I am trying to update a row in MySQL database from within ASP.NET using ASP.NET.
MySqlConnection cnx = new MySqlConnection(con);
MySqlDataAdapter adapter = new MySqlDataAdapter();
DataTable dt = new DataTable();
dt.Columns.Add("id", typeof(Int32) );
dt.Columns.Add("config", typeof(string) );
dt.TableName = "sharding_conf";
DataRow dr = dt.NewRow();
dr["id"] = 1;
dr["config"] = json;
int ok = adapter.Update(dt);
lblTest.Text = ok.ToString();
cnx.Dispose();
adapter.Dispose();
However the row is not getting updated, any suggestions?
Please you done like that ex:
SqlConnection sqlConnection1 = new SqlConnection("Your Connection String");
SqlCommand cmd = new SqlCommand();
cmd.CommandText = "insert into tablename(colname1,columnname2) values(val1,val2)";
cmd.CommandType = CommandType.Text;
cmd.Connection = sqlConnection1;
sqlConnection1.Open();
cmd.ExecuteNonQuey();
sqlConnection1.Close();
I think you are missing mySqlconnection instance as argument in MysqlDataAdapter
if no then try the alternate way using mySqlCommand in which pass your Update query. I know this much only.
and instead of disposing your objects manually use Using Statement.
Refer this link for more understanding.
Related
My application needs to get data from a store procedure. In a query program the stored procedure works fine;
exec MyStoredProdure #Prama1 = '01'
In WPF it times out. Here is my code;
using (SqlConnection con = new SqlConnection(ConString))
{
con.Open();
SqlCommand cmd = new SqlCommand();
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.AddWithValue("#Prama1", "01");
cmd.CommandText = "MyStoredProdure";
cmd.Connection = con;
SqlDataAdapter sda = new SqlDataAdapter(cmd);
DataTable dt = new DataTable("MyStoredProdure");
sda.Fill(dt);
foreach (DataRow dr in dt.Rows)
{
//Do code
}
con.Close();
}
It is timing out right on sda.Fill(dt). It should be noted that Select and inserts work perfectly fine.
I believe you're missing the sda.SelectCommand = cmd; before the fill.
How to use a DataAdapter with stored procedure and parameter
How use WHERE in SqlDataAdapter in C#?
I want get name in a textbox and use that at query but it wont work .
SqlConnection sqlconnection = new SqlConnection("Server=Behnam\\Accounting;Initial Catalog=Accounting;Integrated Security=TRUE");
DataTable dt = new DataTable();
string _search_name = txt_search.Text;
SqlDataAdapter SDA = new SqlDataAdapter("SELECT dbo.tbl_user.field1,dbo.tbl_user.field2 FROM tbl_user WHERE dbo.tbl_user.name=_search_name ", sqlconnection);
SDA.Fill(dt);
dataGridView1.DataSource = dt;
Prepare the command text and use a parameter for the value of your search.
Then use that command text to initialize a new SqlCommand. Fill the parameter value with AddWithValue and pass the SqlCommand to the constructor of the SqlDataAdapter.
string cmdText = "SELECT dbo.tbl_user.field1,dbo.tbl_user.field2 " +
"FROM tbl_user WHERE dbo.tbl_user.name=#search_name"
SqlCommand cmd = new SqlCommand(cmdText, sqlconnection);
cmd.Parameters.AddWithValue("#search_name", _search_name);
SqlDataAdapter SDA = new SqlDataAdapter(cmd);
The SqlDataAdapter will store your command as the SelectCommand property and will use the passed in SqlCommand to execute the query to retrieve the records from the database.
Keep in mind that AddWithValue is a shortcut with some drawbacks. For example it pass Always a string as a nvarchar parameter with size equal to the actual lenght of the variable. This effectively reduces the performance of the Sql Server Optimizer.
This is a very enlightening article on the issue
So, you were pretty close, you just needed to define a parameter inside the query and then add that parameter. However, in the following code block I've also conveniently recommended a more appropriate approach to using the classes needed to get the data (pun intended). The using statement here ensures that the objects get disposed of properly after you are done using them (man I just can't stop with the puns!)
using (SqlConnection c = new SqlConnection(connString))
{
c.Open();
using (SqlDataAdapter sda = new SqlDataAdapter(
"SELECT dbo.tbl_user.field1, dbo.tbl_user.field2 FROM tbl_user " +
"WHERE dbo.tbl_user.name= #name", c))
{
sda.SelectCommand.Parameters.AddWithValue("#name", txt_search.Text);
DataTable dt = new DataTable();
sda.Fill(dt);
}
}
Try this.
you were using the string directly in the query which will go undetected.
SqlConnection sqlconnection = new SqlConnection("Server=Behnam\\Accounting;
Initial Catalog=Accounting;Integrated Security=TRUE");
DataTable dt = new DataTable();
SqlDataAdapter SDA = new SqlDataAdapter("SELECT dbo.tbl_user.field1,dbo.tbl_user.field2 FROM tbl_user WHERE dbo.tbl_user.name=#searchName" , sqlconnection);
SDA.SelectCommand.Parameters.AddWithValue("#searchName", txt_search.Text);
SDA.Fill(dt);
dataGridView1.DataSource = dt;
So i currently have two combo boxes. One Being Manufacture the other being model. My sql query looks like this "Select Distinct Model From sheet1 where (Manufacture =#Manufacture)" this works when i execute it and if i were to fill a datagridtable. But if i try to place this into a combobox i get System.data.d...... etc for my selections. How can i just have it show the values instead of all this. What am i doing wrong?
