I have an issues running around my mind regarding default for 'id' field in my postgresql database. Here is the syntax:-
nextval('unsub_keyword_id_seq'::regclass)
However I'm not really understands even after read the documentations & I would like to set the value only for integer(digit only). I try to alter the column by change regclass to other OIDs but each time it will return errors.
Really appreciate if can get this solved very soon.
Update:
It just come to my idea on the data type for the column after I try & error with the code that will produce the id for the column.
Is integer(postgresql in this case) have it's own default length or not?
If I need to to insert long id, should I set the column length?
Kindly advise.
sorry if my questions quite confusing. your comments may help me to improve it.
From the comments:
I need to insert an id with length of 50 with consist of 2 alphabets & the rest is numeric. the problems occur as the data type is in integer & the data inserting in unsuccessful. is it possible to insert my desired data by retain the data type to integer?
If I understand this correctly, you probably need to format a string, e.g.
format('%s%s', 'XX', nextval('some_sequence_name'))
Related
I have a table with a JSON column and some of the values in it are numbers but I want all the values to be text. For example, I have {"budget": 500}, but I want it to be {"budget":"500"}. I have tried using the JSONB_SET function but even after postgres returns N rows updated, when I go to retrieve the records, they are still numbers. I was hoping that somebody may have encountered this issue. Here's what I've tried that isn't working.
UPDATE my_table
SET data = JSONB_SET(data, '{budget}', data->'budget'::text)
WHERE data ? 'budget' = true;
Since this is a very large table, hardcoding values is not feasible. If anybody knows why this isn't working or if there is something that does work, please let me know, thank you!
You can enforce converting a JSONB number to text with the function quote_ident():
UPDATE my_table
SET data = jsonb_set(data, '{budget}', quote_ident(data->>'budget')::jsonb)
WHERE data ? 'budget'
-- you can add this condition to avoid updating non-numbers
-- AND jsonb_typeof(data->'budget') = 'number'
Note that data->'budget'::text does nothing as the cast refers to 'budget', not a JSON object and the expression is equivalent to data->'budget'.
I am working on a database that (hopefully) will end up using a primary key with both numbers and letters in the values to track lots of agricultural product. Due to the way in which the weighing of product takes place at more than one facility, I have no other option but to maintain the same base number but use letters in addition to this base number to denote split portions of each lot of product. The problem is, after I create record number 99, the number 100 suddenly floats up and underneath 10. This makes it difficult to maintain consistency and forces me to replace this alphanumeric lot ID with a strictly numeric value in order to keep it sorted (which I use "autonumber" as the data type). Either way, I need the alphanumeric lot ID, and so having 2 ID's for the same lot can be confusing for anyone inputting values into the form. Is there a way around this that I am just not seeing?
If you're using query as a data source then you may try to sort it by string converted to number, something like
SELECT id, field1, field2, ..
ORDER BY CLng(YourAlphaNumericField)
Edit: you may also try Val function instead of CLng - it should not fail on non-numeric input
Why not properly format your key before saving ? e.g: "0000099". You will avoid a costly conversion later.
Alternatively, you could use 2 fields as the composite PK. One with the Number (as Long) and one with the Location (as String).
I have a CLOB(2000000) field in a db2 (v10) database, and I would like to run a simple UPDATE query on it to replace each occurances of "foo" to "baaz".
Since the contents of the field is more then 32k, I get the following error:
"{some char data from field}" is too long.. SQLCODE=-433, SQLSTATE=22001
How can I replace the values?
UPDATE:
The query was the following (changed UPDATE into SELECT for easier testing):
SELECT REPLACE(my_clob_column, 'foo', 'baaz') FROM my_table WHERE id = 10726
UPDATE 2
As mustaccio pointed out, REPLACE does not work on CLOB fields (or at least not without doing a cast to VARCHAR on the data entered - which in my case is not possible since the size of the data is more than 32k) - the question is about finding an alternative way to acchive the REPLACE functionallity for CLOB fields.
Thanks,
krisy
Finally, since I have found no way to this by an SQL query, I ended up exporting the table, editing its lob content in Notepad++, and importing the table back again.
Not sure if this applies to your case: There are 2 different REPLACE functions offered by DB2, SYSIBM.REPLACE and SYSFUN.REPLACE. The version of REPLACE in SYSFUN accepts CLOBs and supports values up to 1 MByte. In case your values are longer than you would need to write your own (SQL-based?) function.
BTW: You can check function resolution by executing "values(current path)"
This is probably a super simple question, but I'm struggling to come up with the right keywords to find it on Google.
I have a Postgres table that has among its contents a column of type text named content_type. That stores what type of entry is stored in that row.
There are only about 5 different types, and I decided I want to change one of them to display as something else in my application (I had been directly displaying these).
It struck me that it's funny that my view is being dictated by my database model, and I decided I would convert the types being stored in my database as strings into integers, and enumerate the possible types in my application with constants that convert them into their display names. That way, if I ever got the urge to change any category names again, I could just change it with one alteration of a constant. I also have the hunch that storing integers might be somewhat more efficient than storing text in the database.
First, a quick threshold question of, is this a good idea? Any feedback or anything I missed?
Second, and my main question, what's the Postgres command I could enter to make an alteration like this? I'm thinking I could start by renaming the old content_type column to old_content_type and then creating a new integer column content_type. However, what command would look at a row's old_content_type and fill in the new content_type column based off of that?
If you're finding that you need to change the display values, then yes, it's probably a good idea not to store them in a database. Integers are also more efficient to store and search, but I really wouldn't worry about it unless you've got millions of rows.
You just need to run an update to populate your new column:
update table_name set content_type = (case when old_content_type = 'a' then 1
when old_content_type = 'b' then 2 else 3 end);
If you're on Postgres 8.4 then using an enum type instead of a plain integer might be a good idea.
Ideally you'd have these fields referring to a table containing the definitions of type. This should be via a foreign key constraint. This way you know that your database is clean and has no invalid values (i.e. referential integrity).
There are many ways to handle this:
Having a table for each field that can contain a number of values (i.e. like an enum) is the most obvious - but it breaks down when you have a table that requires many attributes.
You can use the Entity-attribute-value model, but beware that this is too easy to abuse and cause problems when things grow.
You can use, or refer to my implementation solution PET (Parameter Enumeration Tables). This is a half way house between between 1 & 2.
I have a problem, I would like to build logging system which will be using timeuuid type as a column name which will allow me ask for it later.
Since for range queries order by time I need to use timeuuid type I would like to ask you how can I specify range queries for timeuuid column names if timeuuid is every time unique and I don't realy know the column name because of that I just know the time when it has been stored ?
please help
OK all works, it turned out that column names are not required but you can't use null you need to use empty string instead