I am currently reading and parsing 10 different file(.txt, .csv), each file has a different number of columns.
Here is a sample from one file:
SqlCommand cmd = new SqlCommand("insert into " + table_name + " VALUES('"+data_from_file[0]+"', '" + data_from_file[1] + "', '" + data_from_file[2] + "', '" + data_from_file[3] + "', '" + data_from_file[4] + "','" + data_from_file[5] + "', '" + data_from_file[6] + "', '" + data_from_file[7] + "', '" + data_from_file[8] + "', '" + data_from_file[9] + "');", connection);
cmd.ExecuteNonQuery();
This file has a total of 10 columns that gets inserted into its own table. If I do it like this for the 10 files, I would have 10 different if/else if statements. And to me that sounds like bad way of doing this. Is there a way to iterate through the array and insert each element? I have been looking for ways to do it, but cannot find a proper solution for my problem. Thanks for the help.
The most classical way would be to iterate and append to a string and then execute:
string command = "insert into " + table_name + " VALUES(";
foreach(string data in data_from_file)
{
command += "'" + data + "',";
}
command = command.TrimEnd(','); // remove the last extra ','
command += ");";
SqlCommand cmd = new SqlCommand(command);
cmd.ExecuteNonQuery();
However, I recommend that you have a look at SqlBulkCopy for Large Insert Queries.
First you iterate over your collection, and then you insert every entry from the collection into the database.
foreach (var oneColumn in data)
{
SqlCommand cmd = new SqlCommand("INSERT INTO " + table_name + " VALUES(" + oneColumn + ")");
cmd.ExecuteNonQuery();
}
Related
I'm trying to remake my system and my older system is 100% working, but when I changed something (I added a lot of columns in ms access database) I did the correct format in inserting data of each textboxes but it still says "error in insert into statement".
This is my code. Please take your time reading the query for that is only the error I got. I double checked the spelling or capitalization on each field from database as well as here.
try
{
connection.Open(); //open connection
OleDbCommand command = new OleDbCommand(); // command object , we can execute to validate our database
command.Connection = connection; // make a connection for the command
command.CommandText = " insert into StudentsRecord([StudentID],Name,Section,Semester,MathPrelim,MathMidterm,MathFinals,MathAverage,MathFinalGrade,EnglishPrelim,EnglishMidterm,EnglishFinals,EnglishAverage,EnglishFinalGrade,SciencePrelim,ScienceMidterm,ScienceFinals,ScienceAverage,ScienceFinalGrade,StatisticsPrelim,StatisticsMidterm,StatisticsFinals,StatisticsAverage,StatisticsFinalGrade,ReadandWritePrelim,ReadandWriteMidterm,ReadandWriteFinals,ReadandWriteAverage,ReadandWriteFinalGrade) values ('" + txtStudentID.Text + "' , '" + txtName.Text + "' , '" + txtSection.Text + "' , '" + cmbSemester.SelectedItem + "', '" + txtMathp.Text + "' , '" + txtMathm.Text + "' , '" + txtMathf.Text + "' , '" + txtMatha.Text + "' , '" + txtMathFG.Text + "' , '" + txtEnglishp.Text + "' , '" + txtEnglishm.Text + "', '" + txtEnglishf.Text + "','" + txtEnglisha.Text + "','" + txtEnglishFG.Text + "','" + txtMathFG.Text + "','" + txtSciencep.Text + "','" +txtSciencem.Text+ "','" + txtSciencef.Text + "','" + txtSciencea.Text + "','" + txtScienceFG.Text + "','" + txtStatisticsp.Text + "','" + txtStatisticsm.Text + "','" + txtStatisticsf.Text + "','" + txtStatisticsa.Text + "','" + txtStatisticsFG.Text + "','" + txtReadandWritep.Text + "','" + txtReadandWritem.Text + "','" + txtReadandWritef.Text + "','" + txtReadandWritea.Text + "','" + txtReadandWriteFG.Text + "')";
/* this is a string or a query used to execute. asterisk is used
to give you all column data from your database ,declaration of query */
command.ExecuteNonQuery(); // this is used to inserting data , updating or deleting data , this command will execute the above query
MessageBox.Show(" Saved! ");
}
catch (Exception a)
{
MessageBox.Show(" Error " + a.Message);
}
connection.Close();
I see in the first part you have 29 fields, but the inserted fields are 30...
