使用选择查询数据 MS Access 更新特定表列

Question

我正在使用 MS Access 2019 并且有两个表：

• table_a (id_a, number_a)
• table_b (id_b, name_b)

此UPDATE语句不起作用：

UPDATE table_a
SET number_a = (SELECT COUNT(*) FROM table_b WHERE id_b IN (1,3) AND name_b=@name) 
WHERE id_a=1;

错误

操作必须使用可更新的查询

Answer 1

UPDATE table_a 
SET table_a.number_a = DCount("*","table_b","id_b IN (1,3) AND name_b=@name")
WHERE table_a.id_a=1;

或者

UPDATE table_a 
SET table_a.number_a = DCount("*","table_b","id_b IN (1,3) AND name_b=" & @name)
WHERE table_a.id_a=1;

取决于什么是@name ，它在哪里定义以及如何用它的值替换。

Answer 2

你为什么不捕捉价值然后像下面这样分配它

DECLARE @COUNT_B INT
SELECT @COUNT_B = COUNT(*) FROM table_b WHERE id_b IN (1,3) GROUP BY id_b

UPDATE table_a
SET number_a = @COUNT_B
WHERE id_a=1;