I am using bean property ro wmapper to match my DB column names with variables to do select * from table to data class. But if the column name is something like this which has number after underscore:
WEEK_7DAYS, I have property name in my POJO as week7days. but that is not matching and no values ar set to week&days. I tried week7Days too. That is also not working. how to match it. Please help.
Thanks,
Sreenivas
Specifically, this scenario deals with underscores in front of numbers..
Fail condition:
Example: WEEK_7DAYS -> getWeek7Days()
Strangely, spring attempts to ADD IN the underscores of camelCased method signatures to derive the key in the result set.
In your case, Spring would guess that getWeek7Days() would translate to something like WEEK7_DAYS, and never in any case would it try to place an underscore in front of a number.
If you want your method to be handled properly, you have to retain any underscores that are proceeded by a number.
your successful method name would be getWeek_7days()
Use aliases in your query:
select t.id, t.WEEK_7DAYS as week7days from mytable t
I suggest you alter the table field name as WEEK_7_DAYS or alter the property name in the POJO as week7days. Be careful of the lower case and the upper case.
Related
I have a table called profile, and I want to order them by which ones are the most filled out. Each of the columns is either a JSONB column or a TEXT column. I don't need this to a great degree of certainty, so typically I've ordered as follow:
SELECT * FROM profile ORDER BY LENGTH(CONCAT(profile.*)) DESC;
However, this is slow, and so I want to create an index. However, this does not work:
CREATE INDEX index_name ON profile (LENGTH(CONCAT(*))
Nor does
CREATE INDEX index_name ON profile (LENGTH(CONCAT(CAST(* AS TEXT))))
Can't say I'm surprised. What is the right way to declare this index?
To measure the size of the row in text representation you can just cast the whole row to text, which is much faster than concatenating individual columns:
SELECT length(profile::text) FROM profile;
But there are 3 (or 4) issues with this expression in an index:
The syntax shorthand profile::text is not accepted in CREATE INDEX, you need to add extra parentheses or default to the standard syntax cast(profile AS text)
Still the same problem that #jjanes already discussed: only IMMUTABLE functions are allowed in index expressions and casting a row type to text does not pass this requirement. You could build a fake IMMUTABLE wrapper function, like Jeff outlined.
There is an inherent ambiguity (that applies to Jeff's answer as well!): if you have a column name that's the same as the table name (which is a common case) you cannot reference the row type in CREATE INDEX since the identifier always resolves to the column name first.
Minor difference to your original: This adds column separators, row decorators and possibly escape characters to the text representation. Shouldn't matter much to your use case.
However, I would suggest a more radical alternative as crude indicator for the size of a row: pg_column_size(). Even shorter and faster and avoids issues 1, 3 and 4:
SELECT pg_column_size(profile) FROM profile;
Issue 2 remains, though: pg_column_size() is also only STABLE. You can create a simple and cheap SQL wrapper function:
CREATE OR REPLACE FUNCTION pg_column_size(profile)
RETURNS int LANGUAGE sql IMMUTABLE AS
'SELECT pg_catalog.pg_column_size($1)';
and then proceed like #jjanes outlined. More details:
Does PostgreSQL support "accent insensitive" collations?
Note that I created the function with the row type profile as parameter. Postgres allows function overloading, which is why we can use the same function name. Now, when we feed the matching row type to pg_column_size() our custom function matches more closely according to function type resolution rules and is picked instead of the polymorphic system function. Alternatively, use a separate name and possibly make the function polymorphic as well ...
Related:
Is there a way to disable function overloading in Postgres
You can declare a function which is falsely marked "immutable" and build an index on that.
CREATE OR REPLACE FUNCTION len_immut(record)
RETURNS int
LANGUAGE plperl
IMMUTABLE
AS $function$
## This function lies about its immutability.
## Use it with care. It is useful for indexing
## entire table rows.
return length(join ",", values %{$_[0]});
$function$
and then
create index on profile (len_immut(profile));
SELECT * FROM profile ORDER BY len_immut(profile) DESC;
Since the function is falsely labelled as immutable, the index may become out of date if you do things like add or drop columns on the table, or change the types of columns.
I have a use case where i am mapping two tables to the same object.
In this object i have a string called source and I want to be able to set the table name or the database name to this variable.
