We have tried it using an orm mapper tool, but it opens en closes the connection 750 times. Then we tried to construct a bulk insert, but that goes even slower...
The help file that came with Dynamic Linq in the CSharpSamples.zip does not show any examples of using contains or like.
Are there any simple workarounds for doing this? i.e where (col like @col) doesn't work.
In MySQL you can insert multiple rows like this:
INSERT INTO 'tablename' ('column1', 'column2') VALUES
('data1', 'data2'),
('data1', 'data2'),
('data1', 'data2'),
('data1', 'data2');
However, I am getting an error when I try to do something like this. Is it possible to insert multiple rows at a time in an SQLite database? What is the syntax to do that?
I like an idea of document oriented databases like CouchDB. I am looking for simple analog.
My requirements is just:
persistance storage for schema less data;
some simple in-proc quering;
good to have transactions and versioning;
ruby API;
map/reduce is aslo good to have;
should work on shared hosting
What I do not need is REST/HTTP interfaces (I will use it in-proc). Also I do not need all scalability stuff.
I have some Oracle tables that represent a parent-child relationship. They look something like this:
create table Parent (
parent_id varchar2(20) not null primary key
);
create table Child (
child_id number not null primary key,
parent_id varchar2(20) not null,
constraint fk_parent_id
foreign key (parent_id)
references Parent (parent_id)
);
This is a live database and its schema was designed long ago under the assumption that the parent_id field would be static and unchanging for a given record. Now the rules have changed and we really would like to change the value of parent_id for some records.
For example, I have these records:
Parent:
parent_id
---------
ABC123
Child:
child_id parent_id
-------- ---------
1 ABC123
2 ABC123
And I want to modify ABC123 in these records in both tables to something else.
It's my understanding that one cannot write an Oracle update statement that will update both parent and child tables simultaneously, and given the FK constraint, I'm not sure how best to update my database. I am currently disabling the fk_parent_id constraint, updating each table independently, and then enabling the constraint.
Is there a better, single-step way to update this content?
i have a table "request" with 4 columns namely:
1.recId :long primary key
2.interactionId:long
3.requestedBy:boolean
4.requestedType:boolean
and data is as follows:
VALUES
(185,455699,0,5),
(186,455746,0,1),
(187,455746,1,1),
(188,455752,0,1),
(189,455753,0,1),
(190,455753,1,1),
(191,455754,1,1)
i want a query to fetch all the rows where interactionId is same and having requestedBy both 1 and 0 values and requestType=1;
regards,
Nihar
I'm working for a university project, and I have the following question:
I have 2 tables in a Oracle DB... I need to select those rows from table1, which are not included in table2... But the main problem is that I need to exclude that rows from table2 wich was selected once... For example:
Table1 Table2 ResultTable
id | Number | Letter id | Number | Letter id | Number | Letter
_____________________ _____________________ _____________________
1 4 S 1 6 G 2 2 P
2 2 P 2 8 B 3 5 B
3 5 B 3 4 S 4 4 S
4 4 S 4 1 A 6 2 P
5 1 A 5 1 H
6 2 P 6 2 X
So, how you see it, if one row from Table1 has a "twin" in Table2, they both are excluded.
Hope I was explicit enough. Sorry for my bad English. Thanks.
I'm trying construct a PostgreSQL query that does the following but so far my efforts have been in vain.
Problem:
There are two tables: A and B. I'd like to select all columns from table A (having columns: id, name, description) and substitute the "A.name" column with the value of the column "B.title" from table B (having columns: id, table_A_id title, langcode) where B.table_A_id is 5 and B.langcode is "nl" (if there are any rows).
I've tried using a CASE and COALESCE() but failed due to my inexperience with both concepts.
Thanks in advance.
Does it make a difference if you do count(*) vs count(column-name) as in these two examples?
I have a tendency to always write count(*) because it seems to fit better in my mind with the notion of it being an aggregate function, if that makes sense.
But I'm not sure if it's technically best as I tend to see example code written without the * more often than not.
count(*):
select customerid, count(*), sum(price)
from items_ordered
group by customerid
having count(*) > 1;
vs. count(column-name):
SELECT customerid, count(customerid), sum(price)
FROM items_ordered
GROUP BY customerid
HAVING count(customerid) > 1;
OpenAL is such a huge thing, and the documentation doesn't tell what values are acceptable for properties. That's really bad.
I'm using the document: "OpenAL_Programmers_Guide.pdf"
Whenever I look up a property I'm left in the dark what value might be ok. For example, take AL_PITCH. What value?
Maybe someone wrote a better one? Or is there something like a wiki place with more details?
I have a PHP application using an Oracle XE database.
Whenever I add a date the hours minutes, and seconds seem to get left out.
Is there some special format, or type I should use to be able to store this? I have tried using to_date, and specifying the format I am using.
Many thanks for any suggestions from this confused MySql dveloper.
I've been asked to resolve an issue with a .Net/SqlServerCe application. Specifically, after repeated inserts against the db, performance becomes increasingly degraded. In one instance at ~200 rows, in another at ~1000 rows. In the latter case the code being used looks like this:
Dim cm1 As System.Data.SqlServerCe.SqlCeCommand = cn1.CreateCommand
cm1.CommandText = "INSERT INTO Table1 Values(?,?,?,?,?,?,?,?,?,?,?,?,?)"
