LinQ Query help - linq-to-sql

I have added a table(ViolationsDataSourceConfig) to the dbml file.
The context name is ViolationsDataContext.
I am trying to write a function that should return employee object but it is throwing errors. Below is the code. Is there any easy way for achieving this. I just want the ViolationsDataSourceConfig.
Public Shared Function GetDataSourceDetails(ByVal ApplicationID As Integer) As ViolationsDataSourceConfig
Dim _db As New ViolationsDataContext
Dim appSource As New ViolationsDataSourceConfig
Dim application As Table(Of ViolationsDataSourceConfig) = _db.GetTable(Of ViolationsDataSourceConfig)()
Try
appSource = From a In application Where a.ApplicationID = ApplicationID And a.Status = 1 _
Select a
Catch ex As Exception
End Try
Return appSource
End Function

It's a little hard without more information regarding your data structures or the errors you're getting, could you provide the error at least?
Also, you say your LINQ statement should "return employee" but you are typing it as "ViolationsDataSourceConfig", how does that work?
My first thought would be the LINQ statement will return an IEnumerable by default so it probably won't be the correct type.
ppSource = (From a In application Where a.ApplicationID = ApplicationID And a.Status = 1 _
Select a).FirstOrDefault()
Might be closer to your goal...

Related

ssrs ORA_01008:NOT ALL VALIABLE BOUNDED [duplicate]

