This seems like a simple request. But my query in not working and I'm finding conflicting answers on the internet. Is it possible to have UPDATE and INSERT using a Stored Procedure joining 2 tables in MySql?
I have an Asp.net Webforms website. It has 2 tables Individual and Address. Individual table contains data on an individual, i.e. Phone Number, Fax, Email ect.
The address table has all the address information for an individual. They each table has a column of Individual ID which auto increments. (Note: the individualID in Address table is not a primary key, but individualID in the individual table is a primary key.
Anyway, I have a FormView in Asp.net that with a SELECT statement that joins those 2 tables and display the data fine. But updating new information to both tables keeps failing.
My most recent error is : Duplicate entry '0' for key 'PRIMARY'
Is there a way to write an UPDATE statement that joins 2 Tables?? This has to exist right?
It is possible to update multiple tables with a single query -
UPDATE table1
INNER JOIN table2
ON table1.id = table2.table1_id
SET table1.col1 = 'some value', table2.col1 = 'Another value'
WHERE <some where clause>;
Related
Similar to this question and this solution for PostgreSQL (in particular "INSERT missing FK rows at the same time"):
Suppose I am making an address book with a "Groups" table and a "Contact" table. When I create a new Contact, I may want to place them into a Group at the same time. So I could do:
INSERT INTO Contact VALUES (
"Bob",
(SELECT group_id FROM Groups WHERE name = "Friends")
)
But what if the "Friends" Group doesn't exist yet? Can we insert this new Group efficiently?
The obvious thing is to do a SELECT to test if the Group exists already; if not do an INSERT. Then do an INSERT into Contacts with the sub-SELECT above.
Or I can constrain Group.name to be UNIQUE, do an INSERT OR IGNORE, then INSERT into Contacts with the sub-SELECT.
I can also keep my own cache of which Groups exist, but that seems like I'm duplicating functionality of the database in the first place.
My guess is that there is no way to do this in one query, since INSERT does not return anything and cannot be used in a subquery. Is that intuition correct? What is the best practice here?
My guess is that there is no way to do this in one query, since INSERT
does not return anything and cannot be used in a subquery. Is that
intuition correct?
You could use a Trigger and a little modification of the tables and then you could do it with a single query.
For example consider the folowing
Purely for convenience of producing the demo:-
DROP TRIGGER IF EXISTS add_group_if_not_exists;
DROP TABLE IF EXISTS contact;
DROP TABLE IF EXISTS groups;
One-time setup SQL :-
CREATE TABLE IF NOT EXISTS groups (id INTEGER PRIMARY KEY, group_name TEXT UNIQUE);
INSERT INTO groups VALUES(-1,'NOTASSIGNED');
CREATE TABLE IF NOT EXISTS contact (id INTEGER PRIMARY KEY, contact TEXT, group_to_use TEXT, group_reference TEXT DEFAULT -1 REFERENCES groups(id));
CREATE TRIGGER IF NOT EXISTS add_group_if_not_exists
AFTER INSERT ON contact
BEGIN
INSERT OR IGNORE INTO groups (group_name) VALUES(new.group_to_use);
UPDATE contact SET group_reference = (SELECT id FROM groups WHERE group_name = new.group_to_use), group_to_use = NULL WHERE id = new.id;
END;
SQL that would be used on an ongoing basis :-
INSERT INTO contact (contact,group_to_use) VALUES
('Fred','Friends'),
('Mary','Family'),
('Ivan','Enemies'),
('Sue','Work colleagues'),
('Arthur','Fellow Rulers'),
('Amy','Work colleagues'),
('Henry','Fellow Rulers'),
('Canute','Fellow Ruler')
;
The number of values and the actual values would vary.
SQL Just for demonstration of the result
SELECT * FROM groups;
SELECT contact,group_name FROM contact JOIN groups ON group_reference = groups.id;
Results
This results in :-
1) The groups (noting that the group "NOTASSIGNED", is intrinsic to the working of the above and hence added initially) :-
have to be careful regard mistakes like (Fellow Ruler instead of Fellow Rulers)
-1 used because it would not be a normal value automatically generated.
