I'm having trouble selecting all items from my access database. I want to select the data in the entire row and keep it in a string, separating each item by a ";". Below is the code i have that will give me the column i specify, but i want all the data in the row.
con.Open();
type= checkBox49.Text;
String str = "Select * from distro where type='" + type + "'";
cmd = new OleDbCommand(str, con);
dr = cmd.ExecuteReader();
if (dr.Read())
{
str2 = dr.GetString(1);
}
You can try something like this where columnsCount is the number of your columns in your database table
if (dr.Read())
{
for (int i = 0; i <columnsCount; i++)
{
str2 += string.Join(";",sdr.GetString(i));
}
}
You could select each field by name and combine them together like
str2 = dr["FieldName"].ToString() + "." + dr["FieldName"].ToString();
Also, I wouldn't reference any fields by number, but by FieldName.
So one approach, with the current code, would be this:
StringBuilder sb = new StringBuilder();
if (dr.Read())
{
for (int i = 0; i < dr.FieldCount; i++)
{
if (sb.Length > 0) { sb.Append(";"); }
sb.Append(dr.GetString(i));
}
}
A more global code if all your columns are not string type :
var con = new OleDbConnection();
var cmd = new OleDbCommand(str, con);
var dr = cmd.ExecuteReader();
var res = string.Empty;
if (dr.Read())
{
object[] t = new Object[dr.FieldCount];
if (dr.GetValues(t)>0)
{
res = String.Join(";", (from el in t select el as string).Where(x => x!=null).ToArray());
}
}
return res;
You could just string.Join all the values together.
con.Open();
type = checkBox49.Text;
String str = "Select * from distro where type=?";
cmd = new OleDbCommand(str, con);
cmd.Parameters.Add(type);
using (dr = cmd.ExecuteReader())
{
if (dr.Read())
{
var values = new object[dr.FieldCount];
dr.GetValues(values);
str2 = string.Join(";", values.Skip(1).Select(d => d.ToString());
}
}
Notice the use of a parameter in the query too. Standard way to avoid SQL Injection.
Related
My code isn't returning any rows from a test database table when I pass a string version of a list, but it does return rows if I pass the list members in directly.
When I use a message box to show the string joinedSerialsList, it appears to be formatted properly.
// Create comma delimited list of serials:
int currentSerial = beginning;
List<string> serialsList = new List<string>();
for (int i = 0; i < count; i++)
{
serialsList.Add(currentSerial.ToString());
currentSerial++;
}
string joinedSerialsList = string.Format("({0})", string.Join(", ", serialsList));
OleDbConnection connection = BadgeDatabaseDB.GetConnection();
string checkStatement
= "SELECT SerialNumber, OrderNumber "
+ "FROM SerialNumbersMFG "
+ "WHERE SerialNumber IN (#List)";
OleDbCommand command = new OleDbCommand(checkStatement, connection);
command.Parameters.AddWithValue("#List", joinedSerialsList);
string duplicateSerials = "";
try
{
connection.Open();
OleDbDataReader dataReader = command.ExecuteReader();
if (dataReader.Read())
{
duplicateSerials += dataReader["OrderNumber"].ToString() + "\n";
}
}
catch (OleDbException ex)
{
throw ex;
}
finally
{
connection.Close();
}
return duplicateSerials;
I rewrited your sample, this work:
private IEnumerable<string> getData()
{
// Create comma delimited list of serials:
int currentSerial = 4452; // your constant
var serialsList = new List<int>();
var count = 100;
for (int i = 0; i < count; i++)
serialsList.Add(currentSerial++);
var connString = getConnectionString();
var results = new List<string>();
string sqlSelect = $"SELECT SerialNumber, OrderNumber FROM SerialNumbersMFG WHERE SerialNumber IN ({string.Join(",", serialsList)})";
using (var connection = new SqlConnection(connString)) // BadgeDatabaseDB.GetConnection();
{
using (var command = new SqlCommand(sqlSelect, connection))
{
connection.Open();
var dataReader = command.ExecuteReader();
while (dataReader.Read())
results.Add(dataReader["OrderNumber"].ToString());
}
}
return results;
}
Have the error 'dbConn.ServerVersion' threw an exception of type 'System.InvalidOperationException, however VisualStudio does not pause the program and throw the exception at me. Here is the code:private void BTN_NA_Click(object sender, EventArgs e)
{
if (TXT_NAUN.Text != "" && TXT_NAPW.Text != "" && TXT_NAPW2.Text != "")
{
if (TXT_NAPW.Text == TXT_NAPW2.Text)
{
string input = TXT_NAPW.Text;
int hash = 0;
int output = 0;
foreach (char chara in input)
{
int temp = 0;
