Getting “java.sql.SQLException: Values not bound to statement” exception - database

I recently upgraded from sqlite-jdbc-3.7.2.jar to sqlite-jdbc-3.26.0.jar. I observed that the insert query in my code are failing with “java.sql.SQLException: Values not bound to statement” exception.
Below is the piece of code which works fine for previous version of sqlite :
String sqlStatement = "INSERT INTO table_name(id,name,type,author,size) VALUES (?,?,?,?,?)";
try
{
Connection conn = this.connect(<name>);
PreparedStatement pstmt = conn.prepareStatement(sqlStatement))
{
pstmt.setInt(1, rs.getInt(<value>));
pstmt.setString(2, rs.getString(<value>));
pstmt.setInt(3, rs.getInt(<value>));
if (somecondition)
{
pstmt.setString(4, rs.getString(<Value>));
pstmt.setInt(5, rs.getInt(<value>));
}
pstmt.executeUpdate();
}
}
catch(Exception e)
{
//handling of exception goes here
}
I have read the release notes https://www.sqlite.org/changes.html and checked that as a part of Query planner enhancements, few things were changed (The query planner examines the values of bound parameters to help determine if a partial index is usable.
).
But I am still not clear what was the enhancement and how it is affecting my code.
Also can someone guide me on how to fix the above code?
Thanks,
Ketaki

In the above program, the insert query was expecting 5 values to be populated by user.
However, if(somecondition) is not satisfied then values for 4th and 5th were not getting inserted in query. This was the issue since sqlite-jdbc-3.26.0 expects all values to be populated before executing the query. In the fix, I ensured that all values are populated even if "somecondition" is false by inserting else block.
Fix :
if (somecondition)
{
pstmt.setString(4, rs.getString(<Value>));
pstmt.setInt(5, rs.getInt(<value>));
}
else
{
pstmt.setString(4, rs.getString(<default-value>));
pstmt.setInt(5, rs.getInt(<defaul`enter code here`t-value>));
}

Related

EF Core 3.1.9 - FromRawSql using stored procedures stopped working - 'The underlying reader doesn't have as many fields as expected.'

At one point using FromSqlRaw to call stored procedures worked for me. I did not change anything in the project but now calling any stored procedure using FromSqlRaw returns
The underlying reader doesn't have as many fields as expected
I removed the model from the project and performed a BUILD. Then added the model back with no luck. I reduced the model and stored procedure to return a single column, no luck.
I tried adding Microsoft.EntityFrameworkCore.Relational as a dependency, no luck. All my unit test that use FromSqlRaw to call a stored procedure return the same error and at one time they all worked.
I have received Windows updates but nothing I know about that would have affected EF Core. I have run through all internet problem solving I can find. I am starting to think I will need to use ADO as a work around but I do not want a work around when it worked for me at one point. Something changed on my machine but I am not sure what to cause this problem.
Here is my test method in case my code is messed up. It is very straight forward not much to mess up. I tried the "var" out of desperation.
[TestMethod]
public void WorkOrderBOMGridABS()
{
List<WorkOrderBOMGridABS> baseList = new List<WorkOrderBOMGridABS>();
using (WorkOrderDataContext context = new WorkOrderDataContext())
{
var param = new SqlParameter[] {
new SqlParameter() {
ParameterName = "#WorkOrderId",
SqlDbType = System.Data.SqlDbType.Int,
Direction = System.Data.ParameterDirection.Input,
Value = 38385
}
};
baseList = context.WorkOrderBOMGridABS.FromSqlRaw("[dbo].[WorkOrderBOMGridABS] #WorkOrderId", param).ToList();
//var results = context.WorkOrderBOMGridABS.FromSqlRaw("[dbo].[WorkOrderBOMGridABS] #WorkOrderId", param).ToList();
Assert.IsNotNull(baseList);
}
}
I was using an old table to get the Unit Of Measure value that had an integer ID value. I switched it to use a new table with a VARCHAR ID value. Making this change to the stored proc and model code allowed the FromRawSql to work. Not sure why because while the integer ID value was getting an integer, either 0 or number other than 0, it was a valid value for the model. Any error message I received did not mention this UnitId field. It was a pain but I am glad it is resolved. At least until the next error I run into that much is guaranteed.

