where clause not working when combobox select data

Question

1.00/5 (1 vote)

See more:

hi
"where" clause does not working.combobox not retrieve data.

Working

string Query ="SELECT txIT FROM It ";

Not working

string Query ="SELECT txIT FROM It WHERE cmboItem ='"+cmboItem.SelectedValue+"'";

Posted 8-Sep-13 22:18pm

indiancodinglove

Add a Solution

Comments

Thanks7872 9-Sep-13 5:06am

It would be better if you elaborate your question on what do you mean by "where" clause does not working.combobox not retrieve data.It also important to note here,care must be taken while binding dropdown on postback.

3 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

phil.o · Answer 1 · 2013-09-08T22:39:00

It is never a good idea to construct a SQL query by concatenating string values from user inputs.
Better use parameterized queries.

As to your problem: you should check first that

cmboItem.SelectedValue

returns the actual data you need ; maybe

cmboItem.SelectedText

would fit best.

But finally, when you have determined which one of these properties is the right one, you should use a parameterized query:

C#

using (SqlConnection con = new SqlConnection(yourConnectionString)) {
   string sql = "SELECT txIT FROM It WHERE cmboItem = @value;";
   SqlCommand cmd = new SqlCommand(sql, con);
   cmd.Parameters.AddWithValue("value", cmboItem.SelectedText);
   con.Open();
   // Then execute the query, get your results, etc.
}

V.Lorz · Answer 2 · 2013-09-08T22:57:00

Check your database for the existance of the items you're willing to select and try the query sentence manually so you can ensure yourself that the query generation code works properly.

Combined with the parameterized query generation provided by phil.o[^] here where clause not working when combobox select data[^] in his previous solution, alter his query and replace:

cmd.Parameters.AddWithValue("value", cmboItem.SelectedText);

by (1):

cmd.Parameters.AddWithValue("value", cmboItem.Text);

or by (2):

cmd.Parameters.AddWithValue("value", cmboItem.SelectedItem.ToString());

See the comment I placed in his solution.
Depending on the databindings you made to populate the combobox items list you could even need to do it in some other ways.

Uknownymous · Answer 3 · 2013-09-08T22:25:00

Solution 1

try this:

C#

string Query ="SELECT txIT FROM It WHERE cmboItem ='" & cmboItem.SelectedText & "'";

Posted 8-Sep-13 22:25pm

Uknownymous

Comments

indiancodinglove 9-Sep-13 4:38am

Show an Error

Operator '&' cannot be applied to operands of type 'string' and 'string'

Uknownymous 9-Sep-13 4:48am

oh .. im sorry i forgot you are using C#. just replace `&` to `+` .

V.Lorz 9-Sep-13 4:43am

Visual Basic string concatenation operator (&)?????