temp = System.Convert.ToInt32(chara);
output = output + temp;
output = output * 2;
}
hash = output % 1000;
OleDbConnection dbConn = new System.Data.OleDb.OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=BHShooterProjectDB.accdb");
string sql = "SELECT Accounts.PlayerID FROM Accounts ORDER BY Accounts.PlayerID DESC ";
///string comm = "SELECT Accounts.PlayerID from Accounts";
/// INNER JOIN Leaderboard ON Leaderboard.PlayerID = Accounts.PlayerID WHERE Accounts.PlayerUsername = #ip";
OleDbCommand cmd = new OleDbCommand(sql, dbConn);
string result = "";
dbConn.Open();
OleDbDataReader reader = cmd.ExecuteReader();
while (reader.Read())
{
result = reader[0].ToString();
}
dbConn.Close();
{
string comm = "INSERT INTO Accounts (PlayerUsername, PlayerPassword, PlayerID, PlayerInvID) VALUES (#NAUN, #HPW, #NAPI, #NAPI)";
OleDbCommand command = new OleDbCommand(comm, dbConn);
command.Parameters.AddWithValue("#NAUN", TXT_NAUN.Text);
command.Parameters.AddWithValue("#HPW", hash);
foreach (char chara in result)
{
int temp = 0;
temp = System.Convert.ToInt32(chara);
result = result + temp;
}
result = result + 1;
command.Parameters.AddWithValue("#NAPI", result);
command.Parameters.AddWithValue("#NAPI", result);
dbConn.Open();
int rowsAffected = cmd.ExecuteNonQuery(); ///error appears here
dbConn.Close();
}
}
}
}
Any suggestions on solution, have tried a lot and this is my last hope!
Thanks,
Blackclaw_
At the line you got the error, you are using cmd (the select command). I think you want to use command (the insert command).
I have a string array which consists of identifiers. I want to get some values from SQL using these identifiers . Is there a way of adding them with a string value to SqlCommand parameters?
I want to create a query like:
select CaseList from MasterReportData where Id = 1 OR Id = 2 OR Id = 3
This is my C# code:
public static List<string> GetCaseList(string[] masterIdList)
{
try
{
string query = " select CaseList from MasterReportData where #masterId";
SqlConnection conn = new SqlConnection(connString);
SqlCommand cmd = new SqlCommand(query, conn);
cmd.Parameters.AddWithValue("masterId", ***);
conn.Open();
using (SqlDataReader reader = cmd.ExecuteReader())
{
while (reader.Read())
{
list.Add(reader[0].ToString());
}
}
conn.Close();
}
catch (Exception e)
{
var err= 0;
}
return list;
}
There are many different ways you can go about doing this but I prefer to create a temp table of possible values. That way you can do something like
select CaseList from MasterReportData where Id IN(select Id from tempTable)
The best approach (with sql optimization) would be:
Create your Type:
CREATE TYPE dbo.IntTTV AS TABLE
( Id int )
Your Ids:
var ids = new List<int>
{
1,
2,
3,
}
Create a schema:
var tableSchema = new List<SqlMetaData>(1)
{
new SqlMetaData("Id", SqlDbType.Int) // I think it's Int
}.ToArray();
Create the table in C#
var table = ids
.Select(i =>
{
var row = new SqlDataRecord(tableSchema);
row.SetInt32(0, i);
return row;
})
.ToList();
Create the SQL Parameter
var parameter = new SqlParameter();
parameter.SqlDbType = SqlDbType.Structured;
parameter.ParameterName = "#Ids";
parameter.Value = table;
parameter.TypeName = "dbo.IntTTV";
var parameters = new SqlParameter[1]
{
parameter
};
Slightly change your query (this is just an example:)
string query = "select mrd.CaseList from MasterReportData mrd"
+ " inner join #ids i on mrd.Id = i.id";
public static List<string> GetCaseList(string[] masterIdList)
{
List<string> list = new List<string>();
try
{
string query = "select CaseList from MasterReportData where ";
using (SqlConnection conn = new SqlConnection(connString))
{
int i = 0;
SqlCommand cmd = new SqlCommand(query, conn);
for(i = 0; i < masterIdList.Length; i++)
{
var parm = "#ID" + i;
cmd.Parameters.Add(new SqlParameter(parm, masterIdList[i]));
query += (i > 0 ? " OR " : "") + " Id = " + parm;
}
cmd.CommandText = query;
//cmd.Parameters.AddWithValue("masterId", ***);
conn.Open();
using (SqlDataReader reader = cmd.ExecuteReader())
{
while (reader.Read())
{
list.Add(reader[0].ToString());
}
}
}
}
catch (Exception e)
{
e.ToString();
}
return list;
}
I want to get the names associated with the states i select in my program. Below is the code that i currently have. My database has multiple locations within a state that have different contacts. I just want to select a state and acquire everyone under that state. Thanks for the help!
