I am trying to pull data starting from today, to last 10 transactions i.e. I am getting the first 10 transactions and then I want to apply scroll up / down to move to previous 10 / next 10 transactions.
SELECT * FROM table_transaction LIMIT 10
I tried the above query this gives a LIMIT of 10 starting from the top (Today's to last 10 transaction details)
How do I implement the above logic?
Can somebody help me fix this?
if you want get 10 starting from the top
SELECT * FROM table_transaction LIMIT 0,10
and if you want next 10 item:
SELECT * FROM table_transaction LIMIT 1,10
You can use the ROWID column of the sqlite tables. This column is automatically managed by the sqlite.
Sqlite Documantation
Use OrderBy Clause for geting last n number of transaction -
SELECT * FROM table_transaction LIMIT 10 ORDER BY COLUMN_NAME DESC
above query returns last 10 inserted transaction.
For Scrolling you have to create logic create an integer variable say 'last_order_id' and assign it to max order id.
In your query pass last order id and every time you execute query update 'last_order_id'.
So your updated query will be -
SELECT * FROM table_transaction LIMIT 10 ORDER BY COLUMN_NAME DESC INNER JOIN table_transaction.order_id<last_order_id;
hope it will help you.
Related
I have a database from which I would like to take the last 3 records. For example if I had the lines 1,2,3,4,5,6, ... 10,11,12,13,14, I would like 12,13,14 no matter the order (12,13,14 for me is equal to 14,13,12).
I tried to follow another question at this link Android SQLite Query - Getting latest 10 records
but what I get is just showing the first 3 rows of the database.
This is my query
String query2 ="select * from (select * from USERS order by ID ASC limit 3)";
In any case you can sort by rowid descending and get 3 rows:
select * from USERS order by rowid desc limit 3
If you want to sort by a specific column:
select * from USERS order by columnname desc limit 3
This question already has answers here:
How to get Top 5 records in SqLite?
(8 answers)
Closed 8 years ago.
My Android application has an activity to present data from SQLite database. The db table might contain huge number of rows. For performance reasons, I want to load 20 rows from db at a time, and when user scrolls down listview to the end, read next 20 rows.
So I want to use SQL statement like this:
select * from mytable where id > N and count = 20;
I just wonder if SQLite supports this kind of "count=20" feature to read at maximum 20 rows for the query. If it is supported, what is exact syntax?
Yes, it does. It is called LIMIT:
SELECT *
FROM mytable
WHERE id > N
LIMIT 20
You can also use optional OFFSET clause to start at certain row:
SELECT *
FROM mytable
WHERE id > N
LIMIT 20
OFFSET 100
You can use LIMIT and OFFSET to specify a set of rows to return.
However:
This is risky if other threads may be updating the database, particularly if your query will use ORDER BY.
Use tools like Traceview to really determine how long things take, and use that to determine the number of rows to fetch. 20 seems seriously annoying.
If your "table might contain huge number of rows", you should be focused on a search interface, not expecting people to browse linearly through some list that is long enough to warrant this sort of batching.
I want to get the latest 5 records in my table, so far i tried this but, it did not work out very well. So, what is the cleanest and efficient way to get last 5 records in the table ?
"select * from (select * from People order by Date DESC limit 5) order by Date ASC;"
Your query works just fine.
To make it efficient, ensure that there is an index on the Date column; then SQLite will just read the last five entries from the index and the table and does not need to scan the entire table.
If this table has an autoincrementing ID column, and if "latest" means the insertion order, then you can use that ID for sorting; this will be as efficient as your original query with an index on Date:
SELECT * FROM (SELECT * FROM People
ORDER BY _id DESC
LIMIT 5)
ORDER BY Date ASC
I am developing an android application in which i have a database table and i want to display only last three rows from the database how can i achieve it ?
As a SQL table has no inherent order, you have to specify something you want to order by, like a date or id and limit the result to 3.
SELECT * FROM yourTable ORDER BY date DESC LIMIT 3
I have a database that stores the rank of an Item.
The rank is an absolute value that will be correct if all the items are taken into account.
If I only need a subset say four of this items it will give me something like:
Rank RowId in the whole Table
---------------
4 114
8 71
70 16
83 7
I now need an int specifying the rank only in the subset where the max rank is the number of items in the subset in my example 1,2,3,4.
Is there a way to achieve this in my sqlite query? I only need one of the ranks in my Activity. I thought of ordering the results of the query by rank and then somehow get the position of item I want to rank at that moment. But how would I achieve this with sqlite?
I tried to create a temporary table and insert the subset into it like this:
CREATE TABLE rank(ID);
INSERT INTO position SELECT ID from items WHERE ITEM_ID = 3 ORDER BY POSITION;
SELECT RowID from rank WHERE ID = 9;
DROP TABLE rank;
This is working in SQLite Manager and will return the correct number. But if I do this in Android in fails saying that there is no table rank while compiling query
07-07 13:35:46.150: ERROR/AndroidRuntime(2047): Caused by: android.database.sqlite.SQLiteException: no such table: rank: , while compiling: SELECT RowID from rank WHERE ID = 9
EDIT: have to agree with #Matt the only way I've been able to do this is to use the temp table approach.
For what it's worth here's what it looks like...
create temp table if not exists <temptable>(Id integer primary key, rank);
insert into temptable(rank) select <column> from <table>;
select * from temptable;
EDIT: Actually that returns the ID associated with the row which isn't sequential so you won't always get 1,2,3,4... I'll have to think of something else. Sorry.
Not sure if I've understood your question. You basically want this?
Id Value
---------------
1 4
2 8
3 70
4 83
So you want to add a pseudo-column as the id no matter what your subset contains?
If that's correct then this should do it...
SELECT RowId, <other columns>.... FROM <table> WHERE <where>
Apologies if I've misunderstood.
You could output your query (ordered by rank) into a temporary table with an auto increment ID.
If you need to read only one row from a subquery you can always execute a limit on it, by providing the offset of how many records to be skipped first, and how much to be returned
so if you want to get 25th row you tell to skip 24, and return 1
select * from (SELECT * FROM table order by rank) limit 24,1