using MongoDB.Bson; using SqlSugar.MongoDb; using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace MongoDbTest { internal class QueryLeftJoin { internal static void Init() { var db = DbHelper.GetNewDb(); db.DbMaintenance.TruncateTable(); // 添加学校数据 var school = new School { Name = "TestSchool" }; var ids=db.Insertable(school).ExecuteReturnPkList(); // 添加学生数据,SchoolId 关联学校 var student = new Student { Name = "TestStudent", SchoolId = ids.Last() }; db.Insertable(student).ExecuteCommand(); // 添加学生数据,SchoolId 关联学校并且没有学校 var student2 = new Student { Name = "TestStudentNoSchool", SchoolId = ObjectId.GenerateNewId().ToString() }; db.Insertable(student2).ExecuteCommand(); if (db.Queryable().First(it => it.SchoolId == ids.Last()).Name != "TestStudent") Cases.ThrowUnitError(); db.Updateable(db.Queryable().First(it => it.SchoolId == ids.Last())).ExecuteCommand(); if (db.Queryable().First(it => it.SchoolId == ids.Last()).Name != "TestStudent") Cases.ThrowUnitError(); var adoTest= db.Ado.GetDataTable(@"aggregate UnitStudent123131 [ { $lookup: { from: ""UnitSchool123131"", localField: ""SchoolId"", foreignField: ""_id"", as: ""y"" } }, { $unwind: { path: ""$y"", preserveNullAndEmptyArrays: true } }, { $project: { _id: 0, StudentName: ""$Name"", SchoolName: { $ifNull: [""$y.Name"", null] } } } ]"); var list = db.Queryable() .LeftJoin((x, y) => x.SchoolId == y.Id) .Select((x, y) => new { StudentName = x.Name, SchoolName = y.Name }).ToList(); if (list.Count != 3) Cases.ThrowUnitError(); if (list.Any(s=>s.SchoolName== "TestSchool") ==false) Cases.ThrowUnitError(); if (list.Any(s => s.StudentName == "jack") == false) Cases.ThrowUnitError(); var list2 = db.Queryable() .InnerJoin((x, y) => x.SchoolId == y.Id) .Select((x, y) => new { StudentName = x.Name, SchoolName = y.Name }).ToList(); if (list2.Count != 1) Cases.ThrowUnitError(); if (list2.Any(s => s.SchoolName == "TestSchool") == false) Cases.ThrowUnitError(); var list3 = db.Queryable() .LeftJoin((x, y) => x.SchoolId == y.Id) .Where((x,y)=>x.Name=="jack") .Select((x, y) => new { StudentName = x.Name, SchoolName = y.Name }).ToList(); if (list3.Any(s => s.SchoolName ==null&&s.StudentName=="jack")==false) Cases.ThrowUnitError(); var list4 = db.Queryable() .LeftJoin((x, y) => x.SchoolId == y.Id) .Where((x, y) => x.Name == "jack"||y.Name== "TestSchool") .Select((x, y) => new { StudentName = x.Name, SchoolName = y.Name }).ToList(); if(list4.Count!=2) Cases.ThrowUnitError(); if (list4.Any(s=>s.SchoolName== "TestSchool") ==false) Cases.ThrowUnitError(); if (list4.Any(s => s.SchoolName == null||s.StudentName== "jack") == false) Cases.ThrowUnitError(); db.Insertable(new Student { Name = "A", SchoolId = ids.Last() }).ExecuteCommand(); var list5 = db.Queryable() .LeftJoin((x, y) => x.SchoolId == y.Id) .OrderByDescending((x,y)=>x.Name) .Select((x, y) => new { StudentName = x.Name, SchoolName = y.Name }).ToList(); if (list5.Count != 4) Cases.ThrowUnitError(); if (list5.Last().StudentName!= "A") Cases.ThrowUnitError(); if (list5.First().StudentName != "jack") Cases.ThrowUnitError(); var list6 = db.Queryable() .LeftJoin((x, y) => x.SchoolId == y.Id) .OrderBy((x, y) => x.Name) .Select((x, y) => new { StudentName = x.Name, SchoolName = y.Name }).ToList(); if (list6.Count != 4) Cases.ThrowUnitError(); if (list6.Last().StudentName != "jack") Cases.ThrowUnitError(); if (list6.First().StudentName != "A") Cases.ThrowUnitError(); } [SqlSugar.SugarTable("UnitStudent123131")] public class Student : MongoDbBase { public string Name { get; set; } [SqlSugar.SugarColumn(ColumnDataType =nameof(ObjectId))] public string SchoolId { get; set; } } [SqlSugar.SugarTable("UnitSchool123131")] public class School : MongoDbBase { public string Name { get; set; } } } }