Can someone help me add a new column in Google cloud Search Index using Java

I tried adding a new column to an existing search index but it is throwing an error, the error as stated below:-
Field docname is present 0 times; expected 1
java.lang.IllegalArgumentException: Field docname is present 0 times; expected 1
I can see that the new column has been added to the search index but cannot retrieve the index.
By my observation i can see that the existing records in the index dont have the new column data and hence it is giving a this error, but the new records will be having this column values. Can anyone help me with this.
Upon having this problem myself today, I searched a bit in the documentation. It was a rather frustrating error as it didn't actually pin point where the problem was in my code.
It appears that when you use getOnlyField("something") on a Document (in this case on one of many returned from a search query), if that field does not actually exist yet in that specific document it throws the java.lang.IllegalArgumentException.
Because that can often be the case when you update an index with new columns, I'm using something like this to get around it:
public static Long getNumberField(ScoredDocument d, String name, Long defaultValue) {
try {
return d.getOnlyField(name).getNumber().longValue();
} catch (IllegalArgumentException e) {
return defaultValue;
}
}
Which is called in the search results code:
Long numberValue = SearchUtils.getNumberField(scoredDocument, "featuredOrder", -1L)
This allows me to catch that error and return a default value when it doesn't exist.
You can find the documentation here:
https://cloud.google.com/appengine/docs/java/javadoc/com/google/appengine/api/search/Document.html#getOnlyField-java.lang.String-

Sitecore search hits are null

I am running the below code
IQueryable<customSearchResultItem> query = context.GetQueryable<customSearchResultItem>().Where(CombinPredicates);
var hits = query.GetResults().Hits;
Sitecore.Diagnostics.Log.Info("search query hits:" + hits.Count(), context.Index);
foreach (var item in hits)
{
string builder = string.Empty;
try
{
string docitemid = item.Document.ItemId.ToString();
Sitecore.Diagnostics.Log.Info("document itemid:" + docitemid, item);
Item resultItem = item.Document.GetItem();
}
catch (Exception ex)
{
Sitecore.Diagnostics.Log.Info("search error going through hits:" + ex.Message, ex);
builder += item.Document.ItemId.ToString() + "\n";
continue;
}
}
the above actually returns results in the "hits" variable. However, I was getting zero results rendered out to the front end of the site. the code above is my debugging code to see what is going on.
With the hits I get back, I just loop through, nothing more.
When performing the loop and writing to logs, the below 2 lines actually return as expected, a valid Sitecore itemID
string docitemid = item.Document.ItemId.ToString();
Sitecore.Diagnostics.Log.Info("document itemid:" + docitemid, item);
However, the following line
Item resultItem = item.Document.GetItem();
returns as NULL
why would this be?
to complicate further, this code actual works in a one environment but not another, hence the reason for the debugging.
Also, the Sitecore item is present it both master and web databases and in the SOLR index
I've been having a similar problem where I was searching in the Prod (web) environment items indexed via the Stage Sitecore instance. I believe the GetItem() method uses the database, item id, language and version of the search result item, which are parsed from the _uniqueid that looks something like this:
...
"_uniqueid":"sitecore://stage/{d31b5802-c123-4690-86ff-8566dc896814}?lang=en&ver=1&ndx=my_site_index"
...
So in my case it wasn't finding the Sitecore item, because it was looking in the stage database, where as my Sitecore.Context.Database was the web one.
I know this answer is way late :-), but I hope it helps someone else who happens to run into this issue.

SQL Server (2014) Stored Procedure doesn't exist [duplicate]

