpressionCommandExtensions.Scalar[T,TKey](IDbCommand dbCmd, Expression`1 field, Expression`1 predicate):26
 ServiceStack.OrmLite.OrmLiteExecFilter.Exec[T](IDbConnection dbConn, Func`2 filter):16
 pM.Api.LabelReadHelper.GetUsage[T](String labelName) in c:\TeamCity\buildAgent\work\b85b83a981467d5b\pM.Api\Common\Labels\Template\LabelReadHelper.cs:23

在 Mono 上，像这样的 LastSql :

SELECT COUNT(*) FROM `Lot` WHERE (upper(`Labels`) like '%lookingString%' AND (`CustomerId` = 'a54f02ee-cc74-4b4d-845d-6db2efb1f5dc'));

我的 ServiceStack.Ormlite 版本是 4.0.50。

不同平台的 Contains 方法是否不同？

Answer 1

这适用于 OrmLite 的最新 v4.0.62，您可以 try out Live in Gistlyn:

public class Lot
{
    [AutoIncrement]
    public long Id { get; set; }
    public string Labels { get; set; }
}

db.CreateTable<Lot>();

db.Insert(new Lot { Labels = "foo" });
db.Insert(new Lot { Labels = "bar" });
db.Insert(new Lot { Labels = "qux" });
db.Insert(new Lot { Labels = "foo,bar,qux" });

var count = db.Count<Lot>(x => x.Labels.Contains("bar"));

"Labels with 'bar': {0}".Print(count); //= 2

它在 Mono/Linux 中具有相同的行为，您可以使用 mono.gistlyn.com 来尝试，例如：

http://gistlyn.com/?gist=2bc6769ff2e85388b79f9cb1572292d5 (Windows)
http://mono.gistlyn.com/?gist=2bc6769ff2e85388b79f9cb1572292d5（单声道）

为什么我从 .net 上的 Ormlite 得到“从范围引用但未定义的变量”错误，但它在 Mono 上运行良好？

Why do I get “variable referenced from scope but not defined” error from Ormlite on .net, but it works well on Mono?

servicestack

ormlite-servicestack