Sorry im new to Oracle store procedure, I have a cursor declared to query table from another schema as following:
CURSOR A IS select * from <schema>.Employee where conditions
My schema's name is actually being kept in a table, say, Table A, so I need to query from Table A and pass it in the cursor as variable.
Does anyone know how I could do that?
Related
I want to save the results of my sqlite query in a new sqlite file. in other words, I want to have a new sqlite database with the data which resulted from my query on my previous data set.
All I have found on the internet was how to export the query results to csv or sql. but I want my new data set to be sqlite.
Also, is there any way to save the query results on the same data set (like what we do in excel)? Thank you!
You can ATTACH another database file to an existing connection and create or insert data into a table in that other database.
Something like:
ATTACH DATABASE 'other.db' AS other;
CREATE TABLE other.foo AS SELECT * FROM main.foo; -- create and populate a table
INSERT INTO other.bar SELECT * FROM main.foo; -- insert into an existing table
DETACH other;
I've seen enough answers to know you can't easily check for columns in SQLITE before adding. I'm trying to make a lazy person's node in Node-Red where you pass a message to SQLITE which is the query. Adding a table if it does not exist is easy.
msg.topic='create table IF NOT EXISTS fred (id PRIMARY KEY);'; node.send(msg);
it occurred to me that adding a table which had the names of the fields would be easy - and if the field name is not in the table.... then add the field. BUT you can't add multiple fields at once - so I can't do this...
msg.topic='create table IF NOT EXISTS fred (id PRIMARY KEY, myfields TEXT);'; node.send(msg);
The problem with THAT is that I can't add this in later, there's no way to check before adding a field it the table exists!
This is what I WANT
msg.topic='create table IF NOT EXISTS fred (id PRIMARY KEY, myfields TEXT);'; node.send(msg);
msg.topic='if not (select address from myfields) alter table fred add column address text';
I just cannot think of any way to do this - any ideas anyone (the idea is that the node-red node would input a table, field and value and if the table didn't exist it would be created, if the field didn't exist it would be created, all before trying to add in the value).
You won't be able to make the ALTER TABLE conditional in the SQL itself. You'll need to handle that from your calling script.
Alternately, simply attempt to add the column to the table and accept failure as an outcome. Assuming the table exists, the only failure reason you could encounter is that the column already exists.
If you'd like to do something more graceful, you can check if the column exists in advance, then conditionally run the SQL from your calling application.
I want create table from another table with constraint?
I used this query "create table destination as select * from source;" fro table creation.
But its copy only the column name in table without column constraint.
There is a special table named sqlite_master, holding the full CREATE TABLE statement for each table (it's modified as appropriate during ALTER TABLE).
I would make my application retrieve that CREATE TABLE statement:
SELECT sql FROM sqlite_master WHERE type='table' AND name='source';
Then I would replace the table name right after CREATE TABLE tokens, and execute the result as a new sqlite query.
I don't think that it's possible to do in sqlite's pure SQL without extensions.
I have a object that contains data from a DB. The object has a ID, which in the DB is auto increment field. When creating an object i dont know his ID, until i insert a new record to the DB. Then i want to get back the auto generated value of ID field.
I tried to do so by adding a Output parameter, but SQLite.NET throws a NotSupportedException when i try to set the Direction to ParameterDirection.Output.
What can i do? The other fields except ID are not unique.
A other option is to auto increment manually, in the program, but it seems to be a bit complicated to implement.
Thanks a lot.
SELECT last_insert_rowid();
This will get the last inserted ROWID. If the table has a column of type INTEGER PRIMARY KEY then that column is another alias for the rowid.
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)