I have this query and I get the error in this function:
var accounts = from account in context.Accounts
from guranteer in account.Gurantors
select new AccountsReport
{
CreditRegistryId = account.CreditRegistryId,
AccountNumber = account.AccountNo,
DateOpened = account.DateOpened,
};
return accounts.AsEnumerable()
.Select((account, index) => new AccountsReport()
{
RecordNumber = FormattedRowNumber(account, index + 1),
CreditRegistryId = account.CreditRegistryId,
DateLastUpdated = DateLastUpdated(account.CreditRegistryId, account.AccountNumber),
AccountNumber = FormattedAccountNumber(account.AccountType, account.AccountNumber)
})
.OrderBy(c=>c.FormattedRecordNumber)
.ThenByDescending(c => c.StateChangeDate);
public DateTime DateLastUpdated(long creditorRegistryId, string accountNo)
{
return (from h in context.AccountHistory
where h.CreditorRegistryId == creditorRegistryId && h.AccountNo == accountNo
select h.LastUpdated).Max();
}
Error is:
There is already an open DataReader associated with this Command which must be closed first.
Update:
stack trace added:
InvalidOperationException: There is already an open DataReader associated with this Command which must be closed first.]
System.Data.SqlClient.SqlInternalConnectionTds.ValidateConnectionForExecute(SqlCommand command) +5008639
System.Data.SqlClient.SqlConnection.ValidateConnectionForExecute(String method, SqlCommand command) +23
System.Data.SqlClient.SqlCommand.ValidateCommand(String method, Boolean async) +144
System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, DbAsyncResult result) +87
System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method) +32
System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior, String method) +141
System.Data.SqlClient.SqlCommand.ExecuteDbDataReader(CommandBehavior behavior) +12
System.Data.Common.DbCommand.ExecuteReader(CommandBehavior behavior) +10
System.Data.EntityClient.EntityCommandDefinition.ExecuteStoreCommands(EntityCommand entityCommand, CommandBehavior behavior) +443
[EntityCommandExecutionException: An error occurred while executing the command definition. See the inner exception for details.]
System.Data.EntityClient.EntityCommandDefinition.ExecuteStoreCommands(EntityCommand entityCommand, CommandBehavior behavior) +479
System.Data.Objects.Internal.ObjectQueryExecutionPlan.Execute(ObjectContext context, ObjectParameterCollection parameterValues) +683
System.Data.Objects.ObjectQuery`1.GetResults(Nullable`1 forMergeOption) +119
System.Data.Objects.ObjectQuery`1.System.Collections.Generic.IEnumerable<T>.GetEnumerator() +38
System.Linq.Enumerable.Single(IEnumerable`1 source) +114
System.Data.Objects.ELinq.ObjectQueryProvider.<GetElementFunction>b__3(IEnumerable`1 sequence) +4
System.Data.Objects.ELinq.ObjectQueryProvider.ExecuteSingle(IEnumerable`1 query, Expression queryRoot) +29
System.Data.Objects.ELinq.ObjectQueryProvider.System.Linq.IQueryProvider.Execute(Expression expression) +91
System.Data.Entity.Internal.Linq.DbQueryProvider.Execute(Expression expression) +69
System.Linq.Queryable.Max(IQueryable`1 source) +216
CreditRegistry.Repositories.CreditRegistryRepository.DateLastUpdated(Int64 creditorRegistryId, String accountNo) in D:\Freelance Work\SuperExpert\CreditRegistry\CreditRegistry\Repositories\CreditRegistryRepository.cs:1497
CreditRegistry.Repositories.CreditRegistryRepository.<AccountDetails>b__88(AccountsReport account, Int32 index) in D:\Freelance Work\SuperExpert\CreditRegistry\CreditRegistry\Repositories\CreditRegistryRepository.cs:1250
System.Linq.<SelectIterator>d__7`2.MoveNext() +198
System.Linq.Buffer`1..ctor(IEnumerable`1 source) +217
System.Linq.<GetEnumerator>d__0.MoveNext() +96
This can happen if you execute a query while iterating over the results from another query. It is not clear from your example where this happens because the example is not complete.
One thing that can cause this is lazy loading triggered when iterating over the results of some query.
This can be easily solved by allowing MARS in your connection string. Add MultipleActiveResultSets=true to the provider part of your connection string (where Data Source, Initial Catalog, etc. are specified).
You can use the ToList() method before the return statement.
var accounts =
from account in context.Accounts
from guranteer in account.Gurantors
select new AccountsReport
{
CreditRegistryId = account.CreditRegistryId,
AccountNumber = account.AccountNo,
DateOpened = account.DateOpened,
};
return accounts.AsEnumerable()
.Select((account, index) => new AccountsReport()
{
RecordNumber = FormattedRowNumber(account, index + 1),
CreditRegistryId = account.CreditRegistryId,
DateLastUpdated = DateLastUpdated(account.CreditRegistryId, account.AccountNumber),
AccountNumber = FormattedAccountNumber(account.AccountType, account.AccountNumber)
})
.OrderBy(c=>c.FormattedRecordNumber)
.ThenByDescending(c => c.StateChangeDate)
.ToList();
public DateTime DateLastUpdated(long creditorRegistryId, string accountNo)
{
