在T-SQL中，如何在子查询中引用表变量？

Question

我已经声明了一个表变量'@t'，并正确执行了'INSERT-INTO-SELECT'。 当我试图通过对每组行编号进行一些额外计算来查询表变量时，我在使用'@t'直接使用“必须声明变量”或使用'@t'的别名时出现“无效对象名称”错误”。请劝告。

SELECT 
    *,
    (SELECT COUNT(*) FROM "LTV" "COUNTER"
     WHERE 
        "COUNTER"."Collateral_ID" = "LTV"."Collateral_ID"
        AND
        "COUNTER"."m_il_no" = "LTV"."m_il_no"
        AND
        "COUNTER"."Ref_Key" <= "LTV"."Ref_Key"
     GROUP BY "COUNTER"."Collateral_ID", "COUNTER"."m_il_no"
    ) "MIL_IDX"

FROM @t AS LTV

Answer 1

使用：

SELECT x.*,
       y.num
  FROM @t x
  JOIN (SELECT t.collateral_id,
               t.m_il_no,
               COUNT(*) AS num
          FROM @t t
      GROUP BY t.collateral_id, t.m_il_no) y ON y.collateral_id = x.collateral_id
                                            AND y.m_il_no = x.m_il_no