Question

我想检查哪些用户在数据库中拥有最多记录。因此每个用户都有一个特定的Id，并且该Id在几个表中用作参考。

有几个表包含一个UserId列，如表Exams，Answers，Questions，Classes等。是否可以在所有这些表中计算具有特定UserId的所有记录？

Answer 1

我会这样做：

var inp = $("#txt");
// where #txt is the id of the textbox

$(".table-cell-text").keyup(function (event) {
if (event.keyCode == 13) {
    if (inp.val().length > 0) {
      $('#myTable tr:last').replaceWith('<tr class="table-row"><td class="table-cell">' + inp.val() + '</td>' +
        '<td class="table-cell">' +
        '<td></td>' +
        '</td>' +
        '<td class="table-cell">' +
        '</td></tr>');
    }
}

});

如果您只想要计数，则不需要表名，只是您想知道来源的情况。

Answer 2

;with cte as (
select rowsCount = count(*) from A where UserId = 1
union all
select rowsCount = count(*) from B where UserId = 1
union all
select rowsCount = count(*) from C where UserId = 1
)
select sum(rowsCount) from cte

Answer 3

试试这个，

SELECT Count(E.ID) + Count(A.ID) + Count(Q.ID) + Count(C.ID) AS SumofAllCount
FROM dbo.Exams E
LEFT JOIN dbo.Answers A ON A.UserId = E.UserId
LEFT JOIN dbo.Questions Q ON Q.UserId = E.UserId
LEFT JOIN dbo.Classes C ON C.UserId = E.UserId
WHERE E.UserId = @YouruserID
GROUP BY E.UserId

如何获取数据库中特定ID的记录数量？

3 个答案: