I am updating the sql server 2005 database using batch update, as shown below
cmd = new SqlCommand("update Table1 set column1 = #column1 where EmpNo = #EmpNo", con);
cmd.Parameters.Add(new SqlParameter("#column1", SqlDbType.VarChar));
cmd.Parameters["#column1"].SourceVersion = DataRowVersion.Current;
cmd.Parameters["#column1"].SourceColumn = "Column";
cmd.Parameters.Add(new SqlParameter("#EmpNo", SqlDbType.Int));
cmd.Parameters["#EmpNo"].SourceVersion = DataRowVersion.Current;
cmd.Parameters["#EmpNo"].SourceColumn = "EmpNo";
cmd.UpdatedRowSource = UpdateRowSource.None;
sqlDa = new SqlDataAdapter();
con.Open();
sqlDa.UpdateCommand =cmd;
sqlDa.UpdateBatchSize = 10;
sqlDa.Update(dt);
con.Close();
But the data is not updated.I am unable to figure out what is the problem.Any help is appreciated.
I would suggest that you look at the dt right before you issue the update command. Make sure there are some rows that have RowState of Updated or Added. If not, there's nothing in your (I'm assuming) DataTable to update to the database.
Also, try removing the .SourceVersion property set operation.
If everything looks good, start a trace on the database right before you issue the .Update.
These are just a couple first steps to try.
SqlDataAdapter approach
using (SqlCommand insertCommand=new SqlCommand(
"INSERT BulkLoadTable(FieldA, FieldB) VALUES (#FieldA, #FieldB)", connection))
{
insertCommand.Parameters.Add("#FieldA", SqlDbType.VarChar, 10, "FieldA");
insertCommand.Parameters.Add("#FieldB", SqlDbType.Int, 4, "FieldB");
// Setting UpdatedRowSource is important if you want to batch up the inserts
insertCommand.UpdatedRowSource = UpdateRowSource.None;
using (SqlDataAdapter insertAdapter = new SqlDataAdapter())
{
insertAdapter.InsertCommand = insertCommand;
// How many records to send to the database in one go (all of them)
insertAdapter.UpdateBatchSize = myDataTable.Rows.Count;
// Send the inserts to the database
insertAdapter.Update(myDataTable);
}
}
Related
I save changes from my Datatableobject DT1 to my Access database, as can be seen in the following code. My problem is that I always have to run the last executing command a second time. Somehow it doesn't run correctly when run once. I have now fixed the problem in this way, but I would like to understand why that is. Does somebody has any idea?
Kind regards
foreach (DataRow DR1 in DT1.Rows)
{
if (DR1.RowState == DataRowState.Modified | DR1.RowState == DataRowState.Added | DR1.RowState == DataRowState.Deleted)
{
DA1.UpdateCommand = new OleDbCommand("UPDATE Table1 SET Column1 = #Column1, Column2 = #Column2 WHERE ID = #ID", Connection);
DA1.UpdateCommand.Parameters.Add("#Column1", OleDbType.VarChar).Value = DR1["Column1"];
DA1.UpdateCommand.Parameters.Add("#Column2 ", OleDbType.VarChar).Value = DR1["Column2 "];
DA1.UpdateCommand.Parameters.Add("#ID", OleDbType.VarChar).Value = DR1["ID"];
DA1.UpdateCommand.ExecuteNonQuery();
}
DA1.UpdateCommand.ExecuteNonQuery(); // Without this, the last command will not be executed
}
I am searching for (PostId,UserId) into PostLikes table using SqlDataAdapter, if the row is found , I am using SqlCommandBuilder.GetDeleteCommand() to generate the delete instruction and deleting the underlying row, if the row is not found, then I use SqlCommandBuilder.GetInsertCommand() to generate the insert command and inserting the row to the table using SqlDataAdapter.Update(). But the row is not getting inserted to the table in database. Here is what I have done so far
SqlConnection con = new SqlConnection(connectionStrings);
SqlDataAdapter sqlDataAdapter=new SqlDataAdapter("select * from PostLikes where PostId like "
+postlike.PostId+" and UserId like "
+postlike.UserId,con);
DataSet ds = new DataSet();
sqlDataAdapter.Fill(ds, "Result");
con.Open();
SqlCommandBuilder sqlCommandBuilder = new SqlCommandBuilder(sqlDataAdapter);
if(ds.Tables["Result"].Rows.Count==1)
{
sqlDataAdapter.DeleteCommand = sqlCommandBuilder.GetDeleteCommand(true);
msg = "Data is deleted";
}
else
{
sqlDataAdapter.InsertCommand = sqlCommandBuilder.GetInsertCommand(true);
msg = "Data is inserted";
}
sqlDataAdapter.Update(ds, "Result");
and the tablePostLikes(LikeId,PostId,UserId)
There are a couple of issues:
You are looking to reuse the same command to both detect whether the row exists, and to supply to the SqlAdapter for the SqlCommandBuilder.