In addition, you should use parameterized queries to avoid sql injection.
You need to debug codes and paste your CommandText to SSMS(SQL Sever Management Studio) to figure out errors.
Other suggestions:
command.CommandText = string.format("insert into StudentsRecord(..) VALUES(#...)); sql params to avoid sql injection
using(SqlConnection conn = ...)
Already solved the problem just now by putting [ ] on each field. which will be something like this:
insert into StudentsRecord(
[StudentID],[Name],[Section],[Semester],
[MathPrelim],[MathMidterm],[MathFinals]
) values ('"++"'..) ... etc.
Thanks everyone who tried to help me, have a good day!
I have a table in mysql for users. Sometime user has a boss and sometime it don't.
So boss data type in nullable int(it is a foreign key, that's why nullable INT).
I was using following code and it was causing problem when boss value is null, producing following error "Incorrect integer value: '' for column 'boss_id' at row 1"
string query = " INSERT INTO " + databasename + ".system_user (" +
"`boss_id`, " +
"`name`, " +
"`user_name`, " +
"`password_2`, " +
"`designation`," +
"`digital_signature`," +
"`functional_role`," +
"`group_2`) " +
"VALUES ('" +
systemuser.Boss + "', '" +
systemuser.Name + "','" +
systemuser.UserName + "', '" +
systemuser.Password + "', '" +
systemuser.Designation + "', '" +
systemuser.DigitalSignature + "', '" +
systemuser.FunctionalRole + "', '" +
systemuser.Group + "');";
MySqlConnection conDataBase = new MySqlConnection(myconnection);
MySqlCommand cmdDataBase = new MySqlCommand(query, conDataBase);
MySqlDataReader myreader;
try
{
conDataBase.Open();
myreader = cmdDataBase.ExecuteReader();
conDataBase.Close();
return true;
}
catch (Exception ex)
{
conDataBase.Close();
MessageBox.Show(ex.Message);
return false;
}
So, i changed the code for string query as follow:
string query = "";
if(systemuser.Boss!=null)
{
query = " INSERT INTO " + databasename + ".system_user (" +
"`boss_id`, " +
"`name`, " +
"`user_name`, " +
"`password_2`, " +
"`designation`," +
"`digital_signature`," +
"`functional_role`," +
"`group_2`) " +
"VALUES ('" +
systemuser.Boss + "', '" +
systemuser.Name + "','" +
systemuser.UserName + "', '" +
systemuser.Password + "', '" +
systemuser.Designation + "', '" +
systemuser.DigitalSignature + "', '" +
systemuser.FunctionalRole + "', '" +
systemuser.Group + "');";
}
else
{
query = " INSERT INTO " + databasename + ".system_user (" +
"`name`, " +
"`user_name`, " +
"`password_2`, " +
"`designation`," +
"`digital_signature`," +
"`functional_role`," +
"`group_2`) " +
"VALUES ('" +
systemuser.Name + "','" +
systemuser.UserName + "', '" +
systemuser.Password + "', '" +
systemuser.Designation + "', '" +
systemuser.DigitalSignature + "', '" +
systemuser.FunctionalRole + "', '" +
systemuser.Group + "');";
}
It worked because, Mysql by default put null at the skipped values.
Now according to my scenario, I have to update boss_id from int to null and sometime from null to int. But my query always skip if value is null. Can you please help me in changing the insert statement in such a way that it would insert null value in boos(if its null) and don't just skip it.
Firstly, you should use parameters, it gives you a clean code and avoid injection.
