How to set sql parameters - c#

I try that code for use sql parameters but didnt work and didnt return any error. How can I fix it?
string sql = "SELECT * FROM "+mw.db_name+".ananmez_genel Where hasta_id='#hastaid'";
string connectionString = ConfigurationManager.ConnectionStrings["MYDBConnectionString"].ConnectionString;
using (MySqlConnection connect = new MySqlConnection(connectionString))
{
using (MySqlCommand cmd = new MySqlCommand(sql, connect))
{
connect.Open();
cmd.Parameters.AddWithValue("#hastaid",hasta_id);
MySqlDataReader mdr;
mdr = cmd.ExecuteReader();
if (mdr.Read())
{
for (int i = 0; i < 20; i++)
{
arti = (i + 1).ToString();
kontrol = mdr.GetString("c_" + arti);
if (kontrol == "True")
{
ananmezcheck.ananmez_gnlkontrol(i, check);
}
}
yirmibir.Text = mdr.GetString("txt_1");
}
connect.Close();
}
If i using just like that, it works:
string sql = "SELECT * FROM "+mw.db_name+".ananmez_genel Where hasta_id='"+hastaid+"'";
so there is no problem in the database.

This part is the problem:
Where hasta_id='#hastaid'
That's not using a parameter - that's searching for rows where the value of hasta_id is exactly the string #hastaid, because you've put it in a string literal. You need to get rid of the quotes:
Where hasta_id=#hastaid
Then it's looking for rows where the value of hasta_id matches the value of the parameter #hastaid.

Related

If the SELECT SQL Server value is null, the query takes 5 minutes C #

I have a very silly problem. I am doing a select, and I want that when the value comes null, return an empty string. When there is value in sql query, the query occurs all ok, but if there is nothing in the query, I have to give a sqlCommand.CommandTimeout greater than 300, and yet sometimes gives timeout. Have a solution for this?
public string TesteMetodo(string codPess)
{
var vp = new Classe.validaPessoa();
string _connection = vp.conString();
string query = String.Format("SELECT COUNT(*) FROM teste cliente WHERE cod_pess = {0}", codPess);
try
{
using (var conn = new SqlConnection(_connection))
{
conn.Open();
using (var cmd = new SqlCommand(query, conn))
{
SqlDataReader dr = cmd.ExecuteReader();
if(dr.HasRows)
return "";
return codPess;
}
}
}
You should probably validate in the UI and pass an integer.
You can combine the usings to a single block. A bit easier to read with fewer indents.
Always use parameters to make the query easier to write and avoid Sql Injection. I had to guess at the SqlDbType so, check your database for the actual type.
Don't open the connection until directly before the .Execute. Since you are only retrieving a single value you can use .ExecuteScalar. .ExecuteScalar returns an Object so must be converted to int.
public string TesteMetodo(string codPess)
{
int codPessNum = 0;
if (!Int32.TryParse(codPess, out codPessNum))
return "codPess is not a number";
var vp = new Classe.validaPessoa();
try
{
using (var conn = new SqlConnection(vp.conString))
using (var cmd = new SqlCommand("SELECT COUNT(*) FROM teste cliente WHERE cod_pess = #cod_pess", conn))
{
cmd.Parameters.Add("#cod_pess", SqlDbType.Int).Value = codPessNum;
conn.Open();
int count = (int)cmd.ExecuteScalar();
if (count > 0)
return "";
return codPess;
}
}
catch (Exception ex)
{
return ex.Message;
}
}

Is there a way to validate the connection string if the server is closed or down?

