ExecuteNonQuery() doesn't work - c#

Every time I try to run my code, I get this exception:
An unhandled exception of type 'System.Data.SqlClient.SqlException'
occurred in System.Data.dll
Additional information: Incorrect syntax near ')'.
Tried multiple workarounds, but I never get past the ExectueNonQuery line. Can someone tell me what's wrong with it?
private void button1_Click(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection(#"Data Source=CHARLIE-PC\MSSQLSERVER1;Initial Catalog=Tema;Integrated Security=True;");
con.Open();
SqlCommand cmd = new SqlCommand("INSERT INTO Fisier (idFisier, Nume, idFolder) VALUES ('"+idFis.Text+ "','"+ numeFis.Text + "','" +idFoldFis.Text +"',)", con);
cmd.ExecuteNonQuery();
con.Close();
}

While the other questions state the root problem, your trailing comma, you really must do better about your queries. Do not glue your query together like that, use parameters instead. If you do not you are opening yourself to huge security problems. Also you really must put the connection in a using statement so when a error does happen the connection will still be closed.
private void button1_Click(object sender, EventArgs e)
{
using(SqlConnection con = new SqlConnection(#"Data Source=CHARLIE-PC\MSSQLSERVER1;Initial Catalog=Tema;Integrated Security=True;"))
{
con.Open();
SqlCommand cmd = new SqlCommand("INSERT INTO Fisier (idFisier, Nume, idFolder) VALUES (#idFis,#numeFis,#idFoldFis)",con);
cmd.Parameters.Add("#idFis", SqlDbType.NVarChar, -1).Value = idFis.Text;
cmd.Parameters.Add("#numeFis", SqlDbType.NVarChar, -1).Value = numeFis.Text;
cmd.Parameters.Add("#idFoldFis", SqlDbType.NVarChar, -1).Value = idFoldFis.Text;
cmd.ExecuteNonQuery();
}
}

The comma is your problem, but I would recommend a few other changes at least before moving on:
Don't embed your connection strings into each db connection request. Use app.config/web.config or anything else :)
Ensure your connections are commands are properly disposed of
Parameterize any SQL queries to prevent injection attacks
Abstract database commands into separate business layer
1. Utilize an "app.config" for connection strings
There are many docs out there on keeping a connection string secure, but at a minimum, don't embed straight into each of your connection code.
Add an "app.config" to your client project (or utilize the web.config of web projects). At a minimum, this looks like this:
<configuration>
<appSettings>
<add key="db" value="Data Source=CHARLIE-PC\MSSQLSERVER1;Initial Catalog=Tema;Integrated Security=True;" />
</appSettings>
</configuration>
Then add a reference to "System.Configuration" to your project, and you can reference it like this in your code:
var con = new SqlConnection(ConfigurationManager.AppSettings["db"]);
2. Ensure your connections ard commands are properly disposed
Wrap connections and commands in using. Here is an example:
using (var con = new SqlConnection(ConfigurationManager.AppSettings["db"]))
{
con.Open();
var sql = "/* My command here */";
using (var cmd = new SqlCommand(sql, con))
{
// SQL execution here
}
} // Closing is now handled for you (even if errors occur)
3. Parameterize any SQL queries to prevent injection attacks
Concatenating strings are very dangerous for SQL commands (just google "SQL Injection"). This is how to protect yourself.
using (var con = new SqlConnection(ConfigurationManager.AppSettings["db"]))
{
con.Open();
var sql = "INSERT INTO Fisier (idFisier, Nume, idFolder) VALUES (#idFisier, #nume, #idFolder)";
using (var cmd = new SqlCommand(sql, con))
{
cmd.Parameters.Add("#idFisier", SqlDbType.VarChar).Value = idFis.Text;
cmd.Parameters.Add("#nume", SqlDbType.VarChar).Value = numeFis.Text;
cmd.Parameters.Add("#idFolder", SqlDbType.VarChar).Value = idFoldFis.Text;
cmd.ExecuteNonQuery();
}
} // Closing is now handled for you (even if errors occur)
4. Abstract database commands into separate business layer
It is usually best practice and will save you many headaches by writing separate classes (even class library) as your business layer that only contain your data commands. Then your UI would only handle calling the business layer methods.
If your database ever changes or you need to do similar functionality in other parts of your UI, it won't be very fun updating the same query all over your UI as opposed to just updating a single spot in your business layer.

