Hi I have tried the below code
trigger CreateRecord on Account (before insert,before update) {
List<Account> CreateAcc = new List<Account>();
For(Account acc:trigger.new)
{
acc.Name='abc';
CreateAcc.add(acc);
}
insert CreateAcc;
}
but the above code is creating the following error :
Review all error messages below to correct your data.
Apex trigger CreateRecord caused an unexpected exception, contact your administrator: CreateRecord: execution of BeforeInsert caused by: System.SObjectException: DML statement cannot operate on trigger.new or trigger.old: Trigger.CreateRecord: line 9, column 1enter code here
Please help me through the code as where I am wrong.
Why don't you try to call a methods or function from a controller rather than putting your stuffs in trigger ?
On my end, I would do it like this ..
Create a utility controller with a methods that will insert a record
public class UtilityController
{
#future (callout = true)
public static void CreateRecord()
{
//Put your stuffs here...
}
}
And then in the trigger, just call that method
trigger Account_CreateNewRecord on Account (before insert,before update) {
Utility.CreateRecord();
}
Note that you can only call a method/function from another class if it has a future anotation.
I often use triggers like this to call a method on or before/after statement.
That way you're trigger was just focus on executing a method/function when it was triggered.
See Apex Developers Guide for more information about apex triggers.
Remove the update DML statement at the end. By using the "before" trigger to modify the Trigger.new objects, you don't need to explicitly perform an update, insert a DML statement. When the trigger ends, it will implicitly update or insert the data as you have modified the values.
trigger CreateRecord on Account (before insert,before update) {
List<Account> CreateAcc = new List<Account>();
For(Account acc:trigger.new)
{
acc.Name='abc';
CreateAcc.add(acc);
}
//insert CreateAcc; removed this line.
}
Related
I am trying my hands on spring-data-r2dbc. I am try this on Postgresql. I have tried spring-data-mongodb-reactive before. I couldn't help but to compare both.
I see that Query Derivation is not yet supported. But I was wondering if there is an equivalent for #Tailable. This way I would be notified of the database changes in real time. Ca anyone share any code samples with respect to this.
I understand that the underlying database should support this. I believe Postgresql does support this kinda thing using Logical Decoding(Correct me if I am wrong here).
Is there a #Tailable equivalent in spring-data-r2dbc ?
I was on the same issue not sure if you found a solution or not but I was able to accomplish something similar by doing the following. First, I added trigger to my table
CREATE TRIGGER trigger_name
AFTER INSERT OR DELETE OR UPDATE
ON table_name
FOR EACH ROW
EXECUTE PROCEDURE trigger_function_name;
This will set a trigger on the table whenever a row, is updated, deleted, or inserted. Then it will call the trigger function I have set up which looked something like this:
CREATE FUNCTION trigger_function_name
RETURNS trigger
LANGUAGE 'plpgsql'
COST 100
VOLATILE NOT LEAKPROOF
AS
$BODY$
DECLARE
payload JSON;
BEGIN
payload = row_to_json(NEW);
PERFORM pg_notify('notification_name', payload::text);
RETURN NULL;
END;
$BODY$;
This will allow me to 'listen' to the any of these updates from my spring boot project and it will send the entire row as a payload.
Next, in my spring boot project I configured a connection to my db.
#Configuration
#EnableR2dbcRepositories("com.(point to wherever repository is)")
public class R2DBCConfig extends AbstractR2dbcConfiguration {
#Override
#Bean
public ConnectionFactory connectionFactory() {
return new PostgresqlConnectionFactory(PostgresqlConnectionConfiguration.builder()
.host("host")
.database("db")
.port(port)
.username("username")
.password("password")
.schema("schema")
.connectTimeout(Duration.ofMinutes(2))
.build());
}
}
With that I Autowire (dependency injection) it into the constructor in my service class and cast it to a r2dbc PostgressqlConnection class like so:
this.postgresqlConnection = Mono.from(connectionFactory.create()).cast(PostgresqlConnection.class).block();
Now we want to 'listen' to our table and get the notified when perform some update to our table. To do that we set up an initialization method that is performed after dependency injection by using the #PostContruct annotation
#PostConstruct
private void postConstruct() {
postgresqlConnection.createStatement("LISTEN notification_name").execute()
.flatMap(PostgresqlResult::getRowsUpdated).subscribe();
}
Notice that we listen to whatever name we put inside the pg_notify method. Also we want to set up a method to close the the connection when the bean is about to be tossed away, like so:
#PreDestroy
private void preDestroy() {
postgresqlConnection.close().subscribe();
}
Now I simply create a method that returns a Flux of whatever is currently in my table, and I also merge it with my notifications, as I said before the notifications come in as a json, so I had to deserialize it and I decided to use ObjectMapper. So, it will look something like this:
private Flux<YourClass> getUpdatedRows() {
return postgresqlConnection.getNotifications().map(notification -> {
try {
//deserialize json
return objectMapper.readValue(notification.getParameter(), YourClass.class);
} catch (IOException e) {
//handle exception
}
});
}
public Flux<YourClass> getDocuments() {
return documentRepository.findAll().share().concatWith(getUpdatedRows());
}
Hope this helps.
Cheers!
When we pass our DbContext an object whose values have not changed, and try to perform an Update we get a 500 internal server error.