I have come across an Oracle problem for which I have so far been unable to find the cause.
The query below works in Oracle SQL developer, but when running in .NET it throws:
ORA-01008: not all variables bound
I've tried:
Changing the Oracle data type for lot_priority (Varchar2 or int32).
Changing the .NET data type for lot_priority (string or int).
One bind variable name is used twice in the query. This is not a problem in my
other queries that use the same bound variable in more than one
location, but just to be sure I tried making the second instance its
own variable with a different :name and binding it separately.
Several different ways of binding the variables (see commented code;
also others).
Moving the bindByName() call around.
Replacing each bound variable with a literal. I've had two separate variables cause the problem (:lot_pri and :lot_priprc). There were some minor changes I can't remember between the two. Changing to literals made the query work, but they do need to work with binding.
Query and code follow. Variable names have been changed to protect the innocent:
SELECT rf.myrow floworder, rf.stage, rf.prss,
rf.pin instnum, rf.prid, r_history.rt, r_history.wt
FROM
(
SELECT sub2.myrow, sub2.stage, sub2.prss, sub2.pin, sub2.prid
FROM (
SELECT sub.myrow, sub.stage, sub.prss, sub.pin,
sub.prid, MAX(sub.target_rn) OVER (ORDER BY sub.myrow) target_row
,sub.hflag
FROM (
WITH floc AS
(
SELECT flow.prss, flow.seq_num
FROM rpf#mydblink flow
WHERE flow.parent_p = :lapp
AND flow.prss IN (
SELECT r_priprc.prss
FROM r_priprc#mydblink r_priprc
WHERE priprc = :lot_priprc
)
AND rownum = 1
)
SELECT row_number() OVER (ORDER BY pp.seq_num, rpf.seq_num) myrow,
rpf.stage, rpf.prss, rpf.pin,
rpf.itype, hflag,
CASE WHEN rpf.itype = 'SpecialValue'
THEN rpf.instruction
ELSE rpf.parent_p
END prid,
CASE WHEN rpf.prss = floc.prss
AND rpf.seq_num = floc.seq_num
THEN row_number() OVER (ORDER BY pp.seq_num, rpf.seq_num)
END target_rn
FROM floc, rpf#mydblink rpf
LEFT OUTER JOIN r_priprc#mydblink pp
ON (pp.prss = rpf.prss)
WHERE pp.priprc = :lot_priprc
ORDER BY pp.seq_num, rpf.seq_num
) sub
) sub2
WHERE sub2.myrow >= sub2.target_row
AND sub2.hflag = 'true'
) rf
LEFT OUTER JOIN r_history#mydblink r_history
ON (r_history.lt = :lt
AND r_history.pri = :lot_pri
AND r_history.stage = rf.stage
AND r_history.curp = rf.prid
)
ORDER BY myrow
public void runMyQuery(string lot_priprc, string lapp, string lt, int lot_pri) {
Dictionary<int, foo> bar = new Dictionary<int, foo>();
using(var con = new OracleConnection(connStr)) {
con.Open();
using(var cmd = new OracleCommand(sql.rtd_get_flow_for_lot, con)) { // Query stored in sql.resx
try {
cmd.BindByName = true;
cmd.Prepare();
cmd.Parameters.Add(new OracleParameter("lapp", OracleDbType.Varchar2)).Value = lapp;
cmd.Parameters.Add(new OracleParameter("lot_priprc", OracleDbType.Varchar2)).Value = lot_priprc;
cmd.Parameters.Add(new OracleParameter("lt", OracleDbType.Varchar2)).Value = lt;
// Also tried OracleDbType.Varchar2 below, and tried passing lot_pri as an integer
cmd.Parameters.Add(new OracleParameter("lot_pri", OracleDbType.Int32)).Value = lot_pri.ToString();
/*********** Also tried the following, more explicit code rather than the 4 lines above: **
OracleParameter param_lapp
= cmd.Parameters.Add(new OracleParameter("lapp", OracleDbType.Varchar2));
OracleParameter param_priprc
= cmd.Parameters.Add(new OracleParameter("lot_priprc", OracleDbType.Varchar2));
OracleParameter param_lt
= cmd.Parameters.Add(new OracleParameter("lt", OracleDbType.Varchar2));
OracleParameter param_lot_pri
= cmd.Parameters.Add(new OracleParameter("lot_pri", OracleDbType.Varchar2));
param_lapp.Value = lastProcedureStackProcedureId;
param_priprc.Value = lotPrimaryProcedure;
param_lt.Value = lotType;
param_lot_pri.Value = lotPriority.ToString();
//***************************************************************/
var reader = cmd.ExecuteReader();
while(reader.Read()) {
// Get values from table (Never reached)
}
}
catch(OracleException e) {
// ORA-01008: not all variables bound
}
}
}
Why is Oracle claiming that not all variables are bound?
I know this is an old question, but it hasn't been correctly addressed, so I'm answering it for others who may run into this problem.
By default Oracle's ODP.net binds variables by position, and treats each position as a new variable.
Treating each copy as a different variable and setting it's value multiple times is a workaround and a pain, as furman87 mentioned, and could lead to bugs, if you are trying to rewrite the query and move things around.
The correct way is to set the BindByName property of OracleCommand to true as below:
var cmd = new OracleCommand(cmdtxt, conn);
cmd.BindByName = true;
You could also create a new class to encapsulate OracleCommand setting the BindByName to true on instantiation, so you don't have to set the value each time. This is discussed in this post
I found how to run the query without error, but I hesitate to call it a "solution" without really understanding the underlying cause.
This more closely resembles the beginning of my actual query:
-- Comment
-- More comment
SELECT rf.flowrow, rf.stage, rf.process,
rf.instr instnum, rf.procedure_id, rtd_history.runtime, rtd_history.waittime
FROM
(
-- Comment at beginning of subquery
-- These two comment lines are the problem
SELECT sub2.flowrow, sub2.stage, sub2.process, sub2.instr, sub2.pid
FROM ( ...
The second set of comments above, at the beginning of the subquery, were the problem. When removed, the query executes. Other comments are fine.