I have problem regarding inserting the loop process. So when the connection string determine that the server is down, the inserting process stop looping. My question, is there way to determine whether this connection string is down or not? I have research they answer is to make if condition sqlconn.State == ConnectionState.Open I will show you guys the sample error that I encounter.
string connetionString = null;
MySqlConnection cnn;
connetionString = "server=localhost;database=sample_db_xx;uid=root;pwd=;";
cnn = new MySqlConnection(connetionString);
try
{
var arpp_pro = new List<string>();
cnn.Open();
MySqlCommand command = new MySqlCommand("SELECT store_id,CONCAT(boh,'\\\\sqlexpress') as boh FROM db_cua.stores WHERE " +
"is_active = 1 AND boh != '' ", cnn);
using (MySqlDataReader reader = command.ExecuteReader())
{
while (reader.Read())
{
Console.WriteLine(reader[0].ToString());
arpp_pro.Add(reader[1].ToString());
}
}
cnn.Close();
foreach (var arpp_pro_data in arpp_pro)
{
string connetionString_SQL = #"Server=" + arpp_pro_data + " \sqlexpress;Database=Site5;User ID=sa;Password=dospos";
//#"Server=" + arpp_pro_data + ";Database=Site5;User ID=sa;Password=dospos";
var date_minus_one_day = DateTime.Today.AddDays(-1);
var formatted_date_minus_one_day = date_minus_one_day.ToString("yyyy-MM-dd");
var year = DateTime.Now.ToString("yyyy");
var month = DateTime.Now.ToString("MM");
var date = DateTime.Today.AddDays(-1);
var date_formatted = date.ToString("dd");
string get_sos_orders_details = #"SELECT
Convert(nvarchar(50),dbo.SOS_ORDERS.OrderId)+ '-'+ Convert(nvarchar(50),dbo.SOS_ORDERS.TransTime) + Convert(nvarchar(50),dbo.Sales.TransactionId)+ Convert(nvarchar(50),dbo.Sales.TotalDeptName) as result,
dbo.Sales.StoreId,
Convert(nvarchar(50),dbo.SOS_ORDERS.TransTime) as TransTime,
dbo.Transactions.OperatorName as Cashier,
dbo.Sales.TotalDeptName as Transaction_Type,
dbo.Sales.TransactionId,
(dbo.SOS_ORDERS.DTOT + dbo.SOS_ORDERS.ASSM) as Cashier_Time,
(dbo.SOS_ORDERS.KIT) as Preparation_Time,
(dbo.SOS_ORDERS.KIT + dbo.SOS_ORDERS.DTOT + dbo.SOS_ORDERS.ASSM) as Total_Time
FROM dbo.SOS_ORDERS INNER JOIN
dbo.Sales ON dbo.SOS_ORDERS.OrderId = dbo.Sales.StoredOrderIndex INNER JOIN
dbo.Transactions ON dbo.Sales.Sequence = dbo.Transactions.Sequence
where dbo.Sales.businessdate= #date_minus_one_day
OR(DATEPART(yy, dbo.SOS_ORDERS.TransTime) = #year
AND DATEPART(mm, dbo.SOS_ORDERS.TransTime) = #month
AND DATEPART(dd, dbo.SOS_ORDERS.TransTime) = #date_today )
AND(dbo.Sales.TotalDeptName in ('01 SALLE MANGER', '02 EMPORTER')
or dbo.Sales.TotalDeptName in ('01 DINE IN', '02 TAKE OUT'))
GROUP BY dbo.SOS_ORDERS.OrderId, dbo.Sales.StoreId, dbo.SOS_ORDERS.TransTime, dbo.SOS_ORDERS.DTOT, dbo.SOS_ORDERS.LINE, dbo.SOS_ORDERS.WIND, dbo.SOS_ORDERS.SERV, dbo.SOS_ORDERS.HOLD,
dbo.SOS_ORDERS.TOTL, dbo.SOS_ORDERS.ASSM, dbo.SOS_ORDERS.CASH, dbo.SOS_ORDERS.FTOT, dbo.SOS_ORDERS.PAY, dbo.SOS_ORDERS.KIT, dbo.Sales.TransactionId,
dbo.Transactions.OperatorName, dbo.Sales.TotalDeptName order by dbo.SOS_ORDERS.TransTime DESC";
using (SqlConnection sqlconn = new SqlConnection(connetionString_SQL))
{
sqlconn.Open();
if (sqlconn.State == ConnectionState.Open)
{
SqlCommand cmd = new SqlCommand(get_sos_orders_details, sqlconn);
cmd.Parameters.AddWithValue("#date_minus_one_day", formatted_date_minus_one_day);
cmd.Parameters.AddWithValue("#year", year);
cmd.Parameters.AddWithValue("#month", month);
cmd.Parameters.AddWithValue("#date_today", date_formatted);
SqlDataReader rs = cmd.ExecuteReader();
while (rs.Read())
{
// access your record colums by using reader
Console.WriteLine(rs["StoreId"]);
cnn.Open();
MySqlCommand comm = cnn.CreateCommand();
comm.CommandText = #"INSERT INTO master_data.so_v2 (StoreId,TransTime,Cashier,Transaction_Type,TransactionId,Cashier_Time,Preparation_Time)
VALUES(#Storeid, #TransTime, #Cashier, #Transaction_Type, #TransactionId, #Cashier_Time, #Preparation_Time)";
comm.Parameters.AddWithValue("#Storeid", rs["StoreId"]);
comm.Parameters.AddWithValue("#TransTime", rs["TransTime"]);
comm.Parameters.AddWithValue("#Cashier", rs["Cashier"]);
comm.Parameters.AddWithValue("#Transaction_Type", rs["Transaction_Type"]);
comm.Parameters.AddWithValue("#TransactionId", rs["TransactionId"]);
comm.Parameters.AddWithValue("#Cashier_Time", rs["Cashier_Time"]);
comm.Parameters.AddWithValue("#Preparation_Time", rs["Preparation_Time"]);
comm.ExecuteNonQuery();
cnn.Close();
}
}
sqlconn.Close();
}
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
Thank you.
I suppose if all you wanted was a way to test and make sure a connection string is valid and that you can connect to the server and to the database, you could use a method like this:
public bool IsConnectionStringValid(string cs)
{
try
{
using (MySqlConnection conn = new MySqlConnection(cs))
{
conn.Open();
return true;
}
}
catch
{
return false;
}
}
Although I have to admit, in all my years of developing in C#, I've never used anything like this. Normally, as people have said in the comments, you already know before runtime that your connection string is valid and working.