Any ideas on how to achieve this?
I have thought about iterating over my list and manually setting it but this has the potential to waste a fair chunk of time.
I appreciate this is somewhat of an odd request so this may be the only way but am hoping for a solution that maps the source variable when hibernate is mapping everything else.
if i had understood correctly your issue , then your solution might be the MappedSuperClass , in which you must have an abstract class , which will have the common fields of the two tables and then you will extend that to the two entities you want , which will point to two different tables.
Check this link
You could try to achieve this with Load listener or Interceptors. In the listener/interceptor you can check what the data source is and populate the source field accordingly.
In the end i ended up using a formula to map my variable to a select statement which was sufficient for what i needed.
1.In my application there is a requirement to display certain value (among the 3 different values) in each row of the table column,the value to be displayed in each row can be decided by checking the values of two different model key paths.
This i tried to implement using bindings,where i used "Display pattern Value1 with one key path and custom value transformer class" and "Display pattern Value2 with other key path and same value transformer".But i am not getting desired output value from the transformer class.Can anyone please help me in resolving this issue.
2.In the other application there is a table view with 3 columns,where the first column displays the complete word,second column displays the prefix of that word and the third column displays the suffix of that word.
I implemented this requirement using bindings and two custom value transformer classes.One for getting the prefix of the word(prefixExtractor) and the other for getting the suffix of the word(suffixExtractor).Can anyone suggest me how can i implement this requirement using only one custom value transformer class so that it optimizes my code.
Thanks in advance.
Say I have an entity MyEntity, and it has a formula-based property fmlaProp. Now say I create a criteria:
s.createCriteria(MyEntity.class)
.setProjection(
Projections.distinct(
Projections.property("fmlaProp")))
.addOrder(Order.asc("fmlaProp"));
in this case I get the following SQL:
SELECT DISTINCT fmlaProp-sql FROM MY_ENTITY_TABLE ORDER BY fmlaProp-sql
Which gives an error on Oracle saying that order-by expression is non-selected. Then I tried the following criteria:
s.createCriteria(MyEntity.class)
.setProjection(
Projections.distinct(
Projections.alias(
Projections.property("fmlaProp"),
"alias1"))
.addOrder(Order.asc("alias1"));
Which generates "order by alias1" which works fine. But it is kind of ugly -- the code must "know" of those formula properties, which violates "write once" principle. Any thoughts or suggestions on that? Thank you in advance.
This is expected behavior from Hibernate. It doesn't have to do with the formula property specifically, but that you want to do ordering with a projected value. From the Hibernate Docs:
An alias can be assigned to a projection so that the projected value can be referred to in restrictions or orderings. Here are two different ways to do this...
As far as alternatives, you could try making the formula property a virtual column (in versions of Oracle 11 and above) or wrapping the table in a view with this column computed. That way, Oracle will know fmlaprop directly, which can be used just like a "normal" column.
I created an element with an input value of type "Day" , when i write a formula i get this error.
Any idea what's wrong?
APP-FF-33232:
EATC_EXTRA_DAYS_ENTRY_EFFECTIVE_DATE_ENTRY_VALUE has null or not found allowed, but no
default set specified.
Cause: If a Database Item has
null allowed, or not found allowed,
then the item must also specify a
default set to be used to provide
default values in the event of these
occurring. The item named has one of
these conditions allowed, but the
default set column in the
FF_DATABASE_ITEMS table is null.
Action: Please refer to your
local support representative.
-
I'm not an expert in Oracle Apps (to say the least) but the error message is fairly clear. You - or someone - have written a Fast Formula which references a database column EATC_EXTRA_DAYS_ENTRY_EFFECTIVE_DATE_ENTRY_VALUE. Apparently this column can be nullable, in which case your Formula needs to provide a default value. Something like:
default for EATC_EXTRA_DAYS_ENTRY_EFFECTIVE_DATE_ENTRY_VALUE is 01-JAN-2010
Or perhaps you can use SYSDATE or CURRENT_DATE rather than a fixed value.
Solution to error: You called database item in Fast formula,
you need to initialize the date to specific date
alias EATC_EXTRA_DAYS_ENTRY_EFFECTIVE_DATE_ENTRY_VALUE as day
default for day is 01-jan-2010