You should parameterise the initial select query to protect against SqlInjection attacks (and there is a minor performance benefit). The CommandBuilder will automatically parameterize the Insert / Delete commands
After creating the Insert / Delete commands with the SqlCommandBuilder, you then need to change the underlying dataset in order for any changes to be made to the table during the Update.
Note that many of the Sql objects are IDisposable and should be disposed ASAP - using scopes help here.
.
var postId = 1;
var userId = 1;
string msg;
using (var con = new SqlConnection(#"data source=..."))
using (var selectCommand = new SqlCommand(
"select LikeId, PostId, UserId from PostLikes WHERE PostId=#PostId AND UserId=#UserId", con))
using (var sqlDataAdapter = new SqlDataAdapter(selectCommand))
using (var ds = new DataSet())
{
con.Open();
selectCommand.Parameters.AddWithValue("#PostId", postId);
selectCommand.Parameters.AddWithValue("#UserId", userId);
sqlDataAdapter.Fill(ds, "Result");
using (var sqlCommandBuilder = new SqlCommandBuilder(sqlDataAdapter))
{
if (ds.Tables["Result"].Rows.Count == 1)
{
sqlDataAdapter.DeleteCommand = sqlCommandBuilder.GetDeleteCommand(true);
ds.Tables["Result"].Rows[0].Delete();
msg = "Data will be deleted";
}
else
{
sqlDataAdapter.InsertCommand = sqlCommandBuilder.GetInsertCommand(true);
// Null because LikeId is Identity and will be auto inserted
ds.Tables["Result"].Rows.Add(null, postId, userId);
msg = "Data will be inserted";
}
sqlDataAdapter.Update(ds, "Result");
}
}
I've assumed the following Schema:
CREATE TABLE PostLikes
(
LikeId INT IDENTITY(1,1) PRIMARY KEY,
PostId INT,
UserId INT
)
And I've assumed you want to 'toggle' the insertion or deletion of a row with the postId, userid combination.
I'm trying to read data from files and to use bulk copy to insert it in the database table.
When I try to run my code, I get the error: "Cannot Access Denstination Table"
Declaration of FlatTable.
System.Data.DataTable flatTableTempData = new System.Data.DataTable("FlatTable");
DataColumn DistrictColumn = new DataColumn();
DistrictColumn.ColumnName = "DistrictName";
// Create Column 3: TotalSales
DataColumn TownColumn = new DataColumn();
TownColumn.ColumnName = "TownName";
DataColumn FarmerColumn = new DataColumn();
FarmerColumn.ColumnName = "FarmerName";
flatTableTempData.Columns.Add(DistrictColumn);
flatTableTempData.Columns.Add(TownColumn);
flatTableTempData.Columns.Add(FarmerColumn);
This is my code, with the connection string and the insertion using bulk copy:
using (SqlConnection con = new SqlConnection("Data Source=DRTARIQ-PC\\SQLEXPRESS;Integrated Security=SSPI;Initial Catalog=TestDB2"))
{
con.Open();
using (SqlBulkCopy s = new SqlBulkCopy(con))
{
s.DestinationTableName = flatTableTempData.TableName;
foreach (var column in flatTableTempData.Columns)
s.ColumnMappings.Add(column.ToString(), column.ToString());
s.BulkCopyTimeout = 500;
s.WriteToServer(flatTableTempData);
}
}
I've encountered the same problem. The table exists, the SQL user has access but SqlBulkCopy cannot access the table. My problem turned out to be I turned off the indexing to try and insert faster (rebuild index after the bulkcopy), but this made the table inaccessible. After I turned the indexing on again it worked, SqlBulkCopy has access to the table.
The table name in WriteToServer method of SqlBulkCopy must be surrounded with [ ] signs.
Below is the code for my Select * Function - It WORKS well and does everything great until i change the SQL string from Select * From Company to
query = "Select * From #1";
and then do the following
query = "Select * From #1";
OleDbCommand Command = new OleDbCommand(query, sqlConnStr);
DataTable Table = new DataTable();
DataSet dataSet = new DataSet();
Table = null;
//Add Parameters
Command.Parameters.AddWithValue("#1", SQLTables.Company);
try
{
Command.ExecuteNonQuery();
adapter.SelectCommand = Command;
adapter.Fill(dataSet);
Table = dataSet.Tables[0];
}
catch (Exception e)
{
MessageBox.Show("A Error occured whilst trying to execute the command.\n" + e.Message);
}
return Table;
The DBMS keeps sending back "Query incomplete" - I assume The Command variable is sending the string query through without changing the Parameter from #1 to Company
Here is a piece of code (mine) where this does work. This is an insert statement rather that a select - Correct me if i am wrong but should it not also work with the SELECT aswell
private void MainActionsInsert(string Action, bool Checked)
{
OleDbCommand Command = new OleDbCommand("INSERT INTO MainActions Values (ID, Action, BoolValue)", DataBaseConnection);
//Add Parameters
Command.Parameters.AddWithValue("ID", GenerateID());
Command.Parameters.AddWithValue("Action", Action);
Command.Parameters.AddWithValue("BoolValue",Checked);
//Add Command
MainActionsAdapter.InsertCommand = Command;
//Execute Agains DataBase
Command.ExecuteNonQuery();
//Accept Changes
}
`
OLEdb doesn't recognize named parameters. You must use ? in the query text.
