从子句中选择SQL [英] SQL SELECT FROM WHERE CLAUSE

问题描述

我在sql select from where子句中使用可变数据元素找不到工作示例.

例如，从表中选择*，而fielda ="123"不是我想要的.

字符串myselection ="123";

从表中选择*，其中fielda = myselection是我想要的

我正在使用C#和Visual Studio 2008和SQL Server2008.

谢谢.

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I can not find a WORKING example using a variable data element in the sql select from where clause.

example select * from table where fielda = "123" is not what I want to do.

string myselection = "123";

select * from table where fielda = myselection is what I want

I am using C# and visual studio 2008 and sql server 2008.

thanks.

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[Modified: First, I added the C# tag...second, I removed your email...if someone posts a response to this, you''ll get an email...posting your email only servers to help spammers know where to send stuff]

推荐答案

一种更简单的方法看起来像您所需要的:

One simpler method for it looks like you need:

SET @mySelection = '123'
SELECT * FROM myTable WHERE fielda = @mySelection

好...

ok...so do

string SQL = "SELECT * FROM table WHERE fielda='" & myselection & "';"

或

or

SqlCommand nonqueryCommand = thisConnection.CreateCommand();

nonqueryCommand.CommandText = "SELECT * FROM table WHERE fielda=@fielda;";
nonqueryCommand.Parameters.Add("@fielda", SqlDbType.VarChar, 30);

[更新:抱歉，我错过了添加中的参数.它应该显示为

[Updated: sorry, I missed a parameter in the Add. It should read

nonqueryCommand.Parameters.Add("@fielda",SqlDbType.Int).Value = 123;
//or something similar

什么是低票?]

And what''s with the downvoting?]

使用此

字符串SQL = @"SELECT * FROM table WHERE fielda =""+ myselection +"''"


这项艰辛的工作....

Use this

string SQL = @"SELECT * FROM table WHERE fielda=''" + myselection + "''"


This sould work....

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