2) The contacts with the respective group :-
Efficient insertion
That could likely be debated from here to eternity so I leave it for the fence sitters/destroyers to decide :). However, some considerations:-
It works and appears to do what is wanted.
It's a little wasteful due to the additional wasted column.
It tries to minimise the waste by changing the column to an empty string (NULL may be even more efficient, but for some can be confusing)
There will obviously be an overhead BUT in comparison to the alternatives probably negligible (perhaps important if you were extracting every Facebook user) but if it's user input driven likely irrelevant.
What is the best practice here?
Fences again. :)
Note Hopefully obvious, but the DROP statements are purely for convenience and that all other SQL up until the INSERT is run once
to setup the tables and triggers in preparation for the single INSERT
that adds a group if necessary.
I am using crystal reports XI. I am working with a SQL database that was created before I got here, and I can't make changes to the tables or link structure. There are 4 tables in the database that I need for this report.
Table 1 - Companies || Fields: CompanyIDPK, CompanyName, YearActiveIDFK
Table 2 - ActiveYears || Fields: YearActiveIDPK, YearNameIDFK
Table 3 - YearNames || Fields: YearNameIDPK, YearName
Table 4 - CompanyOrders || Fields: OrderIDPK, CompanyIDFK, YearNameIDFK, OrderNumber, OrderCost
I want to create a report that is grouped by Year and by Company. I want each company to show the number of orders within each year, including showing 0 if there were no orders that year.
I can get the report to show all the companies that were in a given year, but as soon as I try to start showing a count, it only shows companies that had at least one order.
Thanks for any help!!!
My guess is that this is happening because Crystal only adds tables to your SQL query after you've added them to the designer. This happens even if you have linked your tables in the database expert.
I'm assuming you have the default join type of INNER JOIN. What's probably happening is as soon as you add your Count Summary on one of the fields in CompanyOrders, Crystal is adding it to your SQL Query.
The reason this causes a problem is because an inner join only returns records if the linked fields are in both tables. If companies haven't placed an order in the last year, they won't have any records in the CompanyOrders table. This means your SQL Query won't return any records for those companies, because those companies need to be in both tables for records to be returned.
The solution for this is to change the join type from INNER JOIN to LEFT OUTER JOIN. This can be accomplished by going into the Database Expert (Menu > Database > Database Expert), clicking the Links tab, double clicking the line that goes from your Companies to your CompanyOrders table, and selecting the Left Outer Join Radio button.
Now all of the Companies will show up, but since some don't have records in the CompanyOrders table, the count for the orders will be 0.
Let me know if this was your problem.
ZMcK
You didn't say that you couldn't create database objects, so if it is possible I would create a view or stored procedure in the SQL Server database to return the data you require in the format you want and take Crystal Reports out of the equation in terms of linking tables.
I am running a website using SQL Server 2008 and ASP.NET 4.0. I am trying to trace an issue down that my stored procedure is creating duplicate entries for the same date. Originally I thought this may be a couple post issue but the duplicates are recording the same date down to the milliseconds. One of the duplicates is at :'2013-04-26 15:48:28.323' All of the data is exactly the same except for the id.
#check_date is an input into the stored procedure which gives us the particular date we are looking at (entries are maid daily)
#formHeaderId is grabbed earlier in the stored procedure, getting the header ID as this is a detail table with a 1 to many relationship with the header.
The #getdate() entry is where I found the duplicate entries, there are entries with the exact getdate() values for different rows.