c# mysql unable to output query to a textbox

here is my code:
private void searchInDatabase()
{
MySqlConnection c = new MySqlConnection("datasource=localhost; username=root; password=123456; port=3306");
MySqlCommand mcd;
MySqlDataReader mdr;
String query;
try
{
c.Open();
query = "SELECT * FROM test.classmates WHERE first_name ='"+searchName.Text+"'";
mcd = new MySqlCommand(query, c);
mdr = mcd.ExecuteReader();
if(mdr.Read())
{
firstName.Text = mdr.GetString("first_name");
middleName.Text = mdr.GetString("middle_name");
lastName.Text = mdr.GetString("last_name");
age.Text = mdr.GetString("age");
}
else
{
MessageBox.Show("Result Not Found");
}
}
catch(Exception error)
{
MessageBox.Show("Error: "+error.Message);
}
finally
{
c.Close();
}
}
I would like to ask for a help if I have missed on anything or I am doing it wrong. If you have free time, I will much appreciate it if you will comment the perfect way to do I implement this problem: I want to get data from MySQL then put it in a textbox.
According to MSDN you need to pass the column number as parameter
public override string GetString(int i)
So try to pass the column number (starts from 0) of your column name. Assuming the first_name is the first column of your table then
firstName.Text = mdr.GetString(0);
UPDATE
Try to use MySqlConnectionStringBuilder
MySqlConnectionStringBuilder conn_string = new MySqlConnectionStringBuilder();
conn_string.Server = "serverip/localhost";
conn_string.UserID = "my_user";
conn_string.Password = "password";
conn_string.Database = "my_db";
MySqlConnection conn = new MySqlConnection(conn_string.ToString();
First of all look at this sample of connection string and change your connection string:
'Server=myServerAddress;Port=1234;Database=myDataBase;Uid=myUsername;Pwd=myPasswor;'
If connection is OK send erorr message or full exception.

