I created a Windows Forms application in C# and my database in Visual Studio. I want to know how, if it's possible, to sort one of the columns in the table by clicking a button? Or how can I sort this column automatically without using a button?
I've tried to implement this sort in the code below, but it doesn't work :(
private c void button5_Click(object sender, EventArgs e)
{
SqlConnection sqlConnection = new SqlConnection("Here is my connecting string");
SqlCommand myCommand = new SqlCommand("SELECT * FROM [Information] ORDER BY (Перевозчик)", sqlConnection);
sqlConnection.Open();
myCommand.ExecuteNonQuery();
}
As found here: https://www.w3schools.com/sql/sql_orderby.asp
Sine we don't know what you want to oder we can only guess here.
But with the query you could try:
SELECT column1, column2, ...
FROM table_name
ORDER BY column1, column2, ... ASC
In your case:
"SELECT * FROM [Information] ORDER BY (Перевозчик) ASC"
Best would be to use the visual query builder where you can query against your database. When you are happy with your result you can at least be sure that the query is correct.
How you can do that is explained here:
https://www.c-sharpcorner.com/article/connect-to-a-database-from-visual-studio/
Since the sqlconnection and the sqlcommand is disposable you should consider putting it in a using tag, like in this example.
https://learn.microsoft.com/en-us/dotnet/api/system.data.sqlclient.sqlcommand?view=netframework-4.8
private static void ReadOrderData(string connectionString)
{
string queryString =
"SELECT OrderID, CustomerID FROM dbo.Orders;";
using (SqlConnection connection = new SqlConnection(
connectionString))
{
SqlCommand command = new SqlCommand(
queryString, connection);
connection.Open();
using(SqlDataReader reader = command.ExecuteReader())
{
while (reader.Read())
{
Console.WriteLine(String.Format("{0}, {1}",
reader[0], reader[1]));
}
}
}
}
There is 2 way for sort data
1) sorting just data and fill into grid:
DataGridView datagridview1 = new DataGridView(); // for show data
DataTable dt1 = new DataTable(); // have data
DataTable dt2 = new DataTable(); // temp data table
DataRow[] dra = dt1.Select("", "ID DESC");
if (dra.Length > 0)
dt2 = dra.CopyToDataTable();
datagridview1.DataSource = dt2;
2) sort default view that is like of sort with grid column header:
DataGridView datagridview1 = new DataGridView(); // for show data
DataTable dt1 = new DataTable(); // have data
dt1.DefaultView.Sort = "ID DESC";
datagridview1.DataSource = dt1;
I found this solution here:
Sorting rows in a data table
For a listbox you could give this a shot
ArrayList q = new ArrayList();
foreach (object o in listBox4.Items)
q.Add(o);
}
q.Sort();
listBox5.Items.Clear();
foreach(object o in q){
listBox5.Items.Add(o);
}
I found this solution here:
Sorting a list of items in a list box
You need to do ExecuteDatareader then process the result coming from this call. ExecuteNonQuery cannot be used to retrieve data.
I'm typically used to traditional table in SQL where I have multiple columns with rows populated. I execute a stored procedure and store all the data in DataTable and loop through the table to get the results I need. For example,
public static DataTable getInfo (string sessionID)
{
try
{
SqlConnection conn = new SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["SandBox"].ConnectionString);
SqlCommand cmd = new SqlCommand("GetSessionInfo", conn);
cmd.Parameters.AddWithValue("SessionGUID", sessionID);
cmd.CommandType = CommandType.StoredProcedure;
DataTable dt = new DataTable();
SqlDataAdapter da = new SqlDataAdapter(cmd);
da.Fill(dt);
return dt;
}
catch (Exception)
{
throw;
}
}
I would load the DataTable:
DataTable infoTbl = new DataTable();
infoTbl = getInfo(lbldatabasesessionID.Text);
And I would use foreach loop to loop through the DataTable.
foreach (DataRow row in infoTbl.Rows)
{
string x = col.ToString();
}
The issue I run into is the database guy gave me a stored procedure that returns a different output (different from what I'm used to). It's a row based.
The only way I can access for example the First Name is if I hard code the position like:
string firstName = infoTbl.Rows[16][2].ToString();
I don't feel comfortable doing this since the position could potentially change. How would I access ElementValue by knowing the name knowing ElementType and ElementName?