var dateReported = (from h in context.AccountHistory
where h.CreditorRegistryId == creditorRegistryId && h.AccountNo == accountNo
select h.LastUpdated).Max();
return dateReported;
}
Use the syntax .ToList() to convert object read from db to list to avoid being re-read again.
Here is a working connection string for someone who needs reference.
<connectionStrings>
<add name="IdentityConnection" connectionString="Data Source=(LocalDb)\v11.0;AttachDbFilename=|DataDirectory|\IdentityDb.mdf;Integrated Security=True;MultipleActiveResultSets=true;" providerName="System.Data.SqlClient" />
</connectionStrings>
In my case, using Include() solved this error and depending on the situation can be a lot more efficient then issuing multiple queries when it can all be queried at once with a join.
IEnumerable<User> users = db.Users.Include("Projects.Tasks.Messages");
foreach (User user in users)
{
Console.WriteLine(user.Name);
foreach (Project project in user.Projects)
{
Console.WriteLine("\t"+project.Name);
foreach (Task task in project.Tasks)
{
Console.WriteLine("\t\t" + task.Subject);
foreach (Message message in task.Messages)
{
Console.WriteLine("\t\t\t" + message.Text);
}
}
}
}
I dont know whether this is duplicate answer or not. If it is I am sorry. I just want to let the needy know how I solved my issue using ToList().
In my case I got same exception for below query.
int id = adjustmentContext.InformationRequestOrderLinks.Where(
item => item.OrderNumber == irOrderLinkVO.OrderNumber
&& item.InformationRequestId == irOrderLinkVO.InformationRequestId)
.Max(item => item.Id);
I solved like below
List<Entities.InformationRequestOrderLink> links =
adjustmentContext.InformationRequestOrderLinks
.Where(item => item.OrderNumber == irOrderLinkVO.OrderNumber
&& item.InformationRequestId == irOrderLinkVO.InformationRequestId)
.ToList();
int id = 0;
if (links.Any())
{
id = links.Max(x => x.Id);
}
if (id == 0)
{
//do something here
}
It appears that you're calling DateLastUpdated from within an active query using the same EF context and DateLastUpdate issues a command to the data store itself. Entity Framework only supports one active command per context at a time.
You can refactor your above two queries into one like this:
return accounts.AsEnumerable()
.Select((account, index) => new AccountsReport()
{
RecordNumber = FormattedRowNumber(account, index + 1),
CreditRegistryId = account.CreditRegistryId,
DateLastUpdated = (
from h in context.AccountHistory
where h.CreditorRegistryId == creditorRegistryId && h.AccountNo == accountNo
select h.LastUpdated
).Max(),
AccountNumber = FormattedAccountNumber(account.AccountType, account.AccountNumber)
})
.OrderBy(c=>c.FormattedRecordNumber)
.ThenByDescending(c => c.StateChangeDate);
I also noticed you're calling functions like FormattedAccountNumber and FormattedRecordNumber in the queries. Unless these are stored procs or functions you've imported from your database into the entity data model and mapped correct, these will also throw excepts as EF will not know how to translate those functions in to statements it can send to the data store.
Also note, calling AsEnumerable doesn't force the query to execute. Until the query execution is deferred until enumerated. You can force enumeration with ToList or ToArray if you so desire.
In my case, I had opened a query from data context, like
Dim stores = DataContext.Stores _
.Where(Function(d) filter.Contains(d.code)) _
... and then subsequently queried the same...
Dim stores = DataContext.Stores _
.Where(Function(d) filter.Contains(d.code)).ToList
Adding the .ToList to the first resolved my issue. I think it makes sense to wrap this in a property like:
Public ReadOnly Property Stores As List(Of Store)
Get
If _stores Is Nothing Then
_stores = DataContext.Stores _
.Where(Function(d) Filters.Contains(d.code)).ToList
End If
Return _stores
End Get
End Property
Where _stores is a private variable, and Filters is also a readonly property that reads from AppSettings.
As a side-note...this can also happen when there is a problem with (internal) data-mapping from SQL Objects.
For instance...
I created a SQL Scalar Function that accidentally returned a VARCHAR...and then...used it to generate a column in a VIEW. The VIEW was correctly mapped in the DbContext...so Linq was calling it just fine. However, the Entity expected DateTime? and the VIEW was returning String.
Which ODDLY throws...
"There is already an open DataReader associated with this Command
which must be closed first"
It was hard to figure out...but after I corrected the return parameters...all was well
In addition to Ladislav Mrnka's answer:
If you are publishing and overriding container on Settings tab, you can set MultipleActiveResultSet to True. You can find this option by clicking Advanced... and it's going to be under Advanced group.
I solved this problem by changing
await _accountSessionDataModel.SaveChangesAsync();
to
_accountSessionDataModel.SaveChanges();
in my Repository class.