CommandText property has not been initialized error in gridview

I have a gridview and I want to checked line in insert but I see this error:
CommandText property has not been initialized.
I guess my mistake about strArrays. I'm working two days about it
How can I fixed?
StringBuilder stringBuilder = new StringBuilder(string.Empty);
SqlConnection sqlConnection = new SqlConnection(ConfigurationManager.ConnectionStrings["SiteSqlServer"].ConnectionString.ToString());
SqlCommand sqlCommand = new SqlCommand();
for (int i = 0; i < GridView1.Rows.Count; i++)
{
int type = 2;
CheckBox chkUpdate = (CheckBox)GridView1.Rows[i].Cells[0].FindControl("chkSelect");
TextBox txtAmount = (TextBox)GridView1.Rows[i].Cells[5].FindControl("txtAmount");
if (chkUpdate != null)
{
if (chkUpdate.Checked)
{
string strID = GridView1.Rows[i].Cells[1].Text;
GridView1.Rows[i].FindControl("txtLocation")).Text;
string text = this.GridView1.Rows[i].Cells[1].Text;
string[] strArrays = new string[] { "INSERT INTO [OrderCancel]
([OrderID],
[Message],
[Type],
[RelationProductID],
[Amount])
VALUES(" ,
Request.QueryString["o"] ,
",'" , txtWhy.Text ,
"',",type.ToString(),",
" , strID , "," ,
txtAmount.Text , ");" };
stringBuilder.Append(string.Concat(strArrays));
//append update statement in stringBuilder
stringBuilder.Append(string.Concat(strArrays));
}
}
try
{
try
{
sqlCommand.CommandType = CommandType.Text;
sqlCommand.CommandText = stringBuilder.ToString();
sqlCommand.Connection = sqlConnection;
sqlConnection.Open();
sqlCommand.ExecuteNonQuery();
}
catch (SqlException sqlException)
{
throw new Exception(string.Concat("Error in Updation",
sqlException.Message));
}
}
finally
{
sqlConnection.Close();
}
Your code could be cleaned up, you could do the following:
private readonly string dbConnection = "...";
private const string query = "... Column = #Column";
For the sake of brevity I've added ... which will correlate to your Connection String and your query with parameters.
var message = String.Empty;
using(var connection = new SqlConnection(dbConnection))
using(var command = new SqlCommand(query, dbConnection))
{
connection.Open();
command.CommandType = CommandType.Text;
command.Parameters.Add("#Column", SqlDbType.NVarChar).Value = message;
command.ExecuteNonQuery();
}
So that small snippet would be inside of a method, which would pass a model of the data in your Grid. Then when you pass a value from your Grid, then you would build your model and pass to the method which will write to your database.
Also, when you use a StringBuilder you will also need to call ToString(); to ensure that it is a string rather than a StringBuilder when your utilizing.
This error usually happens if you do not set the commandText property. looking at your code it looks like your stringbuilder variable is not getting set. have you tried putting a breakpoint inside your "chkUpdate.Checked" loop? if yes, can you post the sql that gets constructed in your loop

C#, MySQL - fatal error encountered during command execution- Checked other solutions, something I am Missing

