I tried to get values from access data base with two where clause. This is the error that I got!
"Syntax error (missing operator) in query expression 'unit1<=34 and unit2>=34 where"'.
and this is my code:
OleDbConnection con = new OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=E:\\Work\\Office\\Electricity_Board_bill_calculator\\gk.accdb;");
con.Open();
OleDbCommand com5 = new OleDbCommand("select id from tblBillConfig where unit1<="
+ contot + " and unit2>=" + contot + " where group=3 ", con);
You have 'where' in 2 places of the SQL string. This is at least one reason for the error.
There are a couple of potential issues:
You can't have 2 where clauses. The second filter needs to be introduced with and`
Group is a reserved keyword, so and needs to be escaped. (This would be [group] in Sql Server. I'm not sure how to do this in MS Access)
You should also look at using parameters to bind variables. This addresses a bunch of issues, such as sql injection, and also improves performance as the parameterization may allow your RDBMS to cache the query plan.
So your query should look something like this:
var com5 = new OleDbCommand("select id from tblBillConfig " +
" where unit1<=? and unit2>= ? and [group]=3 ", con);
command.Parameters.Add("#p1", OleDbType.Integer).Value = 34;
command.Parameters.Add("#p2", OleDbType.Integer).Value = 34;
Related
This question already has answers here:
Single quote handling in a SQL string
(3 answers)
Closed 6 months ago.
I'm creating an application using Visual Studio 2019, with a connection to an MS Accsess database to add, get, modify and delete values inside the database.
I'm willing to insert a text that could contain a comma, for example : Gousse d'ail. But I know there will be a problem because the string has to be surrounded by commas. So I added a backslash before every extra comma inside the text I'm willing to insert.
The thing is a get an error message saying there is a syntax error, I believe it's because of the backslash.
Here is the message I get :
System.Data.OleDb.OleDbException (0x80040E14) : Syntax error (missing operator) in query expression " 'Gousse d\'ail', unite = 'kg', allergene = False, fournisseurID = 1 WHERE ingrédientID = 40; "
Everything works really well until there is comma.
Here is the method I use to insert into the database:
public void UpdateIngédient(int ingredientID, InfoIngredient ing)
{
string query = "UPDATE Ingrédients ";
query += "SET nom = '" + ing.Nom + "', unite = '" + ing.Unité + "', allergene = " + ing.Allergene + ", fournisseurID = " + ing.Fournisseur;
query += " WHERE ingredientID = " + ingredientID + ";";
OleDbCommand com = new OleDbCommand(query, oleConnection);
com.ExecuteNonQuery();
}
Your query is begging for SQL injection, as well as bugs exactly like the one you've encountered.
If you're doing any work with a SQL table (or OLE in your case) I strongly recommend spending some time to look into SQL injection to understand the risks.
It's very easy to defend against SQL injection and a rewrite of your code is shown below to protect against it.
void UpdateIngédient(int ingredientID, InfoIngredient ing)
{
string query = "UPDATE Ingrédients SET nom = #nom, unite = #unite, allergene = #allergene, fournisseurID = #fournisseur WHERE ingredientID = #ingredientID;";
OleDbCommand cmd = new OleDbCommand(query, oleConnection);
cmd.Parameters.Add(new OleDbParameter("#nom", ing.Nom));
cmd.Parameters.Add(new OleDbParameter("#unite", ing.Unité));
cmd.Parameters.Add(new OleDbParameter("#allergene", ing.Allergene));
cmd.Parameters.Add(new OleDbParameter("#fournisseur", ing.Fournisseur));
cmd.Parameters.Add(new OleDbParameter("#ingredientID", ingredientID));
OleDbCommand com = new OleDbCommand(query, oleConnection);
com.ExecuteNonQuery();
}
This should safeguard against "unexpected" characters in your strings such as the ' character
I am trying to write dynamic SQL statement, but i am getting exception syntax error,near LIKE operator where i used down in SQL statement
webmethod.asmx.cs
[WebMethod]
public void leavesRequest_data_to_hr()
{
List<leavesrecord> record = new List<leavesrecord>();
string Todaydate = DateTime.Now.ToString("dd-MM-yyyy");
string status = "Pending";
SqlConnection connection = new SqlConnection("Data Source = AMARNATHB; Initial Catalog = sample; Integrated Security = True");
SqlCommand cmd = new SqlCommand("select leaverequest.id,leaverequest.emp_id,leaverequest.date_inserted,leavesSignup.name,leaverequest.leaves_form,leaverequest.leaves_upto,leaverequest.leave_type,leaverequest.description,leaverequest.no_of_leaves from leaverequest inner join leavesSignup on leaverequest.emp_id = leavesSignup.emp_id where leaverequest.date_inserted like '%'"+Todaydate+"'%' and leaverequest.status='" + status + "'", connection);
cmd.CommandType = CommandType.Text;
connection.Open();
SqlDataReader idr = cmd.ExecuteReader();
while (idr.Read())
{
}
}
You have multiple issues with this logic:
" . . . leaverequest.date_inserted like '%'" + Todaydate + "'%' . . .