This is not a matter of some rogue or missing newline causing the following line to be commented, because the following line is a SELECT. A missing select would yield a different error than "not all variables bound."
I asked around and found one co-worker who has run into this -- comments causing query failures -- several times.
Does anyone know how this can be the cause? It is my understanding that the very first thing a DBMS would do with comments is see if they contain hints, and if not, remove them during parsing. How can an ordinary comment containing no unusual characters (just letters and a period) cause an error? Bizarre.
You have two references to the :lot_priprc binding variable -- while it should require you to only set the variable's value once and bind it in both places, I've had problems where this didn't work and had to treat each copy as a different variable. A pain, but it worked.
On Charles' comment problem: to make things worse, let
:p1 = 'TRIALDEV'
via a Command Parameter, then execute
select T.table_name as NAME, COALESCE(C.comments, '===') as DESCRIPTION
from all_all_tables T
Inner Join all_tab_comments C on T.owner = C.owner and T.table_name = C.table_name
where Upper(T.owner)=:p1
order by T.table_name
558 line(s) affected. Processing time: 00:00:00.6535711
and when changing the literal string from === to ---
select T.table_name as NAME, COALESCE(C.comments, '---') as DESCRIPTION
[...from...same-as-above...]
ORA-01008: not all variables bound
Both statements execute fine in SQL Developer. The shortened code:
Using con = New OracleConnection(cs)
con.Open()
Using cmd = con.CreateCommand()
cmd.CommandText = cmdText
cmd.Parameters.Add(pn, OracleDbType.NVarchar2, 250).Value = p
Dim tbl = New DataTable
Dim da = New OracleDataAdapter(cmd)
da.Fill(tbl)
Return tbl
End Using
End Using
using Oracle.ManagedDataAccess.dll Version 4.121.2.0 with the default settings in VS2015 on the .Net 4.61 platform.
So somewhere in the call chain, there might be a parser that is a bit too aggressively looking for one-line-comments started by -- in the commandText. But even if this would be true, the error message "not all variables bound" is at least misleading.
The solution in my situation was similar answer to Charles Burns; and the problem was related to SQL code comments.
I was building (or updating, rather) an already-functioning SSRS report with Oracle datasource. I added some more parameters to the report, tested it in Visual Studio, it works great, so I deployed it to the report server, and then when the report is executed the report on the server I got the error message:
"ORA-01008: not all variables bound"
I tried quite a few different things (TNSNames.ora file installed on the server, Removed single line comments, Validate dataset query mapping). What it came down to was I had to remove a comment block directly after the WHERE keyword. The error message was resolved after moving the comment block after the WHERE CLAUSE conditions. I have other comments in the code also. It was just the one after the WHERE keyword causing the error.
SQL with error: "ORA-01008: not all variables bound"...
WHERE
/*
OHH.SHIP_DATE BETWEEN TO_DATE('10/1/2018', 'MM/DD/YYYY') AND TO_DATE('10/31/2018', 'MM/DD/YYYY')
AND OHH.STATUS_CODE<>'DL'
AND OHH.BILL_COMP_CODE=100
AND OHH.MASTER_ORDER_NBR IS NULL
*/
OHH.SHIP_DATE BETWEEN :paramStartDate AND :paramEndDate
AND OHH.STATUS_CODE<>'DL'
AND OHH.BILL_COMP_CODE IN (:paramCompany)
AND LOAD.DEPART_FROM_WHSE_CODE IN (:paramWarehouse)
AND OHH.MASTER_ORDER_NBR IS NULL
AND LOAD.CLASS_CODE IN (:paramClassCode)
AND CUST.CUST_CODE || '-' || CUST.CUST_SHIPTO_CODE IN (:paramShipto)
SQL executes successfully on the report server...
WHERE
OHH.SHIP_DATE BETWEEN :paramStartDate AND :paramEndDate
AND OHH.STATUS_CODE<>'DL'
AND OHH.BILL_COMP_CODE IN (:paramCompany)
AND LOAD.DEPART_FROM_WHSE_CODE IN (:paramWarehouse)
AND OHH.MASTER_ORDER_NBR IS NULL
AND LOAD.CLASS_CODE IN (:paramClassCode)
AND CUST.CUST_CODE || '-' || CUST.CUST_SHIPTO_CODE IN (:paramShipto)
/*
OHH.SHIP_DATE BETWEEN TO_DATE('10/1/2018', 'MM/DD/YYYY') AND TO_DATE('10/31/2018', 'MM/DD/YYYY')
AND OHH.STATUS_CODE<>'DL'
AND OHH.BILL_COMP_CODE=100
AND OHH.MASTER_ORDER_NBR IS NULL
*/
Here is what the dataset parameter mapping screen looks like.
It's a bug in Managed ODP.net - 'Bug 21113901 : MANAGED ODP.NET RAISE ORA-1008 USING SINGLE QUOTED CONST + BIND VAR IN SELECT' fixed in patch 23530387 superseded by patch 24591642
Came here looking for help as got same error running a statement listed below while going through a Udemy course:
INSERT INTO departments (department_id, department_name)
values( &dpet_id, '&dname');
I'd been able to run statements with substitution variables before. Comment by Charles Burns about possibility of server reaching some threshold while recreating the variables prompted me to log out and restart the SQL Developer. The statement ran fine after logging back in.
Thought I'd share for anyone else venturing here with a limited scope issue as mine.
I'd a similar problem in a legacy application, but de "--" was string parameter.
Ex.:
Dim cmd As New OracleCommand("INSERT INTO USER (name, address, photo) VALUES ('User1', '--', :photo)", oracleConnection)
Dim fs As IO.FileStream = New IO.FileStream("c:\img.jpg", IO.FileMode.Open)
Dim br As New IO.BinaryReader(fs)
cmd.Parameters.Add(New OracleParameter("photo", OracleDbType.Blob)).Value = br.ReadBytes(fs.Length)
cmd.ExecuteNonQuery() 'here throws ORA-01008
Changing address parameter value '--' to '00' or other thing, works.