However, you also can't use dynamic table names with parameterized queries, so even using a ? will not help.
You need to use full dynamic SQL, though that can open you up to SQL Injection. Make sure you read the full article I linked.
OleDbCommand Does accept Parameterized SQL just not in the From Clause - It Has to be either in a WHERE clause or something like that. Like you said it Worked with the insert function because it expects "parameters" there. For example this will work
query = "Select * From Company Where #param = 1";
OleDbCommand Command = new OleDbCommand(query, sqlConnStr);
DataTable Table = new DataTable();
DataSet dataSet = new DataSet();
Table = null;
//Add Parameters
Command.Parameters.AddWithValue("param", "ID");
try
{
Command.ExecuteNonQuery();
adapter.SelectCommand = Command;
adapter.Fill(dataSet);
Table = dataSet.Tables[0];
}
catch (Exception e)
{
MessageBox.Show("A Error occured whilst trying to execute the command.\n" + e.Message);
}
return Table;
Funny though that it doesn't work for the Select part though
Consider the following code:
StringBuilder textResults = new StringBuilder();
using(SqlConnection connection = new SqlConnection(GetEntityConnectionString()))
{
connection.Open();
m.Connection = connection;
SqlDataReader results = m.ExecuteReader();
while (results.Read())
{
textResults.Append(String.Format("{0}", results[0]));
}
}
I used Activity Monitor within Sql Server Mgmt Studio on the database to inspect the exact query that was being sent. I then copied that query text to a query editor window within SSMS, and the query returned the expected results. However, SqlDataReader results is always empty, indicating "The enumeration returned no results."
My suspicion is that somehow the results are not being returned correctly, which makes me think there's something wrong with the code above, and not the query itself being passed.
Is there anything that would cause this in the code above? Or something I've overlooked?
EDIT:
Here is the query as indicated by the SQLCommand object:
SELECT DISTINCT StandardId,Number
FROM vStandardsAndRequirements
WHERE StandardId IN ('#param1','#param2','#param3')
ORDER BY StandardId
Here is the query as it appears in Activity Monitor:
SELECT DISTINCT StandardId,Number
FROM vStandardsAndRequirements
WHERE StandardId IN ('ABC-001-0','ABC-001-0.1','ABC-001-0')
ORDER BY StandardId
The query is working against a single view.
When I ran the second query against the database, it returned 3 rows.
The SqlDataReader indicates 0 rows.
try to use Sqldata adapter instead of sqldatreader.
StringBuilder textResults = new StringBuilder();
using (var conn = new SqlConnection(GetEntityConnectionString())))
{
using (
var cmd = new SqlCommand(
"SELECT DISTINCT StandardId,Number" +
"FROM vStandardsAndRequirements " +
"WHERE StandardId IN (#param1,#param2,#param3)" +
"ORDER BY StandardIdl"
, conn))
{
var dSet = new DataSet();
var dt = new Datatable();
var da = new SqlDataAdapter(cmd);
cmd.Parameters.Add("#param1", SqlDbType.VarChar, 50).Value = "ABC-001-0";
cmd.Parameters.Add("#param2", SqlDbType.VarChar, 50).Value = "ABC-001-0.1";
cmd.Parameters.Add("#param3", SqlDbType.VarChar, 50).Value = "ABC-001-0";
try
{
da.Fill(dSet);
dt = dSet.Tables[0];
foreach(Datarow a in dt.Rows)
{
textResults.Append(a["StandardId"].tostring()).AppendLine();
}
Messabox.Show(textResults.tostring);
}
catch (SqlException)
{
throw;
}
finally
{
if (conn.State == ConnectionState.Open) conn.Close();
}
}
}
Regards.
Are you sure it is
WHERE StandardId IN ('#param1','#param2','#param3')
instead of this?
WHERE StandardId IN (#param1,#param2,#param3)
Parameters should not be quoted, not in the SQLCommand object.
Very nice behavior I've observed
I looked for errors in code:
... dr = command.ExecuteReader() ... If dr.Read Then ...
and found that 'dr.Read' works fine, but...
when I mouseover on 'dr', to lookup for data, return values disappeared !
Check your connection string and make sure you are not connecting as a user instance.
http://msdn.microsoft.com/en-us/library/ms254504.aspx