Question

我在RosterSummaryData_Subject_Local实体上执行linq查询时收到错误。我似乎无法弄清楚出了什么问题或解决方案。

无法创建类型为“System.Int32 []”的null常量值。只要支持实体类型，枚举类型或基元类型这个背景。

我的代码第一个实体上下文的LINQ查询：

var subjLocal = customerContext.RosterSummaryData_Subject_Local.Where(s => 
    (s.fkRosterSetID == 0) &&
    (statsInfo.TestInstanceIDsList.Contains(s.fkTestInstanceID)) &&
    (s.fkTestTypeID == statsInfo.TestTypeID) &&
    (statsInfo.SchoolYearIDsList.Contains(s.fkSchoolYearID)) &&
    (s.fkRosterTypeID == 1) &&
    (s.fkSchoolID == 0) &&
    (s.fkDepartmentID == 1) &&
    (s.fkCourseID == 1) &&
    (s.fkPeriodID == 1) &&
    (statsInfo.DemoCatIDsList.Contains(s.fkDemoCommonCategoryID)) &&
    (statsInfo.DemoCodeIDsList.Contains(s.fkDemoCommonCodeID)) &&
    (statsInfo.TestSubjectIDsList.Contains(s.fkTest_SubjectID)));

Answer 1

听起来您的Int32[]类型之一是null。在访问.Contains方法之前，请尝试添加检查：

var subjLocal = customerContext.RosterSummaryData_Subject_Local.Where(s => 
    (s.fkRosterSetID == 0) &&
    (statsInfo.TestInstanceIDsList != null &&
        statsInfo.TestInstanceIDsList.Contains(s.fkTestInstanceID)) &&
    (s.fkTestTypeID == statsInfo.TestTypeID) &&
    (statsInfo.SchoolYearIDsList != null &&
        statsInfo.SchoolYearIDsList.Contains(s.fkSchoolYearID)) &&
    (s.fkRosterTypeID == 1) &&
    (s.fkSchoolID == 0) &&
    (s.fkDepartmentID == 1) &&
    (s.fkCourseID == 1) &&
    (s.fkPeriodID == 1) &&
    (statsInfo.DemoCatIDsList != null &&
        statsInfo.DemoCatIDsList.Contains(s.fkDemoCommonCategoryID)) &&
    (statsInfo.DemoCodeIDsList != null &&
        statsInfo.DemoCodeIDsList.Contains(s.fkDemoCommonCodeID)) &&
    (statsInfo.TestSubjectIDsList != null &&
        statsInfo.TestSubjectIDsList.Contains(s.fkTest_SubjectID)));

或者，如果它们为空是好的（我认为它不是，但以防万一），您可以更改上述检查以遵循这种模式：

(statsInfo.DemoCatIDsList == null ||
    statsInfo.DemoCatIDsList.Contains(s.fkDemoCommonCategoryID)) &&

LINQ to entity错误：“无法创建类型''System.Int32 []”的空常量值。只有实体类型，枚举类型

1 个答案: