Query for a combobox and textbox to search within a datagrid

Baka Musky

9y903

Hey everyone,

I currently nearly finished a simple application, but my query doesnt work. I have a combobox and a textbox. By selecting a column name from the combobox, I want to be able to search in the textbox within that column. Anyone that can fix this query? I've been trying alot but havent had any succes yet.

SqlCommand command = new SqlCommand("SELECT * FROM dbo.Kwartaal " +

"WHERE '" + searchField + "' LIKE '% " + txtSearch.Text + "%' ", con);

Edit: searchField is my string that gets filled by selecting the column. txtSearch is the textbox obviously.

6 Replies

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Amit Gupta9y ago
Accepted answer
Like keywords will work on almost all types of datatypes whether it is a number, letter, date etc.

One thing I noticed in your code that your column contains space between naming, so it will not work as with current query, yoi have to use square brackets, now your final query should look like this
SqlCommand command = new SqlCommand(string.Format("SELECT * FROM dbo.Kwartaal WHERE [{0}] Like '%{1}%'", searchField, txtSearch.Text), con);
Baka Musky9y ago
I see.. I tried the query now and still doesn't find the ID's. All my columns has been changed and has no spaces in them whatsoever. Also, if I press the search button twice, the 2nd time I get an exception, it says: The child list for field DS1 cannot be created, I've googld this and tried some things out but without any luck.
Baka Musky9y ago
Dam, Im so thankful!!

It works now, but only with columns that has letters in it, if there are numbers and I search for an ID it doesnt work. Any fix on that?
Amit Gupta9y ago
Ah!! That was missed .. the error happens because you had mistakenly put the closing braket after the connection object. It sould be
SqlCommand command = new SqlCommand(string.Format("SELECT * FROM dbo.Kwartaal WHERE {0} Like '%{1}%'", searchField, txtSearch.Text), con);
Baka Musky9y ago
Thanks for replying Amit Gupta,

I see that my query is a whole lot different than yours, and understand what was wrong now. Only problem with the query u gave me is that it missed a " ) " at the end. But when I run the program now, I get an exception:

System.InvalidOperationException: Fill: SelectCommand.Connection property has not been initialized.

My entire code: https://hastebin.com/qirapefidi.cs
Amit Gupta9y ago
Hey

Don't put single quote in your column name and avoid using concated string to build query, it will always make confusion.
SqlCommand command = new SqlCommand(string.Format("SELECT * FROM dbo.Kwartaal WHERE {0} Like '%{1}%'", searchField, txtSearch.Text, con);