如何从表达式列更新金额列

Question

这是我的问题：如何将 Amount 列从级别 1 更新到级别 6？

id Code  amount formula                 level
-----------------------------------------------
1   A10 0.00    A07                     5
2   A02 0.00    (A01+A04)*A05           2
3   A03 0.00    A02+A04                 3
4   A04 40.00                           1
5   A05 50.00                           1
6   A06 0.00    A03+A01                 4
7   A0  0.00    A04+A07+A10+A01+A02+A03 6
8   A01 20.00                           1
9   A07 0.00    (A03)                   4
10  A08 0.00    (A01)                   2

Answer 1

我可能做了很多假设，这些假设对于您的目的来说不够通用，更不用说这完全未经测试了。但也许这是您试验的起点。

declare @id int;
declare @level int = 2;
declare @code varchar(8);
declare @amt decimal(10, 2)
while @level <= (select max(id) from T)
begin
    set @id = 1;
    while @id <= (select max(id) from T)
    begin
        set @code = null; set @amount = null;
        select @code = Code, @amount = amount from T where id = @id and level = @level - 1;
        if @code is not null update T set formula = replace(formula, @code, '(' + cast(amount as varchar(16)) + ')'
        set @id = @id + 1;
    end
    set @level = @level + 1;
end

set @id = 1;
while @d <= (select max(id) from T)
begin
    -- use dynamic sql to evaluate each of the expression (assuming they're valid)
    declare @sql nvarchar(max) = N'declare @f decimal(10, 2); select @f = ' +
        (select formula from T where id = @id);
    sp_executesql @sql, 'decimal(10, 2)', @amt output;
    update T set amount = @amt where id = @id;
    set @id = @id + 1;
end

如何从表达式列更新金额列

How to update Amount column from an expression column

sql

sql-server

expression

sql-server-2012