Make SQL being readable and parametrized and you'll find the routine easy to implement:
// Extract a method (or even a class): do not mix UI and business logic/storage
// Just RDBMS logic: no UI controls or something at all
private static void CoreInsertFisier(string idFisier, nume, idFolder) {
// Do not hardcode the connection string, but read it (from settings)
// wrap IDisposable into using
using (SqlConnection con = new SqlConnection(ConnectionStringHere)) {
con.Open();
// Make sql readable (use verbatim strings #"...")
// Make sql parameterized
string sql =
#"INSERT INTO Fisier (
idFisier,
Nume,
idFolder)
VALUES (
#prm_idFisier,
#prm_Nume,
#prm_idFolder)";
// wrap IDisposable into using
using (SqlCommand cmd = new SqlCommand(sql, con)) {
// Parameters.Add(...) is a better choice, but you have to know fields' types
cmd.Parameters.AddWithValue("#prm_idFisier", idFisier);
cmd.Parameters.AddWithValue("#prm_Nume", nume);
cmd.Parameters.AddWithValue("#prm_idFolder", idFolder);
cmd.ExecuteNonQuery();
}
}
}
...
private void button1_Click(object sender, EventArgs e) {
// UI: just one call - please insert these three textbox into db
CoreInsertFisier(idFis.Text, numeFis.Text, idFoldFis.Text);
}

You have an extra trailing comma:
private void button1_Click(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection(#"Data Source=CHARLIE-PC\MSSQLSERVER1;Initial Catalog=Tema;Integrated Security=True;");
con.Open();
SqlCommand cmd = new SqlCommand("INSERT INTO Fisier (idFisier, Nume, idFolder) VALUES ('"+idFis.Text+ "','"+ numeFis.Text + "','" +idFoldFis.Text +"')",con);
cmd.ExecuteNonQuery();
con.Close();
}
Anyway as others said, it is a very bad idea to concatenate your query that way, since it could lead you to have sql injection on your code.

Try removing the , before the closing )
SqlCommand cmd = new SqlCommand("INSERT INTO Fisier (idFisier, Nume, idFolder) VALUES ('"+idFis.Text+ "','"+ numeFis.Text + "','" +idFoldFis.Text +"')",con);

Related

inserting data into SQL DB from C# ASP.NET

I am trying to insert values into my SQL database, the query works on the SQL side but when it comes to implement it from C# ASP.NET, it will not insert anything into the SQL database. The code is as follows:
public partial class About : Page
{
SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString);
protected void Page_Load(object sender, EventArgs e)
{
con.Open();
}
protected void Button1_Click(object sender, EventArgs e)
{
SqlCommand cmd = new SqlCommand("insert into sanctuary(SName) values('test')", con);
cmd = new SqlCommand("insert into species(Name) values('test1')", con);
cmd = new SqlCommand("insert into breed(SpeciesID, BreedName, FoodCost, HousingCost) SELECT SpeciesID, ('breed'), ('12'), ('21') FROM species", con);
cmd.ExecuteNonQuery();
con.Close();
}
}
}
Your help will be much appreciated!
If you want to execute three commands together you merge the sql of the three commands in a single string separating them with a semicolon (See Batch of Sql Commands)
string cmdText = #"insert into sanctuary(SName) values('test');
insert into species(Name) values('test1');
insert into breed(SpeciesID, BreedName, FoodCost, HousingCost)
SELECT SpeciesID, ('breed'), ('12'), ('21') FROM species";
SqlCommand cmd = new SqlCommand(cmdText, con);
cmd.ExecuteNonQuery();
The first problem in your code is that you need to execute each single command and not just the last one. Finally, if you don't see even the insert for the last command could be because your table species is empty and thus the final command has nothing to insert.
Last note, the point underlined by Zohar Peled about NOT keeping a global connection object around, is very important, follow the advice.
You only execute the last command, so there is nothing in species. Since there is nothing in species, the select returns no results so nothing gets inserted into breed.
Also, keeping an SqlConnection object on the page level is not a good idea. SQL connections should be opened right before executing queries and disposed immediately after.
A better code would look like this:
using(var con = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString))
{
using(var com = new SqlCommand("insert into sanctuary(SName) values('test');insert into species(Name) values('test1');insert into breed(SpeciesID, BreedName, FoodCost, HousingCost) SELECT SpeciesID, ('breed'), ('12'), ('21') FROM species", con)
{
con.Open();
com.ExecuteNonQuery();
}
}
You can, of course, execute each SQL statement separately (though in this case it's not the best course of action since it means 3 round trips to the database instead of just one):
using(var con = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString))
{
using(var com = new SqlCommand("insert into sanctuary(SName) values('test');", con)
{
con.Open();
com.ExecuteNonQuery();
com.CommandText = "insert into species(Name) values('test1');";
com.ExecuteNonQuery();
com.CommandText = "insert into breed(SpeciesID, BreedName, FoodCost, HousingCost) SELECT SpeciesID, ('breed'), ('12'), ('21') FROM species;";
com.ExecuteNonQuery();
}
}