Grab data from Mysql and loop through results

I need to check a mysql table periodically and if there are any rows found, I need to loop through them and perform some actions.
My SQL string is nice and simple: "SELECT * FROM 'dbcpman_jobs'".
There could be 1 returned row, or there could be 20 returned rows.
For each returned row, I need to assign some of the data to variables...
Dim job_id As String = jobrow.Item("id")
Dim job_jobid As String = jobrow.Item("jobid")
Dim job_status As String = jobrow.Item("status")
Dim job_dbxid As String = jobrow.Item("dbxid")
Then i need to make an API call using the information that's just been split out...
Try
Dim jobapicall As New System.Net.WebClient
jobcheckresult = jobapicall.DownloadString(fulljobapicheckurl)
Catch ex As Exception
Console.WriteLine("Error 'DBX-Err-1' - Error during API call")
End Try
Can someone point me in the right direction to loop through all rows found?
My code currently checks the first item found only, which is not ideal as if that job fails, everything else gets held up.
Thanks
FOR EACH loop was the answer.
something like this...
For Each jobRow As DataRow in dtJobResults.Rows
Try
what I want to do for each returned row.
Catch Ex as exception
messagebox.show("Oh no, something went wrong!")
End Try
Next

ADODB Command failing Execute with parameterised SQL query

I have the following JScript code:
var conn = new ActiveXObject ("ADODB.Connection");
conn.Open("Driver={MySQL ODBC 5.1 Driver};Server=localhost;Database=blah_blah_blah;User=foo;Password=bar;");
var cmd = new ActiveXObject("ADODB.Command");
cmd.ActiveConnection = conn;
var strSQL = "SELECT id FROM tbl_info WHERE title LIKE :search ORDER BY id";
var search = "test";
try{
cmd.CommandText = strSQL;
var param = cmd.CreateParameter(':search', 200, 1, 100, search);
cmd.Parameters.Append(param);
var rs = cmd.Execute();
}
catch (ex) {
Application.Alert("Error retrieving id information from database.");
}
I've verified (by printing them) that the Connection object is set to be the Command's ActiveConnection, the parameter object has the correct value and the Command object has the correct SQL query as its CommandText. I also inserted an alert statement after each line in the try block to see where the error was occuring - it's fine after cmd.Parameters.Append but the exception gets thrown upon running the Execute statement.
I've tried displaying the actual exception but it's just a generic 'Object error' message.
The query executes fine and returns the correct result set when I just execute the SQL query (without the parameter) straight through the Connection object, but seems to fail when I use a parameterised query with the Command object.
As far as I can see all settings and properties of the Command and Connection objects are correct but for whatever reason it's throwing an exception.
Any help with this would be much appreciated.
With ODBC and ADO, generally speaking, a question mark ? is used as the placeholder for parameters. Parameters are bound in the order they are appended to the Parameters collection to the placeholders in the command. In your example, replace strSQL with:
var strSQL = "SELECT id FROM tbl_info WHERE title LIKE ? ORDER BY id";
You can still name the parameter that you create, but the only purpose it would serve is to be able to reference it by name later (e.g., with cmd.Parameters.Item(":search")).

How to do a simple entity copy in Linq-to-SQL?

