当使用具有隐式参数和显式参数的DataContext.ExecuteQuery时，为什么会获得不同的运行时？

Question

我有一个包含TFS构建的测试程序集统计信息的表，如下所示：

AssemblyName   Duration      TestResults    MsPerResult Branch
Ass1.dll            100                2             50     $/branch1
Ass2.dll            200                2            100     $/branch1/sub1
Ass3.dll            400                2            200     $/branch1/sub1/subsub1
...

此外，我有一个用于保存DataContext.ExecuteQuery＆lt;＆gt;的摘要类。结果

public class AssemblyStatistics
{
    public string AssemblyName { get; set; }
    public int TestResultCount { get; set; }
    public long ValueInMs { get; set; }
}

如果我执行以下代码，我的查询总是花费相同的时间，即使我限制只查询子分支的结果：

context.ExecuteQuery<AssemblyStatistics>(
  "SELECT TOP 10 AssemblyName, SUM(Duration) AS ValueInMs, SUM(TestResults) AS TestResultCount FROM AssembliesByDuration WHERE Branch LIKE {0} GROUP BY AssemblyName ORDER BY SUM(Duration) DESC", "$/branch1/sub1%").ToList();

但是使用以下（非websafe）格式，运行时按预期方式下降

context.ExecuteQuery<AssemblyStatistics>(
  @"SELECT TOP 10 AssemblyName, SUM(Duration) AS ValueInMs, SUM(TestResults) AS TestResultCount FROM AssembliesByDuration WHERE Branch LIKE '"
                  + "$/branch1/sub1%" + "' GROUP BY AssemblyName ORDER BY SUM(Duration) DESC").ToList();    

我是否遗漏了某些内容，或者这只是Linq2SQL之后评估LIKE的问题？

Answer 1

在第一个查询中，您似乎缺少{0}周围的单引号。