private void ManuComboBox_SelectedIndexChanged(object sender, EventArgs e)
{
string manu = comboBox3.Text;
string conStr = "Data Source=CA-INVDEV\\RISEDB01;Initial Catalog=RISEDB01; Integrated Security=True";
string sqlcmd = "SELECT DISTINCT Model FROM Sheet1 WHERE (Manufacture =#Manufacture)";
using (SqlConnection conn = new SqlConnection(conStr))
{
SqlCommand cmd = new SqlCommand(sqlcmd, conn);
cmd.Parameters.AddWithValue("#Manufacture", manu);
SqlDataReader dr = cmd.ExecuteReader();
if (dr.HasRows)
{
dr.Close();
SqlDataAdapter dataAdapter = new SqlDataAdapter(cmd);
SqlCommandBuilder commandBuilder = new SqlCommandBuilder(dataAdapter);
DataTable table = new DataTable();
table.Locale = System.Globalization.CultureInfo.InvariantCulture;
dataAdapter.Fill(table);
bindingSource3.DataSource = table;
ModelComboBox.DataSource = bindingSource3;
}
}
}
Can you give this a try?
using (SqlConnection conn = new SqlConnection(conStr))
{
conn.Open();
SqlCommand cmd = new SqlCommand(sqlcmd, conn);
cmd.Parameters.AddWithValue("#Manufacture", manu);
SqlDataReader dr = cmd.ExecuteReader();
IList<string> modelList = new List<string>()
while (dr.Read())
{
modelList.add(dr[0].ToString());
}
ModelComboBox.DataSource = modelList;
}
If you have set the display member like:
ModelComboBox.DataSource = bindingSource3;
ModelComboBox.DisplayMember = "ColumnName";
And it still shows funny values, what are the values that it shows exactly?
Note, in a toolstrip it looks like you may have to also do:
ModelComboBox.BindingContext = this.BindingContext;
here is a reference
Try adding
ComboBox1.ItemsSource = bindingSource3
if this is your answer then mark it as answer
This one is a mystery for me, I know the code I took it from others, in my case the datatable it returns is empty
conSTR is the connection string, set as a global string
public DataTable fillDataTable(string table)
{
string query = "SELECT * FROM dstut.dbo." +table;
SqlConnection sqlConn = new SqlConnection(conSTR);
sqlConn.Open();
SqlCommand cmd = new SqlCommand(query, sqlConn);
DataTable dt = new DataTable();
dt.Load(cmd.ExecuteReader());
sqlConn.Close();
return dt;
}
EDIT 1
The whole point is to later show this table in a datagrid view on a tabcontrol, here is the question on that
displaying multiple datatable in tabcontrol C#
Here it just show's me a blank datagridview
EDIT 2
Tried them all, when I try to display the table, the datagridview is empty, have the right amount of rows but now value
If the variable table contains invalid characters (like a space) you should add square brackets around the variable.
public DataTable fillDataTable(string table)
{
string query = "SELECT * FROM dstut.dbo.[" + table + "]";
using(SqlConnection sqlConn = new SqlConnection(conSTR))
using(SqlCommand cmd = new SqlCommand(query, sqlConn))
{
sqlConn.Open();
DataTable dt = new DataTable();
dt.Load(cmd.ExecuteReader());
return dt;
}
}
By the way, be very careful with this kind of code because is open to Sql Injection. I hope for you that the table name doesn't come from user input
Try with following:
public DataTable fillDataTable(string table)
{
string query = "SELECT * FROM dstut.dbo." +table;
SqlConnection sqlConn = new SqlConnection(conSTR);
sqlConn.Open();
SqlCommand cmd = new SqlCommand(query, sqlConn);
SqlDataAdapter da=new SqlDataAdapter(cmd);
DataTable dt = new DataTable();
da.Fill(dt);
sqlConn.Close();
return dt;
}
Hope it is helpful.
I am facing a little problem in my code to add data to sql database attached with my program in ASP.net/C#. Here's code:
string ConnectionString = System.Configuration.ConfigurationManager.ConnectionStrings["sqlconnection"].ConnectionString;
SqlConnection cnn = new SqlConnection(ConnectionString);
cnn.Open();
SqlCommand cmd = new SqlCommand();
cmd.CommandText = "select Id from TableName";
cmd.Connection = cnn;
SqlDataAdapter da = new SqlDataAdapter();
da.SelectCommand = cmd;
DataSet ds = new DataSet();
da.Fill(ds, " TableName ");
SqlCommandBuilder cb = new SqlCommandBuilder(da);
DataRow drow = ds.Tables["TableName"].NewRow();
drow["Id"] = TextBox1.Text;
ds.Tables["TableName "].Rows.Add(drow);
da.Update(ds, " TableName ");
string script = #"<script language=""javascript"">
alert('Information have been Saved Successfully.......!!!!!.');
</script>;";
Page.ClientScript.RegisterStartupScript(this.GetType(), "myJScript1", script);
Even when I entered any integer value to the text box, it shows an error message that object is not set to an instance on code:
DataRow drow = ds.Tables["TableName"].NewRow();
Please guide.
Thanks.
This seems like a very bad way of inserting data. Have you looked at the Entity Framework or Linq2Sql? Alternatively you could just use a standard SqlCommand and set the CommandText yourself.
Any of these would provide a cleaner solution.
Eg: With ADO.NET (Connecting to SQLite):
var conn = new SQLiteConnection(string.Format(Constants.SQLiteConnectionString, "db.db3"));
conn.Open();
using (SQLiteTransaction trans = conn.BeginTransaction()) {
using (var cmd = conn.CreateCommand()) {
cmd.CommandText = "INSERT INTO TableName (Id) VALUES (#Id)";
cmd.Parameters.AddWithValue("#Id", someTextVariable);
cmd.ExecuteNonQuery();
}
}