Simple database Connection error in C#

I'm receiving the following error message:
invalidOperationException was unhandled
In the following code:
private void btnInsert_Click(object sender, EventArgs e)
{
SqlConnection conn = new SqlConnection("Data Source=DASTGIRKHAN\\SQLEXPRESS;Initial Catalog=DBProject;Integrated Security=True;Pooling=False");
conn.Open();
SqlCommand cmd = new SqlCommand("Insert INTO EmployeeRecord Values(" + tfCode.Text + ",'" + tfName.Text + "','" + tfCell.Text + "','" + tfAdrs + "',)");
cmd.BeginExecuteNonQuery();
cmd.ExecuteNonQuery();
conn.Close();
MessageBox.Show("Inserted Successfully");
}
InvalidOperationException exception is thrown when you invoke BeginExecuteNonQuery method (msdn) and you not specified "Asynchronous Processing=true" in the connection string.
You should also set connection to your command:
SqlCommand cmd = new SqlCommand("Insert INTO EmployeeRecord Values(" + tfCode.Text + ",'" + tfName.Text + "','" + tfCell.Text + "','" + tfAdrs + "')", conn);
InvalidOperationException
The name/value pair "Asynchronous Processing=true" was not included
within the connection string defining the connection for this
SqlCommand. The SqlConnection closed or dropped during a streaming
operation.
Sorry but your code has many errors. Let me show a different approach
private void btnInsert_Click(object sender, EventArgs e)
{
string cnString = #"Data Source=DASTGIRKHAN\\SQLEXPRESS;
Initial Catalog=DBProject;
Integrated Security=True;";
string cmdText = #"Insert INTO EmployeeRecord
Values(#code,#fname,#cell,#adr)";
using(SqlConnection conn = new SqlConnection(cnString))
using(SqlCommand cmd = new SqlCommand(cmdText, conn))
{
conn.Open();
cmd.Parameters.AddWithValue("#code", Convert.ToInt32(tfCode.Text));
cmd.Parameters.AddWithValue("#fname", tfName.Text );
cmd.Parameters.AddWithValue("#cell", tfCell.Text );
cmd.Parameters.AddWithValue("#adr", tfAdrs.Text);
int rowsInserted = cmd.ExecuteNonQuery();
if(rowInserted > 0)
MessageBox.Show("Inserted Successfully");
else
MessageBox.Show("Insert failes");
}
}
The primary cause of your error is stated by the answer of kmatyaszek, but this is just the tip of the iceberg.
You should always use the using statement around your disposable objects like the connection. This will ensure that the connection is closed and disposed also in case of exceptions.
You should use a parameterized query to create your command to avoid Sql Injection and parsing problems. For example, a single quote in the tfName textbox could lead to a Syntax Error.
The call to BeginExecuteNonQuery, excludes the call to ExecuteNonQuery and requires a call to EndExecuteNonQuery.
Finally, the result of ExecuteNonQuery tells you if the insertion is successful.
As a last note, I have remove the Pooling=False from the connection string.
You haven't said anything why do you want avoid his very useful optimization.
I'd print that SQL text. Looks like there's an unbalanced apostrophe to me.
Better yet, use a .NET class that binds parameters for you. Easier and better SQL injection projection, too.
What are tfCode, tfName,tfCell,tfAdrs? I assume they are textbox control?
if so you are using tfAdrs instead of tfAdrs.Text
also assign connection string to the command and remove additional space in
"Integrated security"
Why complicate yourself, use Parameterized Insert instead of concatenation, which its prone to SQL Injection.
SqlCommand command1 = new SqlCommand("INSERT INTO EmployeeRecord VALUES(#tfCode, #tfName, #tfCell, #tfAdrs)", conn);
command1.Parameters.AddWithValue("#tfCode", trCode);
command1.Parameters.AddWithValue("#tfName", tfName);
command1.Parameters.AddWithValue("#tfCell", tfCell);
command1.Parameters.AddWithValue("#tfAdrs", tfAdrs);