You can use parameters like this:
string query = string.Format("INSERT INTO {0}.system_user (`boss_id`, `name`, `user_name`, `password_2`, `designation`, `digital_signature`, `functional_role`, `group_2`)" +
"VALUES (#boss_id, #name, #user_name, #password_2, #designation, #digital_signature, #functional_role, #group_2)", databasename);
MySqlConnection conDataBase = new MySqlConnection(myconnection);
MySqlCommand cmdDataBase = new MySqlCommand(query, conDataBase);
cmdDataBase.Parameters.AddWithValue("#boss_id", systemuser.Boss ?? (object)DBNull.Value);
cmdDataBase.Parameters.AddWithValue("#name", systemuser.Name);
cmdDataBase.Parameters.AddWithValue("#user_name", systemuser.UserName);
cmdDataBase.Parameters.AddWithValue("#password_2", systemuser.Password);
cmdDataBase.Parameters.AddWithValue("#designation", systemuser.Designation);
cmdDataBase.Parameters.AddWithValue("#digital_signature", systemuser.DigitalSignature);
cmdDataBase.Parameters.AddWithValue("#functional_role", systemuser.FunctionalRole);
cmdDataBase.Parameters.AddWithValue("#group_2", systemuser.Group);
Note "#boss_id", systemuser.Boss ?? (object)DBNull.Value, this is because you can not use null directly in the parameters.
UPDATE:
If you want to update or delete you can use parameters too:
You can write your queries like this:
string query = string.Format("UPDATE {0}.system_user SET `name` = #name WHERE `boss_id` = #boss_id", databasename);
or
string query = string.Format("DELETE FROM {0}.system_user WHERE `boss_id` = #boss_id", databasename);
For datetime columns you can see this question. It has very good answers.
You are encapsulating the value of Systemuser.Boss in single quotes, doesn't this indicate that you are trying to insert a string into an integer column?
string query = #"INSERT INTO {0}.system_user (
`boss_id`,
`name`,
`user_name`,
`password_2`,
`designation`,
`digital_signature`,
`functional_role`,
`group_2`)
VALUES
{1},
'{2}',
'{3}',
'{4}',
'{5}',
'{6}',
'{7}',
'{8}')
";
string formattedQuery = string.Format(query,
databasename, // {0}
Systemuser.Boss, // {1}
Systemuser.Name, // {2}
etc, etc);
EDIT: missed a part where you said 'when it was null'... you need to use:
(Systemuser.Boss ?? "NULL")
I'm getting the error:
Data type mismatch in criteria expression
When using this code. And using Access database.
OleDbConnection bab = new OleDbConnection();
bab.ConnectionString = #"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\sdega\OneDrive\school\Werknemersdata.accdb;Persist Security Info=False;";
bab.Open();
try
{
OleDbCommand kaas = new OleDbCommand();
kaas.Connection = bab;
kaas.CommandText = "insert into Werknemersdata (Naam, Adres, Postcode, Woonplaats, Salaris) values ('" + txtNaam.Text + "', '" + txtAdress.Text + "', '" + txtpostcode1.Text + " " +txtpostcode2.Text + "', '" + txtwoonplaats.Text + "', '" + txtsalaris.Text + "') ";
kaas.ExecuteNonQuery(); // this is where it goes wrong
txtStatus.BackColor = Color.Green;
MessageBox.Show("data saved");
bab.Close();
}
catch (Exception ghakbal)
{
MessageBox.Show("Error" + ghakbal);
}
You missed one ' after '" + txtpostcode1.Text + " and one before " +txtpostcode2.Text + "' and also one , between them. It should be like this:
'" + txtpostcode1.Text + "' , '" +txtpostcode2.Text + "',
Also I strongly recommend that you always use parameterized queries to avoid SQL Injection. Like this:
kaas.CommandText = "insert into Werknemersdata (Naam, Adres, Postcode, Woonplaats, Salaris) values (?, ? ,.....");
kaas.Parameters.AddWithValue("Naam", txtNaam.Text);
kaas.Parameters.AddWithValue("Adres", txtAdress.Text);
//And other parameters...
Also It would be better to specify the type directly and use the Value property. Read more here.
