如何在LINQ中连接两个表？

var result = from table1 in dataContext.Table1
             join table2 in dataContext.Table2
             on table1.KeyColumn equals table2.ForeignKeyColumn
             select new 
             {
                 Column1 = table1.Column1,
                 Column2 = table2.Column2
             };

var result = from table1 in dataContext.Table1
             join table2 in dataContext.Table2
             on table1.KeyColumn equals table2.ForeignKeyColumn
             select new 
             {
                 Column1 = table1.Column1,
                 Column2 = table2.Column2
             };

var result = from table1 in dataContext.Table1
             join table2 in dataContext.Table2
             on table1.KeyColumn equals table2.ForeignKeyColumn into joinedTable
             from item in joinedTable.DefaultIfEmpty()
             select new 
             {
                 Column1 = table1.Column1,
                 Column2 = item?.Column2
             };

var result = from table2 in dataContext.Table2
             join table1 in dataContext.Table1
             on table2.ForeignKeyColumn equals table1.KeyColumn into joinedTable
             from item in joinedTable.DefaultIfEmpty()
             select new 
             {
                 Column1 = item?.Column1,
                 Column2 = table2.Column2
             };