public async Task<Session> CreateSession()
{
var session = new Session();
_accountSessionDataModel.Sessions.Add(session);
await _accountSessionDataModel.SaveChangesAsync();
}
Changed it to:
public Session CreateSession()
{
var session = new Session();
_accountSessionDataModel.Sessions.Add(session);
_accountSessionDataModel.SaveChanges();
}
The problem was that I updated the Sessions in the frontend after creating a session (in code), but because SaveChangesAsync happens asynchronously, fetching the sessions caused this error because apparently the SaveChangesAsync operation was not yet ready.
For those finding this via Google;
I was getting this error because, as suggested by the error, I failed to close a SqlDataReader prior to creating another on the same SqlCommand, mistakenly assuming that it would be garbage collected when leaving the method it was created in.
I solved the issue by calling sqlDataReader.Close(); before creating the second reader.
Most likely this issue happens because of "lazy loading" feature of Entity Framework. Usually, unless explicitly required during initial fetch, all joined data (anything that stored in other database tables) is fetched only when required. In many cases that is a good thing, since it prevents from fetching unnecessary data and thus improve query performance (no joins) and saves bandwidth.
In the situation described in the question, initial fetch is performed, and during "select" phase missing lazy loading data is requested, additional queries are issued and then EF is complaining about "open DataReader".
Workaround proposed in the accepted answer will allow execution of these queries, and indeed the whole request will succeed.
However, if you will examine requests sent to the database, you will notice multiple requests - additional request for each missing (lazy loaded) data. This might be a performance killer.
A better approach is to tell to EF to preload all needed lazy loaded data during the initial query. This can be done using "Include" statement:
using System.Data.Entity;
query = query.Include(a => a.LazyLoadedProperty);
This way, all needed joins will be performed and all needed data will be returned as a single query. The issue described in the question will be solved.
The same error happened to me when I was looping and updating data on
IEnumerable<MyClass>
When I changed the looped-on collection to be List<MyClass>, and filled it by converting by .ToList(), it solved and updated without any errors.
I had the same error, when I tried to update some records within read loop.
I've tried the most voted answer MultipleActiveResultSets=true and found, that it's just workaround to get the next error 
New transaction is not allowed because there are other threads running
in the session
The best approach, that will work for huge ResultSets is to use chunks and open separate context for each chunk as described in 
SqlException from Entity Framework - New transaction is not allowed because there are other threads running in the session
Well for me it was my own bug. I was trying to run an INSERT using SqlCommand.executeReader() when I should have been using SqlCommand.ExecuteNonQuery(). It was opened and never closed, causing the error. Watch out for this oversight.
This is extracted from a real world scenario:
Code works well in a Stage environment with MultipleActiveResultSets is set in the connection string
Code published to Production environment without MultipleActiveResultSets=true
So many pages/calls work while a single one is failing
Looking closer at the call, there is an unnecessary call made to the db and needs to be removed
Set MultipleActiveResultSets=true in Production and publish cleaned up code, everything works well and, efficiently
In conclusion, without forgetting about MultipleActiveResultSets, the code might have run for a long time before discovering a redundant db call that could be very costly, and I suggest not to fully depend on setting the MultipleActiveResultSets attribute but also find out why the code needs it where it failed.
I am using web service in my tool, where those service fetch the stored procedure. while more number of client tool fetches the web service, this problem arises. I have fixed by specifying the Synchronized attribute for those function fetches the stored procedure. now it is working fine, the error never showed up in my tool.
[MethodImpl(MethodImplOptions.Synchronized)]
public static List<t> MyDBFunction(string parameter1)
{
}
This attribute allows to process one request at a time. so this solves the Issue.
In my case, I had to set the MultipleActiveResultSets to True in the connection string.
Then it appeared another error (the real one) about not being able to run 2 (SQL) commands at the same time over the same data context! (EF Core, Code first)
So the solution for me was to look for any other asynchronous command execution and turn them to synchronous, as I had just one DbContext for both commands.
I hope it helps you