Inserting data into sql server fails with no reason

I'm quite used to using c# with SQL server. I have no idea why a simple statement would fail to insert data. My code is as follows:
query = "INSERT INTO MCDPhoneNumber ([MCDID],[PhoneNumber])" +
"VALUES("+maxid+", '"+tel+"')";
SqlConnection conn = new SqlConnection("Data Source=source; ...");
SqlCommand newCommand = new SqlCommand(query, conn);
int success= myCommand.ExecuteNonQuery();
if (success!= 1)
{
MessageBox.Show("It didn't insert anything:" + query);
}
First of all let me tell that I know that I should use parameters for data and I initially did, but when it failed I tried a simple query and it still fails. For addition I can tell that I have a similar insert just before that one in another table and it works. What's funnier is that when I copy paste query to SQL Server Management Studio it works. It also doesn't report any error in process.
====================== Edit ===============================
If you wish to use old command object (i.e. myCommand) then use following code instead of creating a new command(newCommand)
myCommand.CommandText = query;
myCommand.CommandType = System.Data.CommandType.Text;
And then execute it
you are binding query with newCommand and executing myCommand.
====================== Edit ===============================
SqlCommand newCommand = new SqlCommand(query, conn);
here you have defined newCommand for SQLCOMMAND object
int success= myCommand.ExecuteNonQuery();
and you are accessing it as myCommand
And moreover i think you are not opening connection
First of all, you define your command as newCommand but you executing your myCommand.
You should always use parameterized queries for your sql queries. This kind of string concatenations are open for SQL Injection attacks.
query = "INSERT INTO MCDPhoneNumber (MCDID, PhoneNumber) VALUES(#maxid, #tel)";
using(SqlConnection conn = new SqlConnection("Data Source=source; Initial Catalog=base; Integrated Security = true"))
{
SqlCommand newCommand = new SqlCommand(query, conn);
conn.Open();
newCommand.Parameters.AddWithValue("#maxid", maxid);
newCommand.Parameters.AddWithValue("#tel", tel);
int success= newCommand.ExecuteNonQuery();
if (success != 1)
{
MessageBox.Show("It didn't insert shit:" + query);
}
}
And please be more polite about your error messages :)

Taking data from a windows

What I need to do is basically take the users name (which is already stored as a variable) and their score (which is also a variable) and store it in my database when they press 'submit'. Here is the code I have for the button click.
private void btnSubmitScore_Click(object sender, EventArgs e)
{
string connStr = "server=server; " +
"database=databasename; " +
"uid=username; " +
"pwd=password;";
MySqlConnection myConn = new MySqlConnection(connStr);
}
Obviously i have changed the login details etc. I have had a look around and have only managed to find confusing codes about how to display data from a database in a form (i will do this later), but for now, i need to know how to add sName and iTotalScore into the database. (Fields are called 'Name' and 'Score' in DB)
You are going to use a combination of SqlConnection, SqlCommand and their properties. the connection is essentially the stuff of your code. The command is a literal SQL statement, or a call to a stored procedure.
A common C# idiom is to form your code around the very first line as shown here:
using (SqlConnection myConnection = new SqlConnection()) {
string doThis = "select this, that from someTable where this is not null";
SqlCommand myCommand = new SqlCommand(dothis, myConnection);
try {
myCommand.Connection.Open();
myReader = myCommand.ExecuteReader(); //pretend "myReader" was declared earlier
} catch (Exception myEx) {
// left to your imagination, and googling.
}
finally {
myCommand.Connection.Close();
}
}
// do something with the results. Your's to google and figure out
The general outline is
Using a connection
instantiate and configure an SqlCommand
Use try/catch as shown.
The "using" block gives use behind the scenes cleanup/disposal of all those objects we don't need anymore when we're done; in particular the SqlConnection object.
You must learn more about these Sqlxxxxx classes, there's lots of ways to configure them to do what you want.
I am not familiar with the MySql connector, but the code should be something along the lines of:
private void Insert()
{
string connStr = "server=server; " +
"database=databasename; " +
"uid=username; " +
"pwd=password;";
string query = "INSERT INTO TableName('Name','Score) VALUES (#name, #score);";
using(MySqlConnection connection = new MySqlConnection(connStr))
{
MySqlCommand insertCommand = new MySqlCommand(connection,command);
insertCommand.Paramaters.AddWithValue("#name",sName);
insertCommand.Paramaters.AddWithValue("#score",iTotalScore);
connection.Open();
command.ExecuteNonQuery();
connection.Close();
}
}