I have data set that is being filled from sql query, like this
cmd_sql.CommandText = " SELECT BrDok " +
" FROM ordersstavke " +
" WHERE SifParFil = '" + rw_mat["sifskl_kor"] + "'";
MySqlDataAdapter sql_adapter = new MySqlDataAdapter(cmd_sql);
DataSet ds_dok = new DataSet("ordersstavke");
sql_adapter.Fill(ds_dok);
Now I want to extract value from data set for sql update, like this one
myQuery = "UPDATE ordersstavke " +
"SET BrDok = '" + rw_mat["brdok"] + "', " +
"SifParFil = '" + rw_mat["sifskl_kor"] + "', " +
"WHERE BrDok = " + ds_dok.Tables["ordersstavke"].Rows[0]["BrDok"] + "'";
I tried this ds_dok.Tables["ordersstavke"].Rows[0]["BrDok"] but I got an error,
I was thinking to do something like this
string BrDok;
BrDok = ds_dok.["BrDok"].ToString();
But nothing, how to extract that BrDok or just put it into procedure?
Thanks infront!
Make it
DataSet ds_dok = new DataSet("ordersstavke");
sql_adapter.Fill(ds_dok,"BrDok");
Then use
ds_dok.Tables["BrDok"].Rows[0]["BrDok"].ToString()
Try this
ds_dok.Tables[0].Rows[0]["BrDok"]
If you provide a string argument for the dataset class, then it will be the dataset name and not the datatable name. And there is no table in the database with name you provided for a dataset, so give it while filling the dataset. Write some thing like below.
DataSet ds_dok = new DataSet();
sql_adapter.Fill(ds_dok,"ordersstavke");
and you can write all the remaining code as it is in your code part.
And your second update query has some syntax error, see it like below
myQuery = "UPDATE ordersstavke " + "SET BrDok = '" + rw_mat["brdok"] + "', "
+ "SifParFil = '" + rw_mat["sifskl_kor"] + "', " + "WHERE BrDok
= '" + ds_dok.Tables["ordersstavke"].Rows[0]["BrDok"] + "'";
You forgot to put an starting inverted comma at the where clause.
Just a small hint to the sql-command. You should use sql-parameters to prefent sql-injection.
I have a windows service which inserts data into some tables. It does so fine when in debug mode, but when I install it says "Data type mismatch in criteria expression." for every insert.
query = "INSERT INTO printers (" +
"hostname," +
"ip_address," +
"model," +
"picture_id," +
"connect_type," +
"status," +
"product_number," +
"Floor_ID," +
"print_corner," +
"serial_number," +
"printer_features" +
") VALUES ('" +
exp.Devices[i].HostName.ToString() + "', '" +
exp.Devices[i].IpAddress.ToString() + "', '" +
exp.Devices[i].Model.ToString() + "', '" +
exp.Devices[i].PictureId.ToString() + "', '" +
exp.Devices[i].ConnectType.ToString() + "', '" +
exp.Devices[i].Status.ToString() + "', '" +
exp.Devices[i].ProductNumber.ToString() + "', '" +
exp.Devices[i].Floor.ToString() + "', '" +
exp.Devices[i].PrintCorner.ToString() + "', '" +
exp.Devices[i].SerialNumber.ToString() + "', '" +
exp.Devices[i].PrinterFeatures.ToString() +
"')";
connectionString = "Provider=Microsoft.Jet.OLEDB.4.0; Data Source=" + confParams.MpaSearchDatabase;
OleDbConnection conn = new OleDbConnection(connectionString);
OleDbCommand myCommand = new OleDbCommand(query);
myCommand.Connection = conn;
conn.Open();
myCommand.ExecuteNonQuery();
conn.Close();
insertedPrintersCount = insertedPrintersCount + 1;
Utils.Logger.Info("Device inserted: " + exp.Devices[i].HostName);
help!
The data type mismatch error indicates the query is expecting data of one type but you're providing another. This query expression is passing every value as a string literal but several columns indicate they are likely a numerical value. ProductNumber and SerialNumber for example.
In order to pass the values correctly (and prevent easy injection attacks) you'll want to use the OleDbCommand class to build up the call with values of the correct type. Then let the underlying infrastructure translate it to the appropriate values.