I have looked at the other questions with this title and I think the problem is something local with my code that I am missing.
The function that this button preforms is to calculate the points/rewards that a person earns based on the transaction total. For example, $10 = 1 point, 19=1 point, 20=2. 10 Points = 1 Rewards points, which is equal to a ten dollar credit.
My Code receives the title error message. I will include the entire function for completeness.
private void button1_Click(object sender, EventArgs e)
{
try{
string cs = #"server=localhost;userid=root;password=root;database=dockingbay94";
MySqlConnection conn;
//MySqlDataReader rdr = null;
using (conn = new MySqlConnection(cs));
if (conn.State != ConnectionState.Open)
{
conn.Open();
}
string input = textBox2.Text;
MySqlCommand myCommand2 = conn.CreateCommand();
myCommand2.CommandText = "SELECT Points FROM members WHERE id = #input";
MySqlDataAdapter MyAdapter2 = new MySqlDataAdapter();
MyAdapter2.SelectCommand = myCommand2;
double transaction = Convert.ToDouble(textBox3.Text);
double tmp_transaction = Math.Floor(transaction);
string transaction_date = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");
double pointsbefore = (tmp_transaction / 10.0);
int currentpoints = Convert.ToInt32(pointsbefore);
int rewards = 0;
int oldpoints = 0;
string temp = "";
pointsbefore = Math.Floor(pointsbefore);
int new_points;
double tmp_rewards = 0.0;
double tmp_points;
int new_rewards;
oldpoints = (int)myCommand2.ExecuteScalar();
new_points = currentpoints + oldpoints;
tmp_points = new_points / 10;
int tmp_rewards2 = 0;
if (new_points > 10)
{
tmp_rewards = Math.Floor(tmp_points);
tmp_rewards2 = Convert.ToInt32(tmp_rewards);
}
else if (new_points == 10)
{
tmp_rewards2 = 1;
}
else
{
tmp_rewards2 = 0;
}
new_rewards = rewards + tmp_rewards2;
int points_left = 0;
if (new_points > 10)
{
for (int i = 10; i < new_points; i++)
{
points_left++;
}
}
else if (new_points == 10)
{
points_left = 0;
}
else if (new_points < 10)
{
for (int i = 0; i < new_points; i++)
{
points_left++;
}
}
string query = "UPDATE members Set Points=#Points, rewards_collected=#Rewards, transaction_total=#Transaction, transaction_date=#TransactionDate" + "WHERE id = #input;";
MySqlCommand cmdDataBase = new MySqlCommand(query, conn);
cmdDataBase.Parameters.Add("#input", SqlDbType.Int).Value = Convert.ToInt32(textBox2.Text);
cmdDataBase.Parameters.AddWithValue("#Points", new_points);
cmdDataBase.Parameters.AddWithValue("#Rewards", new_rewards);
cmdDataBase.Parameters.AddWithValue("#Transaction", textBox3.Text);
cmdDataBase.Parameters.AddWithValue("#TransationDate", transaction_date);
MySqlDataReader myReader2;
myReader2 = cmdDataBase.ExecuteReader();
MessageBox.Show("Data Updated");
if(conn.State == ConnectionState.Open){
conn.Close();
}
}
catch(Exception ex)
{
MessageBox.Show(ex.Message);
}
}
}
I am not sure where the error could be. Probably not sending the right value.
Thanks
This line is wrong
using (conn = new MySqlConnection(cs));
Remove the semicolon and include everything that needs the MySqlConnection variable inside a {} block
using (MySqlConnection conn = new MySqlConnection(cs))
{
// No need to test if the connection is not open....
conn.Open();
.........
// Not needed (at least from your code above
// MySqlDataAdapter MyAdapter2 = new MySqlDataAdapter();
// MyAdapter2.SelectCommand = myCommand2;
... calcs follow here
// Attention here, if the query returns null (no input match) this line will throw
oldpoints = (int)myCommand2.ExecuteScalar();
.... other calcs here
MySqlCommand cmdDataBase = new MySqlCommand(query, conn);
cmdDataBase.Parameters.Add("#input", SqlDbType.Int).Value = Convert.ToInt32(textBox2.Text);
cmdDataBase.Parameters.AddWithValue("#Points", new_points);
cmdDataBase.Parameters.AddWithValue("#Rewards", new_rewards);
cmdDataBase.Parameters.AddWithValue("#Transaction", textBox3.Text);
cmdDataBase.Parameters.AddWithValue("#TransationDate", transaction_date);
// Use ExecuteNonQuery for INSERT/UPDATE/DELETE and other DDL calla
cmdDataBase.ExecuteNonQuery();
// Not needed
// MySqlDataReader myReader2;
// myReader2 = cmdDataBase.ExecuteReader();
// Not needed, the using block will close and dispose the connection
if(conn.State == ConnectionState.Open)
conn.Close();
}
There is also another error in the final query. Missing a space between #TransactionDate parameter and the WHERE clause. In cases where a long SQL command text is needed I find very useful the verbatim string line character continuation #
string query = #"UPDATE members Set Points=#Points, rewards_collected=#Rewards,
transaction_total=#Transaction, transaction_date=#TransactionDate
WHERE id = #input;";

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