con = new OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=F:\\Database\\LocNo.accdb");
con.Open();
foreach (Object c in checkedListBox2.CheckedItems)
{
if (checkedListBox2.GetItemCheckState(checkedListBox2.Items.IndexOf(c)) == CheckState.Checked)
{
str1 += c.ToString() + ",";
flag = 1;
}
}
i = 0;
allSelectedtypestring = "";
allSelected = str1.Split(',');
while (allSelected.Length - 1 > i)
{
str = "select c1 from table where state ='" + allSelected[i++] + "'";
cmd = new OleDbCommand(str, con);
dr = cmd.ExecuteReader();
dr.Read();
allSelectedtypestring += dr.GetString(11);
}
label30.Text = Convert.ToString(allSelectedtypestring);
con.Close();
You can use the following code to retrieve the contacts:
var states = new List<string>();
foreach (Object c in checkedListBox2.CheckedItems)
{
states.Add(c.ToString());
flag = 1; // Can also be substituted by states.Count > 0
}
using(var con = new OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=F:\\Database\\LocNo.accdb"))
{
con.Open();
using(var cmd = con.CreateCommand())
{
var paramIndex = 0;
var paramClause = new System.Text.StringBuilder(100);
foreach(var state in states)
{
if (paramClause.Length > 0)
paramClause.Append(", ");
paramClause.Append("?");
var paramName = "State" + (paramIndex++).ToString();
cmd.Parameters.AddWithValue(paramName, state);
}
var paramsClause = string.Join(", ", cmd.Parameters.
cmd.CommandText = "select distinct c1 from table where state IN (" + paramsClause.ToString() + ")";
using(var rdr = cmd.ExecuteReader())
{
var contacts = new List<string>();
while(rdr.Read())
{
contacts.Add(rdr.GetString(0);
}
label30.Text = string.Join(", ", contacts);
}
}
}
Please note that I've made the following changes:
Added using statements to reliably dispose the connection, command and reader.
Used a List<string> as a more convenient way to collect the selected states.
Added DISTINCT to the SELECT in order to filter duplicate entries.
Used a parameter in the command text in order to avoid SQL injection attacks. Though this way to use a parameter with an IN clause works for SQL Server, I haven't checked whether it also works for an Access database. Let me know in the comments if it doesn't work.
I was trying to remove duplicates from the table Main.
It looks like this(here in csv form):
"Record ID";Status;Placement;Private;Category;Note;Blob
for instance
14341692;132;2147483647;False;4;"29.12.10 14:17";System.Byte[]
Duplicates means, Note is the same. My approach is this:
string strSQL = "SELECT * FROM Main";
OleDbCommand cmd = new OleDbCommand(strSQL, MemoVerbindung);
OleDbDataReader dr = cmd.ExecuteReader();
_items = new List<string>(); // <-- Add this
while (dr.Read())
{
if (dr.FieldCount >= 5)
_items.Add(dr[5].ToString());
}
dr.Close();
progressBar1.Maximum = _items.Count;
for (int a = 0; a < _items.Count; a++)
{
progressBar1.Value = a;
strSQL = "SELECT * FROM Main WHERE Note = '" + _items[a].ToString().Replace("'", "\'") + "'";
cmd = new OleDbCommand(strSQL, MemoVerbindung);
dr = null;
OleDbDataReader dr2 = null;
try
{
dr = cmd.ExecuteReader();
int u = 0;
if (dr.FieldCount > 1)
{
while (dr.Read())
{
if (u >= 1)
{
string was = "DELETE FROM Main WHERE [Record ID] = " + dr[0];
OleDbCommand command = new OleDbCommand(was, MemoVerbindung);
OleDbDataReader reader = command.ExecuteReader();
while (reader.Read())
{
//MessageBox.Show(reader[0].ToString());
}
reader.Close();
}
u++;
}
}
else
{
while (dr.Read())
{
MessageBox.Show("Übrig");
}
}
dr.Close();
}
catch (Exception mm)
{
//MessageBox.Show(mm.Message);
}
}
MessageBox.Show("Fertig");
progressBar1.Value = 0;
So in the if (u >= 1) section I am trying to leave one version while removing all others. Unfortunately that does not work meaning all entries are removed but the ones raising an error for a reason. What would you change or is there a generally more elegant way?
Use this SQL statement to find the duplicates:
SELECT First(Main.[Note]) AS [NoteField], Count(Main.[Note]) AS NumberOfDups
FROM Main
GROUP BY Main.[Note]
HAVING (((Count(Main.[Note]))>1));
then you can loop through this recordset (grab it as a SnapShot so changes to the underlying data does not change the results)
use !NoteField to know which note to find, and !NumberOfDups to know how many you have to delete (remove this number - 1)