When using a Linq-to-SQL class, how can I make a simple copy of an entity and save it?
My entity has a guid for a unique ID that gets automatically generated in the SQL Server.
I don't require a "deep clone".
I tried to use some clone methods that are out there but I couldn't figure out how to get everything serialized that needed to be serialized (got stuck on the DataContext not being serializable).
Can I just get an entity, detach it from the DataContext, null out the unique ID and InsertOnSubmit in a new DataContext? If so, how would I do this?
VB.net code preferred but not required.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
UPDATE:
Public Shared Function ReIssue(RequestID As Guid) As Guid
Dim req As Request
Dim new_req As Request
Using dc1 As New MBDataContext()
req = (From r In dc1.Requests Where r.ID = RequestID).Single()
End Using
new_req = req
new_req.ID = Guid.Empty
new_req.CreateDate = Nothing
Using dc2 As New MBDataContext()
dc2.Requests.InsertOnSubmit(new_req)
dc2.SubmitChanges()
End Using
End Function
I get an error: An attempt has been made to Attach or Add an entity that is not new, perhaps having been loaded from another DataContext. This is not supported.
on this line: dc2.Requests.InsertOnSubmit(new_req)
Nulling out the unique id and then calling InsertOnSubmit is the right way to go. Some things you have to consider though:
What is the type of the id? Is it an int? A Guid? Is it nullable? If it is nullable, make sure to set it to null, if it is an int, then to 0, or a Guid, then to Guid.Empty.
Does the type have a timestamp of some kind? If so, then you have to reset/set it to null as well, depending on the type.
Once you've done that, you can call InsertOnSubmit and then SubmitChanges and the change should take place.
Note, if you are doing this for a large number of records, you are better off writing a stored procedure which will perform the insert into the table using a select from the other table. It will be much faster that way (you won't be loading the data from the database into memory then pushing it back, inserting the records one at a time).
This method seems to have worked perfectly.
Making the final code look like this:
Public Shared Function ReIssue(RequestID As Guid) As Guid
Using dc As New MBDataContext()
Dim req As Request
req = (From r In dc.Requests Where r.ID = RequestID).Single()
Dim new_req As Request = DirectCast(Entity.Copy(req, New Request()), Request)
dc.Requests.InsertOnSubmit(new_req)
dc.SubmitChanges()
req.ActiveRequestParentID = new_req.ID
dc.SubmitChanges()
Return new_req.ID
End Using
End Function
Public NotInheritable Class Entity
Private Sub New()
End Sub
Public Shared Function Copy(source As Object, destination As Object) As Object
Dim sourceProps As System.Reflection.PropertyInfo() = source.[GetType]().GetProperties()
Dim destinationProps As System.Reflection.PropertyInfo() = destination.[GetType]().GetProperties()
For Each sourceProp As System.Reflection.PropertyInfo In sourceProps
Dim column As ColumnAttribute = TryCast(Attribute.GetCustomAttribute(sourceProp, GetType(ColumnAttribute)), ColumnAttribute)
If column IsNot Nothing AndAlso Not column.IsPrimaryKey Then
For Each destinationProp As System.Reflection.PropertyInfo In destinationProps
If sourceProp.Name = destinationProp.Name AndAlso destinationProp.CanWrite Then
destinationProp.SetValue(destination, sourceProp.GetValue(source, Nothing), Nothing)
Exit For
End If
Next
End If
Next
Return destination
End Function
End Class

why this Linq to sql function return nulls?

I am new to linq to sql
I wrote this function:
public ICollection<ICustomer> GetAll()
{
DataClasses1DataContext context = new DataClasses1DataContext();
var customers = from customer in context.Customers select customer;
return customers.ToList().Cast<ICustomer>().ToList();
}
But it always return list of null values.
The database contain 3 records "filled with data" but this function return 3 nulls.
how to fix that?
It may not be able to cast the results properly, have you made your partial Customer object implement ICustomer? If not, that is the reason.
Also you don't have to bring it to a list twice, or even once for that matter since you aren't returning a list, it might be more appropriate to change your signature to List or IEnumerable depending on your usage.
You can test whether or not the cast is succeeding by doing a simple test.
DataClasses1DataContext context = new DataClasses1DataContext();
var customers = from customer in context.Customers select customer;
int numberOfCustomers = customers.Count();
var myCustomers = customers.Cast<ICustomer>(); //you could also do .OfType<ICustomer>();
int numberOfICustomers = myCustomers.Count();
If numberOfCustomers is 3 and numberOfICustomers is 0 then you know that was the issue.
Your problem is almost certainly at the .Cast() method (confirm this by stepping through your code & ensuring that customers is populated correctly).
Does the Customer object implement the ICustomer interface? It sounds like an obvious thing to check but that would be a likely problem.