I want to know if there's any way to recover the deleted or updated records updated accidentally in an Informix DB?
The table structure is like this:
ID NAME CODE
1 john yy7
2 Rany uu6
3 Mike hh7
The data has been updated to:
ID NAME CODE
1 XX yy7
2 XX uu6
3 XX hh7
Related
Right now I've got a Main table in which I am uploading data. Because the Main table has many different duplicates, I Append various data out of the Main table into other tables such as, username, phone number, and locations in order to keep things optimized. Once I have everything stripped down from the Main table, I then append what's left into a final optimized Main table. Before this happens though, I run a select query joining all the stripped tables with the original Main table in order to connect the IDs from each table, with the correct data. For example:
Original Main Table
--Name---------Number------Due Date-------Location-------Charges Monthly-----Charges Total--
John Smith 111-1111 4/3 Chicago 234.56 500.23
Todd Jones 222-2222 4/3 New York 174.34 323.56
John Smith 111-1111 4/3 Chicago 274.56 670.23
Bill James 333-3333 4/3 Orlando 100.00 100.00
This gets split into 3 tables (name, number, location) and then there is a date table with all the dates for the year:
Name Table Number Table Location Table Due Date Table
--ID---Name------ -ID--Number--------- ---ID---Location---- --Date---
1 John Smith 1 111-1111 1 Chicago 4/1
2 Todd Jones 2 222-2222 2 New York 4/2
3 Bill James 3 333-3333 3 Orlando 4/3
Before The Original table gets stripped, I run a select query that grabs the ID from the 3 new tables, and joins them based on the connection they have with the original Main table.
Select Output
--Name ID----Number ID---Location ID---Due Date--
1 1 1 4/3
2 2 2 4/3
1 1 1 4/3
3 3 3 4/3
My issue comes when I need to introduce a new table that isn't able to be tied into the Original Main Table. I have an inventory table that, much like the original Main table, has duplicates and needs to be optimized. I do this by creating a secondary table that takes all the duplicated devices out and put them in their own table, and then strips the username and number out and puts them into their tables. I would like to add the IDs from this new device table into the select output that I have above. Resulting in:
Select Output
--Name ID----Number ID---Location ID---Due Date--Device ID---
1 1 1 4/3 1
2 2 2 4/3 1
1 1 1 4/3 2
3 3 3 4/3 1
Unlike the previous tables, the device table has no relationship to the originalMain Table, which is what is causing me so much headache. I can't seem to find a way to make this happen...is there anyway to accomplish this?
Any two tables can be joined. A table represents an application relationship. In some versions (not the original) of Entity-Relationship Modelling (notice that the "R" in E-R stands for "(application) relationship"!) a foreign key is sometimes called a "relationship". You do not need other tables or FKs to join any two tables.
Explain, in terms of its column names and the values for those names, exactly when a row should turn up in the result. Maybe you want:
SELECT *
FROM the stripped-and-ID'd version of the Original AS o
JOIN the stripped-and-ID'd version of the Device AS d
USING NameID, NumberID, LocationID and DueDate
Ie
SELECT *
FROM the stripped-and-ID'd version of the Original AS o
JOIN the stripped-and-ID'd version of the Device AS d
ON o.NameID=d.NameId AND o.NumberID=d.NumberID
AND o.LocationID=d.LocationID AND o.DueDateID=d.DueDate.
Suppose p(a,...) is some statement parameterized by a,... .
If o holds the rows where o(NameID,NumberID,LocationID,DueDate) and d holds the rows where d(NameID,NumberID,LocationID,DueDate,DeviceID) then the above holds the rows where o(NameID, NumberID, LocationID, DueDate) AND d(NameID,NumberID,LocationID,DueDate,DeviceID). But you really have not explained what rows you want.
The only way to "join" tables that have no relation is by unioning them together:
select attribute1, attribute2, ... , attributeN
from table1
where <predicate>
union // or union all
select attribute1, attribute2, ... , attributeN
from table2
where <predicate>
the where clauses are obviously optional
EDIT
optionally you could join the tables together by stating ON true which will act like a cross product
I'm creating a simple directory listing page where you can specify what kind of thing you want to list in the directory e.g. a person or a company.
Each user has an UserTypeID and there is a dbo.UserType lookup table. The dbo.UserType lookup table is like this:
UserTypeID | UserTypeParentID | Name
1 NULL Person
2 NULL Company
3 2 IT
4 3 Accounting Software
In the dbo.Users table we have records like this:
UserID | UserTypeID | Name
1 1 Jenny Smith
2 1 Malcolm Brown
3 2 Wall Mart
4 3 Microsoft
5 4 Sage
My SQL (so far) is very simple: (excuse the pseudo-code style)
DECLARE #UserTypeID int
SELECT
*
FROM
dbo.Users u
INNER JOIN
dbo.UserType ut
WHERE
ut.UserTypeID = #UserTypeID
The problem is here is that when people want to search for companies they will enter in '2' as the UserTypeID. But both Microsoft and Sage won't show up because their UserTypeIDs are 3 and 4 respectively. But its the final UserTypeParentID which tells me that they're both Companies.
How could I rewrite the SQL to ask it to return to return records where the UserTypeID = #UserTypeID or where its final UserTypeParentID is also equal to #UserTypeID. Or am I going about this the wrong way?
Schema Change
I would suggest you to break it down this schema a little bit more, to make your queries and life simpler, with this current schema you will end up writing a recursive query every time you want to get simplest data from your Users table, and trust me you dont want to do this to yourself.