For j = 0 To ds.Tables(0).Rows.Count - 1 'this is 3110
For i = 0 To 12
cm1.Parameters(tbl(i, 0)).Value = Vals(j,i) 'values taken from a different db
Next
cm1.ExecuteNonQuery()
Next
The specifics aren't super important (like what 'tbl' is, etc) but rather whether or not this code should be expected to handle this number of inserts, or if the crawl I'm witnessing is to be expected.
The whole question is pretty much in the title. For each row of the table I'd like to select the maximum of a subset of columns.
For example, from this table
name m1 m2 m3 m4
A 1 2 3 4
B 6 3 4 5
C 1 5 2 1
the result would be
name max
A 4
B 6
C 5
The query must be compatible oracle 8i.
Thanks.
I am new to the concept of Pipeline Functions. I have some questions regarding
From Database point of view:
What actually is Pipeline function ?
What is the advantage of using Pipeline Function ?
What challenges are solved using Pipeline Function ?
Are the any optimization advantages of using Pipeline Function ?
Thanks.
I have these rows in a table
ID Name Price Delivery
== ==== ===== ========
1 apple 1 1
2 apple 3 2
3 apple 6 3
4 apple 9 4
5 orange 4 6
6 orange 5 7
I want to have the price at the third delivery (Delivery=3) or the last price if there's no third delivery.
It would give me this :
ID Name Price Delivery
== ==== ===== ========
3 apple 6 3
6 orange 5 7
I don't necessary want a full solution but an idea of what to look for would be greatly appreciated.
Do you ever use a separate table for "generating" artificial primary keys for DB (and why)? What I mean is to have a table with two columns, table name and current ID - with which you could get new "ID" for some table by simply locking the row with that table name, getting the current value of the key, increment it by one, and unlock the row. Why would you prefer this over standard integer identity column?
P.S. The "idea" is from Fowlers Patterns of Enterprise Application Architecture, btw...
I have run into a bottleneck when trying to update one of my tables.
The player table has, among other things, id, skill, school, weight.
What I am trying to do is:
SELECT id, skill
FROM player
WHERE player.school = (current school of 4500)
AND player.weight = (current weight of 14)
to find the highest skill of all players returned from the query
UPDATE player
SET starter = 'TRUE'
WHERE id = (highest skill)
move to next weight and repeat
when all weights have been completed
move to next school and start over
all schools completed, done
I have this code implemented and it works, but I have approximately 4500 schools totaling 172000 players and the way I have it now, it would take probably a half hour or more to complete (did not wait it out), which is way too slow.
How to speed this up? Short of reducing the scale of the system, I am willing to do anything that gets the intended result.
Thanks!
*the weights are the standard folk style wrestling weights
ie, 103, 113, 120, 126, 132, 138, 145, 152, 160, 170, 182, 195, 220, 285 pounds
I'm would like to use Scala to persist data to a relational database, so what I am looking for are examples of CRUD operations using Scala.
I would like to code on a lower level of abstraction than an ORM like Hibernate/Toplink (read:JDBC), but between us, I would like to see examples of all types.
Thanks folks.
Bit of an odd one for you:
I've got two connections to a database, on one I've opened a _RecordsetPtr with a pessimistic lock. I can no longer send an UPDATE command on the other connection. I can send a SELECT command on the second connection and data is returned. If I use a read only lock then there are no problems however when I use a pessimistic lock on the second connection as well I can check the State == adStateOpen but the program hangs when I test the BOF property!
If I don't test the BOF property and try to call moveNext on the second connection the software hangs
If I do neither of these I am able to access the data via the second connection but trying to access the data from the first connection causes the software to hang.
Any one seen anything similar as I'm a bit stuck?
EDIT : it wasn't hanging, someone had put a 30 minute timeout on the connection and I wasn't waiting that long while testing...
I create a new table of employee now I want to edit one of the column name in that table. I can edit but while saving a pop up window asks to save some text file. How may I resolve this? Is it possible to edit without creating a new table?
The text file is
/*
Friday, August 22, 20144:32:53 PM
User:
Server: MIDHUN\SQLEXPRESS
Database: LinQ
Application:
*/
employee
I've got a Python CGI script that pulls data from a GPS service; I'd like this information to be updated on the webpage about once every 10s (the max allowed by the GPS service's TOS). But there could be, say, 100 users viewing the webpage at once, all calling the script.
I think the users' scripts need to grab data from a buffer page that itself only upates once every ten seconds. How can I make this buffer page auto-update if there's no one directly viewing the content (and not accessing the CGI)? Are there better ways to accomplish this?
I have got a simple MySQL table and primary index (id) is not numbered one by one (1, 31, 35, 100 etc.). I want them to be numbered like (1, 2, 3, 4). Please tell me how to do it. I would also like to point that I am aware of possible consequences of the operation, but I just want to tidy up the table.
I am looking for an overview of data synchronization techniques available on the iPhone platform. We need the ability to be able to sync a subset of content from a server to a local database residing on the iPhone.
On other projects I have worked on, the data synchronization was handled by the database. Is that available in SQLite? If not, any suggestions on techniques? Rolling our own would not be my first choice.
Thanks in advance.