Use result of query with single result in SELECT - sqlite

I'm using Sqlite and I found out that INSERT does not return the just inserted record with the automatically created primary key.
To solve this issue I found out I can use SELECT last_insert_rowid(). This returns the value that I need.
I need this value to update a field in the record of my database.
Is there any way I could form a SELECT query that has the result of that query built in?
UPDATE events SET url='query executed' WHERE eventId = <value of above query should come here>

If SELECT last_insert_rowid() returns the value that you need then put it there as a subquery. Subquery must be in (your_subquery) brackets.

Related

Cosmos db Order by on 'computed field'

I am trying to select data based on a status which is a string. What I want is that status 'draft' comes first, so I tried this:
SELECT *
FROM c
ORDER BY c.status = "draft" ? 0:1
I get an error:
Unsupported ORDER BY clause. ORDER BY item expression could not be mapped to a document path
I checked Microsoft site and I see this:
The ORDER BY clause requires that the indexing policy include an index for the fields being sorted. The Azure Cosmos DB query runtime supports sorting against a property name and not against computed properties.
Which I guess makes what I want to do impossible with queries... How could I achieve this? Using a stored procedure?
Edit:
About stored procedure: actually, I am just thinking about this, that would mean, I need to retrieve all data before ordering, that would be bad as I take max 100 value from my database... IS there any way I can do it so I don t have to retrieve all data first? Thanks
Thanks!
ORDER BY item expression could not be mapped to a document path.
Basically, we are told we can only sort with properties of document, not derived values. c.status = "draft" ? 0:1 is derived value.
My idea:
Two parts of query sql: The first one select c.* from c where c.status ='draft',second one select c.* from c where c.status <> 'draft' order by c.status. Finally, combine them.
Or you could try to use stored procedure you mentioned in your question to process the data from the result of select * from c order by c.status. Put draft data in front of others by if-else condition.

SQLite "INSERT OR REPLACE INTO" not working

I have to write a query in sqlite to update the record if it exists or insert it if the record do not already exists. I have looked the syntax of INSERT OR REPLACE INTO from here. But in my case, when I execute the query below many times the record is duplicated. i.e If I execute the query 5 times the record is inserted 5 times.
INSERT OR REPLACE INTO NICKS
(id_nick,name_nick,date_creation)
VALUES
('nabeelarif', 'Muhammad Nabeel','2012-03-04')
Have you any idea what I am doing wrong. I am working on android platform and using 'Firefox Sqlite Manager' to test my query.
You need to have a unique index on one or a combination of those columns.
CREATE UNIQUE INDEX idx_something ON NICKS (id_nick, name_nick, date_creation);
In Android, you should use SQLiteDatabase.replace(), which does insert or update. With the Android SQLite implementation, you normally don't use raw queries represented as strings. See http://developer.android.com/reference/android/database/sqlite/SQLiteDatabase.html#replace%28java.lang.String,%20java.lang.String,%20android.content.ContentValues%29
Do you have a primary key or unique index defined for your table? I believe the attributes that make up the primary key or a unique index are used to determine if a row already exists or not.

SQLite Query to Insert a record If not exists

I want to insert a record into a sqlite table if its actually not inserted.
Let's say it has three fields pk, name, address
I want to INSERT new record with name if that name not added preveously.
Can we do with this in a single Query. Seems like its slightly different from SQL Queries sometimes.
Yes, you can do that with a single query.
INSERT ON CONFLICT IGNORE should help you: http://www.sqlite.org/lang_conflict.html
Put a unique key on the name, this will create a conflict when you try inserting a record if the name already exists.
The default is ABORT, so without the IGNORE, the statement will return an error. If you don't want that, use IGNORE.
If you can't make use of a UNIQUE INDEX in combination with INSERT INTO or INSERT OR IGNORE INTO, you could write a query like this;
INSERT INTO table (column)
SELECT value
WHERE NOT EXISTS (SELECT 1
FROM table
WHERE column = value)

asp.net InsertCommand to return latest insert ID

I'm unable to retrieve the latest inserted id from my SQL Server 2000 db using a typed dataset in asp.NET
I have created a tableadapter and I ticked the "Refresh datatable" and "Generate Insert, Update and Delete statements". This auto-generates the Fill and GetData methods, and the Insert, Update, Select and Delete statements.
I have tried every possible solution in this thread
http://forums.asp.net/t/990365.aspx
but I'm still unsuccesfull, it always returns 1(=number of affected rows).
I do not want to create a seperate insert method as the auto-generated insertCommand perfectly suits my needs.
As suggested in the thread above, I have tried to update the InsertCommand SQL syntax to add SELECT SCOPY_IDENTITY() or something similar, I have tried to add a parameter of type ReturnValue, but all I get is the number of affected rows.
Does anyone has a different take on this?
Thanks in advance!
Stijn
I decided to give up, I can't afford to waste any more time on this.
I use the Insert statement after which I do a select MAX(id) query to hget the insert ID
If anyone should have a solution, I'll be glad to read it here
Thanks
Stijn
I successfully found a way to get the incremental id after insert using my table adapter.
My approach is a little different, I'm using a Store procedure to make the insert, so my insert command has all the values but the ID, I made the sp return the ID just calling:
SET #ID=SCOPE_IDENTITY()
and then
COMMIT TRAN
and last line will be
RETURN #ID
Then I searched my table adapter parameters for InsertCommand and set the #RETURNVALUE to the column of the incremental ID of the table, so when it's executed automatically put the return value on the id field.
Hope this help
You need to tell your table's table-adapter to refresh the
data-table after update/insert operation.
This is how you can do that.
Open the properties of TableAdapter -> Default Select Query -> Advnaced options. and Check the option of Refresh the data table. Save the adapter now. Now when you call update on table-adapter, the data-table will be updated [refreshed] after the update/insert operation and will reflect the latest values from database table. if the primary-key or any coloumn is set to auto-increment, the data-table will have those latest value post recent update.
Now you can Call the update as TableAdapterObj.Update(ds.dataTable);
Read latest values from the DataTable(ds.dataTable) coloumns and assign respective values into the child table before update/insert. This will work exactly the way you want.
alt text http://ruchitsurati.net/files/tds1.png

linq to sql "Contains"

if i have a field in my table that i want to verify exists, how do i use the contains method to determine if it exists.
i would have thought the contains method just takes in a string but it seems to take in my whole linq data object
Contains is an extension method for IEnumerable that determines whether a given object is present in the enumerable. That's not what you want here.
I'm guessing that you have a LINQ query like this:
IEnumerable<string> productNames = from p in db.Products select p.ProductName;
And now you want to verify that the ProductName field actually exists to avoid run-time errors. There is actually no need to check that. Try replacing p.ProductName by a field that doesn't exist. The compiler will complain.
Of course, this assumes that the actual database schema matches the one used to generate the database class with MSLinqToSQLGenerator.
Not sure how to do it with LINQ but you could do:
SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE _NAME ='MyTable' and COLUMN _NAME='MyColumn'
then based on the count returned from the query you will know if the column exists or not.

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