Any suggestions?
Using DataSet:
string firstName = string.Empty;
DataRow row = table.Select("ElementType = 'Demographics' AND ElementName = 'FirstName'").FirstOrDefault();
if (row != null)
{
firstName = (string)row["ElementValue"];
}
Using Linq:
string firstName = table.AsEnumerable()
.Where(f => f.Field<string>("ElementType") == "Demographics" &&
f.Field<string>("ElementName") == "FirstName")
.Select(f => f.Field<string>("ElementValue")).FirstOrDefault();
Now I use method in C# to read table from SQLite database into DataTable,
but I want to send all table into other object.
So I think I have to use DataSet to combine all DataTable(s)
and send it to object as parameter.
Is there method that easy read all tables from SQLite database to DataSet?
Or I have to read all tables from SQLite database to DataTable each table
and combine to DataSet by hand?
The sql for listing all the tables is:
SELECT name FROM sqlite_master WHERE type = 'table' ORDER BY 1
you could then get all the tables as databases seperately and then add them into a dataset - an example here: http://www.dotnetperls.com/dataset
so i guess the code would be something like:
Dataset d = new Dataset()
foreach (tableName in GetTables()){
d.Tables.Add(GetDataTable("select * from "+tableName);
}
code for GetTables and GetDataTable (i'll leave the piecing it together to you):
public ArrayList GetTables()
{
ArrayList list = new ArrayList();
// executes query that select names of all tables in master table of the database
String query = "SELECT name FROM sqlite_master " +
"WHERE type = 'table'" +
"ORDER BY 1";
try
{
DataTable table = GetDataTable(query);
// Return all table names in the ArrayList
foreach (DataRow row in table.Rows)
{
list.Add(row.ItemArray[0].ToString());
}
}
catch (Exception e)
{
Console.WriteLine(e.Message);
}
return list;
}
public DataTable GetDataTable(string sql)
{
try
{
DataTable dt = new DataTable();
using (var c = new SQLiteConnection(dbConnection))
{
c.Open();
using (SQLiteCommand cmd = new SQLiteCommand(sql, c))
{
using (SQLiteDataReader rdr = cmd.ExecuteReader())
{
dt.Load(rdr);
return dt;
}
}
}
}
catch (Exception e)
{
Console.WriteLine(e.Message);
return null;
}
}
I am trying to query or match user input against a dataset using a DataTable:
I am populating the dataset from a stored procedure which selects only a single column from a single table: Example: UserID Column. **I am not selecting the entire content of the table.*
public static DataSet LoadProfile()
{
SqlCommand cmdSQL = new SqlCommand("usp_LoadProfile", ConnectDatabase);
cmdSQL.CommandType = CommandType.StoredProcedure;
SqlDataAdapter daSQL = new SqlDataAdapter(cmdSQL);
DataSet ds = new DataSet();
daSQL.Fill(ds);
try
{
ConnectDatabase.Open();
cmdSQL.ExecuteNonQuery();
}
catch(Exception)
{
StatusMsg = ex.Message;
}
finally
{
ConnectDatabase.Close();
cmdSQL.Parameters.Clear();
cmdSQL.Dispose();
}
return ds;
}
I have the following method called in the form load event: I need to populate the dataset on from load.
public static DataTable LoadData()
{
DataSet dsView = new DataSet();
dsView = LoadProfile();
DataTable tblExample = dsView.Tables["Example"];
return tblExample;
}
Finally what I would like to do is match the user entry from the DataTable.
I have this in button event:
DataRow[] results;
results = LoadData().Select(txtExample.Text);
Beyond this point, I could use a for loop but there is only one record for each person.
I am trying to match the user entry with the dataset via the datatable.