First, what it produces is:
leaverequest.date_inserted like '%'<some date value here>'%'
There are extra meaningless single quotes which are causing the syntax error.
More important than the syntax error are these two problems:
You are (presumably) treating a date column as if it were a string. Agghhh! like is for strings not dates.
You are passing in a value that munges your query string. This can make the code prone to SQL injection. It can make the code subject to hard-to-debug errors.
How about letting the database do the work?
" . . . convert(date, leaverequest.date_inserted) = convert(date, getdate()) . . .
I am assuming that you are using SQL Server. But similar constructs exist in all databases.
And, all other parameter values should be passed in as parameters, not by munging the query string.
I check my SQL Statement many times and it seems that my SQL Statement is Error. I don't why it doesn't work. My SQL Statement is correct and It resulted to this OleDBException "Syntax error in UPDATE statement.".
Here is the code
OleDbConnection CN = new OleDbConnection(mysql.CON.ConnectionString);
CN.Open();
cmd1 = new OleDbCommand("Update Mosque Set Name='" + txtNAME.Text + "', No='" + Convert.ToInt32(txtNO.Text) + "', place='" + txtPlace.Text + "', group='" + txtGroup.Text + "', description='" + txtdec.Text + "' where id='" + txtID.Text + "'", CN);
cmd1.ExecuteNonQuery();
CN.Close();
need help please to know what is the error here
I don't know what database are you using, but I am sure that GROUP is a reserved keyword in practically any existant SQL database. This word cannot be used without some kind of delimiter around it. The exact kind of delimiter depend on the database kind. What database are you using?
Said that, please do not use string concatenation to build sql commands, but use always a parameterized query. This will allow you to remove any possibilities of Sql Injection and avoid any syntax error if one or more of your input string contains a single quote somewhere
So, supposing you are using a MS Access Database (In Access also the word NO is a reserved keyword and the delimiters for reserved keywords are the square brakets) you could write something like this
string commandText = "Update Mosque Set Name=?, [No]=?, place=?, " +
"[Group]=?, description=? where id=?"
using(OleDbConnection CN = new OleDbConnection(mysql.CON.ConnectionString))
using(OleDbCommand cmd1 = new OleDbCommand(commandText, CN))
{
CN.Open();
cmd1.Parameters.AddWithValue("#p1",txtNAME.Text);
cmd1.Parameters.AddWithValue("#p2",Convert.ToInt32(txtNO.Text));
cmd1.Parameters.AddWithValue("#p3",txtPlace.Text);
cmd1.Parameters.AddWithValue("#p4",txtGroup.Text);
cmd1.Parameters.AddWithValue("#p5",txtdec.Text);
cmd1.Parameters.AddWithValue("#p6",txtID.Text);
cmd1.ExecuteNonQuery();
}
Instead for MySQL you have to use the backticks around the GROUP keyword
string commandText = "Update Mosque Set Name=?, No=?, place=?, " +
"`Group`=?, description=? where id=?"
Hard to tell without knowing the values of the texboxes, but I suspect that one of them has an apostrophe which is causing an invalid syntax.
I recommend using parameters instead:
cmd1 = new OleDbCommand("Update Mosque Set [Name]=#Name, [No]=#No, [place]=#Place, [group]=#Group, [description]=#Description WHERE id=#ID", CN);
cmd1.Parameters.AddWithValue("#Name",txtNAME.Text);
cmd1.Parameters.AddWithValue("#No",Convert.ToInt32(txtNO.Text));
// etc.
I have a problem trying to parameterize some "dynamic" SQL build in an existing C# class used by an ASP app. The environment is:
Win Server 2008
.NET 3.0
C#
DB2 9.x ([IBM][CLI Driver][DB2])
The existing code just concatenates the SQL with the param strings in a long SQL string - which is of course at risk for SQL injection. As is my practice whenever I see this, I tend to change the code to use parameters. But with this code I am failing. I have tried "#" and I have tried "?" - the latter is what I understand to be necessary for ODBC.