Delphi : incorrect parameter message error with AdoQuery using SQL aggregate function

I use delphi XE5, I have a database with 7 tables, and my problem: I click on a button which runs this code:
dbgridappr2.Enabled:=false;
adoquery4.Parameters.Clear;
datasource6.DataSet:=adoquery4;
ADOQuery4:=TADOQuery.Create(Application);
adoquery4.Active:=False;
adoquery4.Connection:=ADOConnection1;
adoquery4.SQL.Clear;
adoquery4.SQL.Add('select SPEC.ISp AS ''Spécialité'',COUNT(APPR.NValAp) AS ''Nombre dApprentis de même Spécialité'' ');
adoquery4.SQL.Add('FROM APPR,SPEC ');
adoquery4.SQL.Add('where SPEC.CSp=APPR.CSp ');
adoquery4.SQL.Add('GROUP BY SPEC.ISp ');
adoquery4.SQL.Add('ORDER BY COUNT(APPR.NValAp) desc ');
ADOQuery4.Prepared := True;
ADOQuery4.ExecSQL;
//adoquery4.Open;
adoquery4.Active:=true;
dbgridappr2.Visible:=true;
dbgridappr2.DataSource:=datasource6;
dbgridappr2.Enabled:=true;
I have the result in a DbGrid but the message error show incorrect parameter ??
I changed the button code but I always get the same error message. I have 10 buttons that all run similar code with different AdoQuery and I have the result but I have always the same message error
The code you've posted is an absolute mess. Here's why:
You clear the adoquery4.Parameters here, and assign adoquery4 to datasource6.DataSet:
dbgridappr2.Enabled:=false;
adoquery4.Parameters.Clear;
datasource6.DataSet:=adoquery4;
You then immediately throw away the existing adoquery4 (leaking memory in the process), and replace it with a new instance of TADOQuery:
ADOQuery4:=TADOQuery.Create(Application);
You then close the newly created ADOQuery4 (which could not possibly be Active at this point), assign a connection (which would be fine), and clear the SQL (which could not possibly have any content here):
adoquery4.Active:=False;
adoquery4.Connection:=ADOConnection1;
adoquery4.SQL.Clear;
So far, about 90% of what you've done is meaningless.
Then you make the mistake of calling ADOQuery4.ExecSQL;, which is used to execute queries that return no rowset, like INSERT, DELETE, and so forth. You need to use ADOQuery4.Open or ADOQuery4.Active := True instead for a SELECT. This is the actual cause of the error you're getting; you're calling ExecSQL with an SQL statement that returns a rowset, and that's invalid.
Let's try again, and throw in a slight improvement in the SQL in the process. Ignore everything you've posted here, and start over:
ADOQuery4.DisableControls;
try
// If the query is
if ADOQuery4.Active then
ADOQuery4.Close;
ADOQuery4.Parameters.Clear;
ADOQuery4.SQL.Clear;
AdoQuery4.SQL.Add('select SPEC.ISp AS ''Spécialité'',');
AdoQuery4.SQL.Add('COUNT(APPR.NValAp) AS ''Nombre dApprentis de même Spécialité''');
AdoQuery4.SQL.Add('FROM APPR INNER JOIN SPEC');
AdoQuery4.SQL.Add('ON SPEC.CSp = APPR.CSp');
AdoQuery4.SQL.Add('GROUP BY SPEC.ISp ');
AdoQuery4.SQL.Add('ORDER BY COUNT(APPR.NValAp) desc');
ADOQuery4.Open;
finally
ADOQuery4.EnableControls;
end;
(I don't know what all of the juggling of the dbgridappr2.DataSource is about, but unless you're changing the datasource from a different query none of that is necessary. The calls to DisableControls and EnableControls stops any UI components from being updated while the new query is executed.)

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