The last line should be
DataRow[] results;
results = LoadData().Select("UserID = '" + txtExample.Text +"'");
Supposing that UserID is a field of text type. If instead is of numeric type then remove the quotes
results = LoadData().Select("UserID = " + txtExample.Text);
However I should point that the code in LoadProfile following the daSQL.Fill(ds); call is not needed and you can remove it (just return the DataSet though)
Use the following simple query on dataset:
DataRow[] dRow = dataSetName.Tables[0].Select("fieldToMatch = '" + userInput.ToString() + "' ");
I'm looking at the example here:
http://msdn.microsoft.com/en-US/library/y06xa2h1(v=vs.80).aspx
string s = "primaryKeyValue";
DataRow foundRow = dataSet1.Tables["AnyTable"].Rows.Find(s);
if (foundRow != null)
{
MessageBox.Show(foundRow[1].ToString());
}
else
{
MessageBox.Show("A row with the primary key of " + s + " could not be found");
}
They don't specify where does dataSet1 come from and does this represent some database?
I'm trying to use this example in my code to find unique rows but I can't seem to implement this syntax. I'm only using connection string to open connection to SQL and I use SqlDataAdapter to perform functions...
EDIT:
SqlConnection myConnection = new SqlConnection("Data Source=server; Initial Catalog=Dashboard; Integrated Security=SSPI; Persist Security Info=false; Trusted_Connection=Yes");
SqlDataAdapter da = new SqlDataAdapter();
try
{
//Opens the connection to the specified database
myConnection.Open();
//Specifies where the Table in the database where the data will be entered and the columns used
da.InsertCommand = new SqlCommand("INSERT INTO DashboardLibAnswer(Id,Date,Time,Question,Details,Answer,Notes,EnteredBy,WhereReceived,QuestionType,AnswerMethod,TransactionDuration)"
+ "VALUES(#Id,#Date,#Time,#Question,#Details,#Answer,#Notes,#EnteredBy,#WhereReceived,#QuestionType,#AnswerMethod,#TransactionDuration)", myConnection);
//Specifies the columns and their variable type where the data will be entered
//Special note: Conversion from String > DateTime will cause exceptions that will only import some part of data and not everything
da.InsertCommand.Parameters.Add("#Id", SqlDbType.NVarChar);
da.InsertCommand.Parameters.Add("#Date", SqlDbType.Text);
da.InsertCommand.Parameters.Add("#Time", SqlDbType.Text);
da.InsertCommand.Parameters.Add("#Question", SqlDbType.Text);
da.InsertCommand.Parameters.Add("#Details", SqlDbType.Text);
da.InsertCommand.Parameters.Add("#Answer", SqlDbType.Text);
da.InsertCommand.Parameters.Add("#Notes", SqlDbType.Text);
da.InsertCommand.Parameters.Add("#EnteredBy", SqlDbType.NVarChar);
da.InsertCommand.Parameters.Add("#WhereReceived", SqlDbType.NVarChar);
da.InsertCommand.Parameters.Add("#QuestionType", SqlDbType.NVarChar);
da.InsertCommand.Parameters.Add("#AnswerMethod", SqlDbType.NVarChar);
da.InsertCommand.Parameters.Add("#TransactionDuration", SqlDbType.NVarChar);
//Using the global variable counter this loop will go through each valid entry and insert it into the specifed database/table
for (int i = 0; i < counter; i++)
{
//Iterates through the collection array starting at first index and going through until the end
//and inserting each element into our SQL Table
DataSet dashboardDS = new DataSet();
da.Fill(dashboardDS, "DashboardLibAnswer");
DataTable dt = dashboardDS.Tables["DashboardLibAnswer"];
foreach (DataColumn col in dt.Columns)
{
if (col.Unique)
{
da.InsertCommand.Parameters["#Id"].Value = collection.getIdItems(i);
da.InsertCommand.Parameters["#Date"].Value = collection.getDateItems(i);
da.InsertCommand.Parameters["#Time"].Value = collection.getTimeItems(i);
da.InsertCommand.Parameters["#Question"].Value = collection.getQuestionItems(i);
da.InsertCommand.Parameters["#Details"].Value = collection.getDetailsItems(i);
da.InsertCommand.Parameters["#Answer"].Value = collection.getAnswerItems(i);
da.InsertCommand.Parameters["#Notes"].Value = collection.getNotesItems(i);
da.InsertCommand.Parameters["#EnteredBy"].Value = collection.getEnteredByItems(i);
da.InsertCommand.Parameters["#WhereReceived"].Value = collection.getWhereItems(i);
da.InsertCommand.Parameters["#QuestionType"].Value = collection.getQuestionTypeItems(i);
da.InsertCommand.Parameters["#AnswerMethod"].Value = collection.getAnswerMethodItems(i);
da.InsertCommand.Parameters["#TransactionDuration"].Value = collection.getTransactionItems(i);
da.InsertCommand.ExecuteNonQuery();
}
}
//Updates the progress bar using the i in addition to 1
_worker.ReportProgress(i + 1);
} // end for
//Once the importing is done it will show the appropriate message
MessageBox.Show("Finished Importing");
} // end try
catch (Exception exceptionError)
{
//To show exceptions thrown just uncomment bellow line
//rtbOutput.AppendText(exceptionError.ToString);
} // end catch
//Closes the SQL connection after importing is done
myConnection.Close();
}
if you populate a dataset from your data adapter, you'll be able to follow the same logic -
http://msdn.microsoft.com/en-us/library/bh8kx08z(v=vs.71).aspx
It might be worth showing what you actually have to get more specific help
EDIT
I think I'm understanding what you want - if you fill your datatable from the already populated table, just check the item doesn't already exist before adding it - i.e.