I would break down this schema of these tables as follow:
dbo.Users
UserID | UserName
1 | Jenny
2 | Microsoft
3 | Sage
dbo.UserTypes_Type
TypeID | TypeName
1 | Person
2 | IT
3 | Compnay
4 | Accounting Software
dbo.UserTypes
UserID | TypeID
1 | 1
2 | 2
2 | 3
3 | 2
3 | 3
3 | 4
You say that you are "creating" this - excellent because you have the opportunity to reconsider your whole approach.
Dealing with hierarchical data in a relational database is problematic because it is not designed for it - the model you choose to represent it will have a huge impact on the performance and ease of construction of your queries.
You have opted for an Adjacently List model which is great for inserts (and deletes) but a bugger for selects because the query has to effectively reconstruct the hierarchy path. By the way an Adjacency List is the model almost everyone goes for on their first attempt.
Everything is a trade off so you should decide what queries will be most common - selects (and updates) or inserts (and deletes). See this question for starters. Also, since SQL Server 2008, there is a native HeirachyID datatype (see this) which may be of assistance.
Of course, you could store your data in an XML file (in SQL Server or not) which is designed for hierarchical data.
I wonder which has better performance in this case. First of all, I want to show to the user his medical information. I have two tables
user
-----
id_user | type_blood | number | ...
1 O 123
2 A+ 442
user_allergies
-----------
id_user | name
1 name1
1 name2
I want to return:
JSON {id_user=1, type_blood=0, allergies=(name1,name2)}
So, Its better do a JOIN for user and user_allergies and iterate, or maybe two SELECT?
But if then I have another table like user_allergies, that the result can be:
user_another_table
-----------
id_user | name
1 namet1
1 namet2
1 namet3
JSON {id_user=1, type_blood=0, allergies=(name1,name2), table=(namet1,namet2,namet3)}
It's better three SELECT or a JOIN, but then I have to iterate on the results and I can't imagine a esay way. A JOIN can give me a result like:
id_user | type_blood | allergy_name | another_table_name
1 O name1 namet1
1 O name1 namet2
1 O name1 namet3
1 O name2 namet1
1 O name2 namet2
1 O name2 namet3
Is there any way to extract:
id_user | type_blood | allergy_name | another_table_name
1 O name1 namet1
1 O name2 namet2
1 O namet3
Thanks community, I'm newbie in SQL
Depending on the data - there is no way to get the 2nd set of results you've shown, if the 1st set of results shows the values. The 2nd one is throwing data away - in this case allergy 'name2' for another_table_name 'namet3'. This is why you get many rows back with repeated data.
You can use the group by clause to restrict this in some cases, but again - it won't let you throw away data like that.
You could try using the COALESCE clause, if your DB supports it.
If not, I think you're going to have to construct your JSON in some business logic, in which case its fine to read the data in a 3-way join. You order by the user id and either create or append the row data to the JSON document depending if a user record is present or not (if you order by user id, you only need to keep track of when the user id value changes).
Alternatively, you can read a list of users and single-item data in one query, and then ht the DB again for the repeating data.
I created a table out of a CSV file which is produced by an external software.
Amongst the other fields, this table contains one field called "CustomID".
Each row on this table must be linked to a customer using the content of that field.
Every customer may have one or more set of customIDs at their own discretion, as long as each sequence starts with the same prefix.
So for example:
Customer 1 may use "cust1_n" and "cstm01_n" (where n is a number)
Customer 2 may use "customer2_n"
ImportedRows
PKID CustomID Description
---- --------------- --------------------------
1 cust1_001 Something
2 cust1_002 ...
3 cstm01_000001 ...
4 customer2_00001 ...
5 cstm01_000232 ...
..
Now I have created 2 support tables as follows:
Customers
PKID Name
---- --------------------
1 Customer 1
2 Customer 2
and
CustomIDs
PKID FKCustomerID SearchPattern
---- ------------ -------------
1 1 cust1_*
2 1 cstm01_*
3 2 customer2_*
What I need to achieve is the retrieval of all rows for a given customer using all the LIKE conditions found on the CustomIDs tables for that customer.
I have failed miserably so far.
Any clues, please?
Thanks in advance.
Silver.
To use LIKE you must replace the * with % in the pattern. Different dbms use different functions for string manipulation. Let's assume there is a REPLACE function available:
SELECT ir.*
FROM ImportedRows ir
JOIN CustomIDs c ON ir.CustomID LIKE REPLACE(c.SearchPattern, '*', '%')
WHERE c.FKCustomerID = 1;
I am using Oracle 11g. The rankings are not static. They change based on how a user ranks the items.
I would like to keep a live record of rankings 1-10 using both a Rank (1-10) column and the ID of the object. So that a user can continually rate a collection of objects and the rankings stay correct. I've found decent a decent workaround below but there are problems with gaps:
// REMOVAL
UPDATE ... SET orderingID=NULL WHERE orderingID=removedID
UPDATE ... SET orderingID=orderingID-1 WHERE orderingID > removedID
// INSERTION
UPDATE ... SET orderingID=orderingID+1 WHERE orderingID > insertionID
UPDATE ... SET orderID=insertionID WHERE ID=addedID
If I have a table as such:
RANK | OBJECT
1 | AA
6 | BB
Using the above alogithm I ran into problems with gaps in the number. For example, if I insert a 2 i get:
RANK | OBJECT
1 | AA
2 | DD
7 | BB
The 6 becomes a 7 when it should stay at 6. Is there a way to do this in SQL using update statements or a store procedure ?