How to use Like keyword which is inside of combobox

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I have a grid view which include a row that contain
1. Combobox for column selection
<big>2. Combobx for searching method (=, like, <, <>, >)</big>
3. Text box for search (what to search)
4. Combobox for operator (AND/OR)

look carefully this code fragment

C#

if (dataGridView1.RowCount > 1) //When DataGridview Contain MOre then 1 row
                {
                    if (Datarow.Cells[0].Value != null && Datarow.Cells[1].Value != null
                    && Datarow.Cells[2].Value != null && Datarow.Cells[3].Value != null)
                    {
WhereClause += Datarow.Cells[0].Value.ToString() + "  " + Datarow.Cells[1].Value.ToString() + " " + Datarow.Cells[2].Value.ToString()+ " " + Datarow.Cells[3].Value.ToString()+ " ";
                        SearchQuery =  WhereClause;
                    }

I am using this to Form a Where Clause. but Gridview's 2nd column which inside Combobox # 2 and it contain (=, like, <, <>, >) which is really problem form me

C#

Datarow.Cells[1].Value.ToString()

this contain =, <>, <, >, and most important like
now how can i use like key word. The above fragment of code working fine with =, <>, <,> but what for Like i want to use with % but i dont know how to it

Posted 4-Nov-13 6:54am

Muhamad Faizan Khan

Updated 4-Nov-13 21:20pm

coded007

v4

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Tadit Dash (ତଡିତ୍ କୁମାର ଦାଶ) 4-Nov-13 13:45pm

Provide more info. Is it windows form? What exactly is the scenario?

Muhamad Faizan Khan 4-Nov-13 13:50pm

yes window form

2 solutions

Solution 2

You'll have to treat it specially. Like:

C#

const string LikeMethodName = 'like';
WhereClause += Datarow.Cells[0].Value.ToString() + "  ";
string method = Datarow.Cells[1].Value.ToString();
if (method.Equals(LikeMethodName, StringComparison.OrdinalIgnoreCase))
{
  WhereClause += "like '%" + Datarow.Cells[2].Value.ToString() + "%' ";
}
else
{
  WhereClause += method + " " + Datarow.Cells[2].Value.ToString() + " ";
}
WhereClause += Datarow.Cells[3].Value.ToString() + " ";
SearchQuery = WhereClause;

Assuming that all of the values you are using to construct the query are selections from lists that you define, then this is OK. If any value going into the query is "typed-in" by the user, then this is very vulnerable to SQL injection attacks[^].

In any case, instead of repeated string concatenation, I suggest using System.Text.StringBuilder for assembling a string from multiple pieces.

Posted 4-Nov-13 7:49am

Matt T Heffron

Updated 5-Nov-13 6:58am

v3

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Tadit Dash (ତଡିତ୍ କୁମାର ଦାଶ) · Accepted Answer · 2013-11-04T07:41:00

Solution 1

Check for "like" in a "if" clause something like below...

C#

if(Datarow.Cells[1].Value.ToString().ToLower().Equals("like"))
{
    WhereClause += Datarow.Cells[0].Value.ToString() + "  " + "like '%" + Datarow.Cells[2].Value.ToString()+ "%' " + Datarow.Cells[3].Value.ToString()+ " ";
}
else
{
    WhereClause += Datarow.Cells[0].Value.ToString() + "  " + Datarow.Cells[1].Value.ToString() + " " + Datarow.Cells[2].Value.ToString()+ " " + Datarow.Cells[3].Value.ToString()+ " ";
}

Posted 4-Nov-13 7:41am

Tadit Dash (ତଡିତ୍ କୁମାର ଦାଶ)

Updated 5-Nov-13 8:13am

v5

Comments

Muhamad Faizan Khan 4-Nov-13 14:02pm

again if.. will this work sure.?

Tadit Dash (ତଡିତ୍ କୁମାର ଦାଶ) 4-Nov-13 14:09pm

Try and let me know, it should work. :)

Muhamad Faizan Khan 4-Nov-13 14:26pm

i check it but it showing me an error incorrect synatx
if (Datarow.Cells[0].Value != null && Datarow.Cells[1].Value != null && Datarow.Cells[2].Value != null)//&& Datarow.Cells[3].Value != null)
{
if(Datarow.Cells[1].Value.ToString().ToLower().Equals("like"))
{
WhereClause += Datarow.Cells[0].Value.ToString() + " "+ Datarow.Cells[1].Value.ToString() + " %" + Datarow.Cells[2].Value.ToString() + "% ";
}
else
{
WhereClause += Datarow.Cells[0].Value.ToString() + " " + Datarow.Cells[1].Value.ToString() + " %" + Datarow.Cells[2].Value.ToString() + "% ";
//WhereClause += Datarow.Cells[0].Value.ToString() + " " + Datarow.Cells[1].Value.ToString() + " " + Datarow.Cells[2].Value.ToString() + " ";
}
SearchQuery = WhereClause;
}

Tadit Dash (ତଡିତ୍ କୁମାର ଦାଶ) 4-Nov-13 14:29pm

Where is that syntax error exactly?

Muhamad Faizan Khan 4-Nov-13 14:34pm

I have got it single quotation were missing.

Tadit Dash (ତଡିତ୍ କୁମାର ଦାଶ) 4-Nov-13 22:31pm

Glad to hear that. Well done. Please accept the answer. :)

Muhamad Faizan Khan 4-Nov-13 14:22pm

my program doing false this condition, i dont know. why? if(Datarow.Cells[1].Value.ToString().ToLower().Equals("like"))

Tadit Dash (ତଡିତ୍ କୁମାର ଦାଶ) 4-Nov-13 14:27pm

While debugging, check what is the value of Datarow.Cells[1].Value.ToString()?

Tadit Dash (ତଡିତ୍ କୁମାର ଦାଶ) 4-Nov-13 14:33pm

You should have "like %". Only "%" will not work.

Muhamad Faizan Khan 4-Nov-13 14:47pm

sorry there were my mistake in like keyword please update your answer with single quotation as well i.e., i am accept it

Tadit Dash (ତଡିତ୍ କୁମାର ଦାଶ) 5-Nov-13 14:14pm

Updated my answer. You can accept now.

Thanks,
Tadit.