C# log in app with SQL [closed]

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Closed 11 years ago.
Hi I'm trying to get data from a local sql service database to take the input from a user register form. but when i push the button its not recorded onto the serviceable database.
do i need to use execute non query? how would i fix this code up? thanks
using System.Data.Sql;
using System.Data.SqlClient;
namespace Paddle_Power
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
Form2 form2 = new Form2();
form2.Show();
string connection = #"Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\PaddlePower.mdf;Integrated Security=True;User Instance=True";
SqlConnection cn = new SqlConnection(connection);
try
{
cn.Open();
MessageBox.Show("open");
}
catch (Exception)
{
MessageBox.Show("Did not connect");
}
string username = textBox1.Text;
string password = textBox2.Text;
string sqlquery = ("SELECT * FROM User WHERE Username = '" + textBox1.Text + "'");
sqlquery = "INSERT INTO [User] (Username, Password) VALUES ('" + textBox1.Text + "','" + textBox2.Text + "')";
SqlCommand command = new SqlCommand(sqlquery, cn);
command.Parameters.AddWithValue("Username", username);
command.Parameters.AddWithValue("Password", password);
command.Parameters.Clear();
}
}
}
Something along the lines of the following should hopefully do it. There's some room for improvement, but I at least hope it solves the problem you're having.
string connection = #"Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\PaddlePower.mdf;Integrated Security=True;User Instance=True";
object queryResult = null;
using (SqlConnection cn = new SqlConnection(connection))
{
cn.Open(); // Open connection
// SELECT
using (SqlCommand cmd = new SqlCommand("SELECT * FROM User WHERE Username = #Username AND Password = #Password", cn))
{
cmd.Parameters.AddWithValue("#Username", textBox1.Text);
cmd.Parameters.AddWithValue("#Password", textBox2.Text);
queryResult = cmd.ExecuteScalar();
}
// INSERT
using (SqlCommand cmd = new SqlCommand("INSERT INTO [User] (Username, Password) VALUES (#Username, #Password)", cn))
{
cmd.Parameters.AddWithValue("#Username", textBox1.Text);
cmd.Parameters.AddWithValue("#Password", textBox2.Text);
cmd.ExecuteNonQuery(); // or int affected = cmd.ExecuteNonQuery()
}
}
You can requse the first SqlCommand object or create a new one. There's very little difference with either way you choose to do it.
queryResult is just there for storing the result of cmd.ExecuteScalar(). You can map it to an object if you want (when selecting multiple columns) or cast it to a new type (if you're selecting a single column).
The direct answer is yes, you need to execute a non query. You see, you've prepared the command but you have not issued it. jstnasn's example should be very helpful. Take note of the using statements -- these will implicitly close the command when you exit the using statement, thus ensuring that the command is always closed when done.
The same occurs for the SqlConnection -- the using helps make sure that the connection is disposed of properly. However, if your database connection string allows connection pooling, then I believe the using statement will merely kill your object, without actually killing the connection to the database. This is advantageous because you will have lower I/O overhead the next time you need to open a database connection -- you'll just be connecting to an existing TCP/IP socket rather than opening a new on.
You have no parameters, nor do you ever actually send the query to the database
// parameter placeholders defined with #parameter_name
sqlquery = "INSERT INTO [User] (Username, Password) VALUES (#username, #Password);
SqlCommand command = new SqlCommand(sqlquery, cn);
command.Parameters.AddWithValue("#Username", username);
command.Parameters.AddWithValue("#Password", password);
// This will make the query happen on the database.
// It will handle sending the parameters and all that good stuff
// http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlcommand.executenonquery.aspx
command.ExecuteNonQuery();

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