if (dt.Rows.Find(collection.getIdItems(i)) == null)
{
// add your new row
}
(just to be sure I knocked together a quick test - hopefully this helps):
// MyContacts db has a table Person with primary key (ID) - 3 rows - IDs 4,5,6
SqlConnection myConnection = new SqlConnection("Data Source=.; Initial Catalog=MyContacts; Integrated Security=SSPI; Persist Security Info=false; Trusted_Connection=Yes");
SqlDataAdapter da = new SqlDataAdapter();
da.SelectCommand = new SqlCommand("select * from Person", myConnection);
myConnection.Open();
DataSet dashboardDS = new DataSet();
da.Fill(dashboardDS, "Person");
dashboardDS.Tables[0].PrimaryKey = new[] { dashboardDS.Tables[0].Columns["ID"]};
List<int> ids = new List<int> {4, 6, 7};
foreach (var id in ids)
{
if (dashboardDS.Tables[0].Rows.Find(id) == null)
{
Console.WriteLine("id not in database {0}", id); //i.e. 7
}
}
You will first need to open a connection to your database. This is an excellent source for connection strings: The Connection String Reference.
Then you will need to fill the dataset with data from some table. Since we are only interested in the schema information we are only selecting one row (SELECT TOP 1 ...).
Then we can go through the columns and check their Unique property (Boolean):
string connString =
"server=(local)\\SQLEXPRESS;database=MyDatabase;Integrated Security=SSPI";
string sql = #"SELECT TOP 1 * FROM AnyTable";
using (SqlConnection conn = new SqlConnection(connString)) {
conn.Open();
SqlDataAdapter da = new SqlDataAdapter(sql, conn);
using (DataSet ds = new DataSet()) {
da.Fill(ds, "AnyTable");
DataTable dt = ds.Tables["AnyTable"];
foreach (DataColumn col in dt.Columns) {
if (col.Unique) {
Console.WriteLine("Column {0} is unique.", col.ColumnName);
}
}
}
}
UPDATE #1
Sorry, I missunderstood your question. The above example returns unique columns, not unique rows. You can get unique (distinct) rows by using the DISTINCT keyword in SQL:
SELECT DISTINCT field1, field2, field3 FROM AnyTable
You can then fill the data table the same way as above.
Usually the word "unique" is used for unique constraints and unique indexes in database jargon. The term "distinct" is used for rows which are different.
UPDATE #2
Your updated question seems to suggest that you don't want find unique rows, but that you want to insert unique rows (which is the exact opposite).
Usually you would select distinct items from a collection like this. However it is difficult to answer your question accurately, since we don't know the type of your collection.
foreach (var item in collection.Distinct()) {
}
UPDATE #3
The easiest way to insert distinct values in the SQL Server table is to filter the rows at their origin, when reading them from the CSV-File; even before splitting them.
string[] lines = File.ReadAllLines(#"C:\Data\MyData.csv");
string[][] splittedLines = lines
.Distinct()
.Select(s => s.Split(','))
.ToArray();
Now you have distinct (unique) splitted lines that you can insert into the SQL Server table.