A user may open a dialog box to edit a record, change a value, change it back and then send the record to the database. Also we provide a Backup and Restore function and when the records are restored, some of them will not have changed since the backup was performed.
I was under the impression that a PUT would delete and re-create the record so I didn't feel there would be a problem.
For example, having checked that the Activity exists my ActivityController is as follows:
var activityEntityFromRepo = _activityRepository.GetActivity(id);
// Map(source object (Dto), destination object (Entity))
_mapper.Map(activityForUpdateDto, activityEntityFromRepo);
_activityRepository.UpdateActivity(activityEntityFromRepo);
// Save the updated Activity entity, added to the DbContext, to the SQL database.
if (await _activityRepository.SaveChangesAsync())
{
var activityFromRepo = _activityRepository.GetActivity(id);
if (activityFromRepo == null)
{
return NotFound("Updated Activity could not be found");
}
var activity = _mapper.Map<ActivityDto>(activityFromRepo);
return Ok(activity);
}
else
{
// The save failed.
var message = $"Could not update Activity {id} in the database.";
_logger.LogWarning(message);
throw new Exception(message);
};
My ActivityRepository is as follows:
public void UpdateActivity(Activity activity)
{
_context.Activities.Update(activity);
}
If any of the fields have changed then we don't get the error. Do I have to check every record for equality before the PUT? It seems unnecessary.
Perhaps I have missed something obvious. Any suggestions very welcome.
There is a lot of code missing here.
In your code you call your SaveChangesAsync (not the EF SaveChangesAsync).
Probably (but there is not the code to be sure) your SaveChangesAsync is something that returns false if there is an exception (and is not a good pattern because you "loose" the exception info) or if DbSet.SaveChangesAsync returns 0.
I think (but there is a lot of missing code) that this is your case. If you don't make any changes, SaveChangesAsync returns 0.
EDIT
The System.Exception is raised by your code (last line). EF never throws System.Exception.
I am looking to replace the rollups in my Salesforce rollup helper with apex versions, and run those instead. I am trying to transform the following into Apex code. Please let me know if you have any ideas.
This is a very straight forward use case for Apex. You need to create a Trigger on the child object that will do the math and update the parent object.
Best Practices dictate that the Trigger should actually call a method in a class, but here is an abbreviated version of the solution:
trigger myTrigger on Collateral__c (after insert, after update){
Map<Id, Deal__c> dealMap = new Map<Id, Deal__c>();
for ( Collateral__c c : Trigger.new ){
dealMap.put( c.Deal__c, new Deal__c( Id=c.Deal__c, Total_Lendable_Collateral__c=0) );
}
for ( AggregateResult ar : [
SELECT Deal__c parentId, SUM(Lendable_Value__c) s
FROM Collateral__c
WHERE Deal__c IN :dealMap.keySet()
]){
Id i = (Id)ar.get('parentId');
dealMap.put( i, new Deal__c(Id=i,Total_Lendable_Collateral__c=(Decimal)ar.get('s')));
}
update dealMap.values();
}
I need to implement a cassandra trigger in java that will take a different action for INSERT vs UPDATE operations.
I've seen how it is possible to identify a DELETE operation in the question Cassandra sample trigger to get the deleted row and column values but I can't see any methods in the ColumnFamily object that would allow allow the code to differentiate between INSERT vs UPDATE, is there a way to achieve this?
There isn't conceptually any difference between INSERT and UPDATE. Indeed an INSERT and an UPDATE are just mutation. Cassandra gives them different name so that people coming from the relational DB have familiar concepts
As #doanduyhai mentioned and according to Casssandra sources only INSERT operation updates row timestamp (LivenessInfo).
For other operations this timestamp is not updated and equals Long.MIN_VALUE.
Custom Trigger which checks for INSERT operation
public class CustomTrigger implements ITrigger {
#Override
public Collection<Mutation> augment(Partition partition) {
checkQueryType(partition));
return Collections.emptyList();
}
private void checkQueryType(Partition partition) {
UnfilteredRowIterator it = partition.unfilteredIterator();
while (it.hasNext()) {
Unfiltered unfiltered = it.next();
Row row = (Row) unfiltered;
if (isInsert(row)) {
// Implement insert related logic
}
}
}
private boolean isInsert(Row row) {
return row.primaryKeyLivenessInfo().timestamp() != Long.MIN_VALUE;
}
}
I'm trying to create my database (code first) and I want to add some data in it when it's created.
public class InitializerWithData : CreateDatabaseIfNotExists<DatabaseContext>
{
protected override void Seed(DatabaseContext ctx)
{
GroupType gt = new GroupType() { Name = "RNC" };
//save
ctx.GroupType.Add(gt);
ctx.SaveChanges();
}
}
public DatabaseContext()
{
Database.SetInitializer<DatabaseContext>(new InitializerWithData());
Database.CreateIfNotExists();
}
As you can see I wrote my custom initializer but the code inside it is never fired though the database does get created.
So how do I solve this?
When you call Database.CreateIfNotExists(), it doesn't trigger the InitializeDatabase of the initializer. Basically it has separated implementation than the initializer.
If you want the Seed method to be fired. You need to execute a code that causes EF to send a query to the database.
First remove this line.
Database.CreateIfNotExists();
Then just execute a query, the least you could have is something like.
using(var db = new DatabaseContext())
{
db.Set<GroupType>().Any();
}
This code will create the database if it doesn't exist and execute the Seed method.