Here is a simplified code snippet (forgive me if I don't format it right - this is my first question) that I have compiled and run:
private DataSet test(String schemaName )
{
String sortField = "TABLE_NAME.COLUMN_NAME";
String sortDirection = "ASC";
OdbcConnection conn = new OdbcConnection();
DataSet ds = new DataSet();
string connStr = ConfigurationManager.AppSettings[schemaName] + dbUser;
try
{
conn.ConnectionString = connStr;
OdbcCommand cmd = new OdbcCommand("SELECT * FROM TABLE_NAME ORDER BY ? ? ");
cmd.Connection = conn;
cmd.CommandType = CommandType.Text;
cmd.Parameters.Add(sortField);
cmd.Parameters.Add(sortDirection);
logger.log("cmd SQL = \t" + cmd.CommandText );
OdbcDataAdapter da = new OdbcDataAdapter(cmd);
da.Fill(ds);
return ds;
}
catch (Exception ex)
{
ex.Data.Add("Location:", "test()");
ex.Data.Add("Connection", conn.ConnectionString);
logger.logException(ex);
throw ex;
}
finally
{
conn.Close();
}
}
Log printout:
cmd SQL = SELECT * FROM TABLE_NAME ORDER BY ? ?
Where TABLE_NAME is of course the table I am querying.
What I get in return is this (some proprietary info removed:
EXCEPTION occured at 4/26/2012 12:29:41 PM ERROR [42601] [IBM][CLI
Driver][DB2] SQL0104N An unexpected token "?" was found following "".
Expected tokens may include: "MICROSECONDS MICROSECOND SECONDS SECOND
MINUTES MINUTE HOURS". SQLSTATE=42601
at System.Data.Odbc.OdbcConnection.HandleError(OdbcHandle hrHandle, RetCode retcode)Connection Driver={IBM DB2 ODBC DRIVER};
.....
Changing this to a stored proc is not allowed.
Upgrading to a later version of .NET is not allowed.
Changing/upgrading the ODBC driver is not allowed.
What I am seeing indicates to me that the "?" parameter is not being replaced.
I have tried AddWithValue() and I have tried Add(OdbcType.VarChar).Value = sortField (or something to that effect).
I am kind of at my whit's end - all of the googling and searching here indicates to me that the code above should work, but so far I have not been able to get the parameters in the SQL substituted with the variables.
Thanks in advance.
The reason the ? is an unexpected token is because you are using it in the ORDER BY clause (which I don't think is allowed).
The reason to use parameters is to mitigate the risks of user input. When building your query, if the ORDER BY field and direction are not coming via user input, you are safe in building the query with concatenation.
Only use the ? in the WHERE clause:
OdbcCommand cmd = new OdbcCommand("SELECT * FROM TABLE_NAME WHERE ID = ? ORDER BY " + sortField + " " + sortDirection);
I have an Access Db with C# and I am doing a concatenation in sql query aftere where clause but I am getting the following error
"Syntax error (missing operator) in query expression"
My code is below
cmd.CommandText = "Select * from TEMP1 WHERE EMAIL=" + GlobalData.Email;
Please tell me what is causing the error and what the correct syntax is for concatenation.
You'd better use SqlParameter (more secure):
SqlCommand cmd = new SqlCommand("SELECT * FROM Temp1 WHERE Email LIKE #email")
cmd.Parameters.Add(new SqlParameter("email", GlobalData.Email));
To answer to the original question:
Using direct concatenation, without string delimiter, your query become:
SELECT * FROM Temp1 WHERE Email LIKE email#email.com
instead of
SELECT * FROM Temp1 WHERE Email LIKE 'email#email.com'
I think your your problem is missing quotes. Try this:
cmd.CommandText = "Select * from TEMP1 WHERE EMAIL='" + GlobalData.Email + "'";
But that method can lead to SQL injection if you don't validate the email. Although there is nothing wrong with the above code, if data is validated, I do prefer to use SQL Parameters:
SqlCommand cmd = new SqlCommand( "SELECT * FROM Temp1 WHERE Email = #Email" )
cmd.Parameters.Add( new SqlParameter( "Email" , GlobalData.Email ) );
Try using Parameterised queries instead. It's usually the norm when working with SQL queries, for security reasons as well as readability.
You don't have any apostrophes around the string literal, so your query will end up like:
Select * from TEMP1 WHERE EMAIL=someone#somesite.com
This will of course cause a syntax error. You need the apostrophes around the string:
cmd.CommandText = "Select * from TEMP1 WHERE EMAIL='" + Replace(GlobalData.Email, "'", "''") + "'";
However, encoding strings correctly is not trivial. (The above method works for Access and Microsoft SQL Server, but other databases needs other methods.) You should rather use parametrised queries:
cmd.CommandText = "Select * from TEMP1 WHERE EMAIL=#email";
Then you add a parameter to the command object, for example:
cmp.Parameters.Add("#email", DbType.VarChar, 300).Value = GlobalData.Email;
Try something like below
cmd.CommandText = "Select * from TEMP1 WHERE EMAIL='" + GlobalData.Email + "'";
i'm not sure about the error, but you should try it like that
cmd.CommandText = string.Format("SELECT * FROM TEMP1 WHERE EMAIL='{0}'", GlobalData.Email);
That way you don't need to mess with ugly concatination that btw, takes alot of memory usage.