This doesn't occur with each entry either, it is randomly occurring in the application.
select #formHeaderId=stage2_checklist_header_id
from stage2_checklist_header
where environmental_forms_id=#envFormId
and checklist_monthyear=#inspected_month
order by start_date desc
if #formHeaderId = 0 begin
insert into stage2_checklist_header(
environmental_forms_id
,start_date
,checklist_monthyear
,st2h_load_date )
values( #envFormId
,#check_date
,#inspected_month
,getdate())
set #formHeaderId = scope_identity()
print 'inserted new header record ' + cast(#formHeaderId as varchar(50))
end
IF (NOT EXISTS(
SELECT *
FROM stage2_checklist_detail
WHERE stage2_checklist_header_id = #formHeaderId
AND check_date = #check_date
))
INSERT INTO stage2_checklist_detail
(stage2_checklist_header_id, check_date, st2_chk_det_load_date,
inspected_by)
VALUES
(#formHeaderId, #check_date, GETDATE(), #inspected_by)
SET #form_detail_id = SCOPE_IDENTITY()
PRINT 'inserted detail record ' + CAST(#form_detail_id AS VARCHAR(50))
Here is a similar case where the developer was able to track the duplicate entries to simultaneous calls from different spids (which sidestepped the EXISTS check). After experimenting with isolation levels and transactions - and trying to avoid deadlocks - it sounds like the solution in that case was to use sp_getapplock and sp_releaseapplock.
In the NOT EXISTS check, you are looking for records that have both the same ID and the same date. So, if the combination of ID AND date does not exist in the table, the row will be inserted.
In your description of the problem you state "All of the data is exactly the same except for the id". The ID being different will always cause an INSERT based on the logic you are using to check for existence.
I have a table that needs to merge from same table in another database.
Condition is one of the column in composite primary key is generated by sequence and may differ in another database.
How can we sync remaining columns in this situation?
Ex.
DB1:
Table: SRE_SERVICE_OPTION
Columns:(OPTION_SET_ID, OPTION_NAME, OPTION_VALUE, VALUE_ORDER)
DB2:
Table: SRE_SERVICE_OPTION
Columns:(OPTION_SET_ID, OPTION_NAME, OPTION_VALUE, VALUE_ORDER)
Primary key:
OPTION_SET_ID, OPTION_NAME, VALUE_ORDER
How should I write merge statement?
You've made the classic error in a distributed database. Simply put, by using two separate sequences you have an inconsistent primary key across the tables. You will only be able to use MERGE if your tables are both separately unique on OPTION_NAME, OPTION_VALUE and VALUE_ORDER.
Your only other hope is that your tables do not contain any duplicated information between them. If so you can simply insert from one into the other.
Otherwise, you are, I'm afraid out of luck. I would re-design your database so that it's impossible to send duplicated information into two different tables with separate, inconsistent, surrogate keys.
Is there a one-statement select-and-update (or update-and-select) method in SQLite?
A trigger can invoke select, but that doesn't allow update to be used in an expression:
CREATE TABLE id ( a integer );
CREATE TRIGGER idTrig AFTER UPDATE ON id BEGIN SELECT old.a FROM id; END;
INSERT INTO id VALUES ( 100 );
INSERT INTO test VALUES ( (UPDATE id SET a=a+1) ); -- syntax error
(Is a triggered select only accessible via the C API?)
I generate object IDs for several databases from a single ID database (with a single row for the next available ID). I'd like to select-and-update on the ID db in one statement, so that concurrent db connections which attach the ID db won't have trouble with this (where two connections could insert before either updates):
INSERT INTO tab VALUES ( (SELECT uuid||oid AS oid FROM id.tab), ... );
UPDATE id.tab SET oid = oid+1;
I'll start with the prerequisite nag: why not use GUIDs? They don't require central authority and are thus more efficient and easier to work with.
If you really need a central ID store, you can make the ID an autoincrement and fetch it with SELECT last_insert_rowid(). If you have to generate your own IDs, then make the ID column a primary key, so you can generate the ID, INSERT it, and retry if the INSERT fails.
This discussion presents two possible solutions:
http://www.mail-archive.com/sqlite-users#sqlite.org/msg10705.html