I am fetching rows of record from my sqlite table for blackberry application.But certain fields contain a null and i get a run time error of No stack trace at those field.How i can i continue fetching data irrespective of their null fields.
This is how my table looks
Date Bill Receipt
12/5/2012 50
16/4/2012 40 20
1/6/2012 50 30
It gives me error for that third element of first row.
This is my code used for retrieving values
grid.insert(new LabelField(r.getString(k))
continuously going through 3 for loops-one for row,one for column and one for each column of database table.
If anyone aware on a solution to this,please share.Thanks.
Use Row.getObject() instead of Row.getString(). It will return 'null' for null values without throwing an exception. If non-null, you can then do a type check, or just cast to String if you know it will always be of type string.
Related
I have a SQLite database that contains a table called "players". I can see in DB Browser that the data in the table is correct however when attempting to retrieve the data it seems to be returning a totally different value than what's in the database.
Value in DB: 76561198113034550
Value returned : 152768822
I'm getting the value with the following
qryPlayers.Close;
qryPlayers.SQL.Text := 'SELECT * FROM players';
qryPlayers.Open;
playerID := qryPlayers.FieldByName('steamid').Value; // .AsString returns the same value
Whats causing this and how can I fix it?
I just checked, what value the 4 lower bytes of 76561198113034550 have... And tadaaa, it is 152768822! So the upper 4 bytes are simply truncated.
Declare playerID as Int64, not Integer or Cardinal since those types only have 4 bytes in memory.
And for retrieving the value from the DB use qryPlayers.FieldByName('steamid').AsLargeInt.
I am trying to fill a datatable in vb using SQLiteDataAdapter from a SQLITE database. There are 3 fields in the table that contain dates and they appear as either recent dates or "1899-12-30" . The Fill command generates a "String was not recognized as a valid DateTime." error. I cannot find a date entry that does not look valid, except "1899-12-30", is this a valid date?
Any other thoughts would be appreciated.
Brad
The short answer is 'yes'. I built a table with the three possible ways of storing dates, thus:
CREATE TABLE `JustDate` ( `Date_1` INTEGER, `Date_2` TEXT, `Date_3` REAL )
Then I populated each of those fields in one record with the value you suspect.
And then I did a trial query against the fields to see if sqlite would treat them as proper dates.
My application ingests data from a 3rd party REST API which is backed by DynamoDB. The results are paginated and thus I page forward by passing the last evaluated key to each subsequent request.
My question is does the last evaluated key have a shelf life? Does it ever expire?
Let's say I query the REST API and then decide to stop. If I save the last evaluated key, can pick up exactly where I left off 30 days later? Would that last evaluated key still work and return the correct next page based on where I left off previously?
You shouldn't think of the last evaluated key like a "placeholder" or a "bookmark" in a result set from which to resume paused iteration.
You should think of it more like a "start from" place marker. An example might help. Let's say you have a table with a hash key userId and a range key timestamp. The range key timestamp will provide an ordering for your result set. Say your table looked like this:
user ID | Timestamp
1 | 123
1 | 124
1 | 125
1 | 126
In this order, when you query the table for all of the records for userId 1, you'll get the records back in the order they're listed above, or ascending order by timestamp. If you wanted them back in descending order, you'd use Dyanmo DB's scanIndexForward flag to indicate to order them "newest to oldest" or in descending order by timestamp.
Now, suppose there were a lot more than 4 items in the table and it would take multiple queries to return all of the records with a userId of one. Well, you wouldn't want to have to keep getting pages and pages back, so you can tell Dynamo DB where to start by giving it the last evaluated key. Say the last result for the previous query was the record with userId = 1 and timestamp = 124. You tell Dynamo in your query that that was the last record you got, and it will start your next result set with the record that has userId = 1 and timestamp = 125.
So the last evaluated key isn't something that "expires," it's a way for you to communicate to Dynamo which records you want it to return based on records that you've already processed, displayed to the user, etc.
How can I get MS Access 2010 to include data in a query if 1 field has missing data.
IE: I have a sn column in tblPropertydevices and a sn column in tblBrentwoodID that is imported from another source. If there is a typo in the imported data sn column, the entire report is not printed.
I would like for the report to print all reports & ignore the missing data in the one column. I have tried "<>"" Or is null" in the criteria for that column wth no results.
The query pulls data from several tables and prints test reports based on date tested and tech#. That is the only 2 fields that absolutely have to match.
Found the solution.
All you have to do is click on the relationship line in the query and select the 2nd radio button to include all records from the firs table.
Too easy
Toby
This is odd because I'm not inserting data, I'm pulling data with a query.
I'm trying to run
SELECT DISTINCT description FROM products;
Which outputs the error "The field is too small to accept the amount of data you attempted to add.".
However, running the following doesn't produce the error:
SELECT description FROM products;
So I'm confused as to what the issue would be.
I'm using OleDbDataReader and taking data out of an mdb database file.
This might be related to: http://support.microsoft.com/kb/896950/us
This problem occurs because when you
set the UniqueValues query property to
Yes, a DISTINCT keyword is added to
the resulting SQL statement. The
DISTINCT keyword directs Access to
perform a comparison between records.
When Access performs a comparison
between two Memo fields, Access treats
the fields as Text fields that have a
255-character limit. Sometimes Memo
field data that is larger than 255
characters will generate the error
message that is mentioned in the
"Symptoms" section. Sometimes only 255
characters are returned from the Memo
field.
Workaround:
To work around this problem, modify
the original query by removing the
Memo field. Then, create a second
query that is based on both the table
and the original query. This new query
uses all the fields from the original
query, and this new query uses the
Memo field from the table. When you
run the second query, the first query
runs. Then, this data is used to run
the second query. This behavior
returns the Memo field data based on
the returned data of the first query.