如何在文本框C＃代码中进行操作 [英] How I can make my operation in a textbox, C# code

问题描述

我想在我的表中计算一个列的总数，条件如下：当我用（识别）搜索时，我有totale_price：



< br $>




这是我的Sqlrêquete

SELECT SUM（价格）AS total_Price from nom_table where visible ='0' GROUP BY identify ='..';



我尝试过：



在textBox中进行操作，C＃代码

i want to calculate a totale of a column in my table, with this condition: when i search with (identif) i have had the totale_price :




this's my Sql rêquete
SELECT SUM(Price) AS total_Price from nom_table where visible = '0' GROUP BY identif='..';

What I have tried:

make my operation in a textBox, C# code

推荐答案

SQL GROUP BY不包含条件：它是列列表（通常只有一列，列表在添加更多列时扩展组的数量，而不是细化它。）

所以这可能有用：

SQL GROUP BY does not include conditions: it's a column list (and normally just one column, the list expands the number of groups as you add more columns, not refines it).
So this might work:

SELECT SUM(Price) AS total_Price FROM nom_table WHERE visible = '0' GROUP BY identif

但请记住GROUP BY将为每个不同的行创建单独的行分组列中的值：如果您在整个表的总数之后，则根本不使用GROUP BY：

But do remember that GROUP BY will create separate rows for each distinct value in the grouping column: if you are after a total for a whole table, then don't use GROUP BY at all:

SELECT SUM(Price) AS total_Price FROM nom_table WHERE visible = '0' AND identif = '..'

可能是更好，因为它为所有匹配的行返回单个值。

Might be better as it returns a single value for all matching rows.

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