May I know how to convert the following MySQL SQL to JPA query?
SELECT * FROM ORDER
WHERE LPAD(BATCH, 2, ' ') < LPAD('X', 2, ' ') ;
What I couldn't figure out is the LPAD() string function in JPA.
Do you have any idea?
I know that is a very old post, but i am always be questioned by some colleagues when they are building JPA queries how to do the same thing.
Almost never you will find a perfect fit function to do what do you want. But, using some logic you can get the same result, in full JPA.
A example of LPAD.
Expression<String> numberWithZeroLeft = builder.concat("0000", root.get("myNumber")); //Return something like 000012
Expression<Integer> expressionLength = builder.length(numberWithZeroLeft);
Expression<String> numberLpad = builder.substring(numberWithZeroLeft, e.builder.sum(expressionLength, -3), e.builder.literal(4)); //Return something like 0012
query.select(numberLpad);
Think in something like:
I have a string X, and need a string formatted in 4 zeros.
So we will get 0000 + X => "0000X"
And now just get the 4 last characters using substring.
I hope that help someone.
Cheers. =]
In EclipseLink 2.1 there is a function FUNC for calling database specific functions, for example:
FUNC('LPAD', BATCH, 2, ' ') < FUNC('LPAD', 'X', 2, ' ')
From EclipseLink 2.4 and JPA 2.1 there is FUNCTION operator with the same functionality
Related
I've been given data to build an application that has sequential data in the form of part numbers of products: "000000", "000001", "000002", "000010", "000011" .... The previous application was an old MS Access database that didn't have any gap filling features in the part number generator, hence the gap between "000002" and "000010" (Yes, they are also strings, but I can work with that...).
We could continue to increment based on the last value and ignore the gaps, however, in an attempt to use all numbers available to us with our naming scheme, we'd like to be able to fill the gaps. Our naming scheme describes the "product family" with the first two digits such that: [00]0000 would be a different family from [02]0000.
I can find the starting and ending values using something like:
let query = `
LET first = (
MIN(
FOR part in part_search
SEARCH STARTS_WITH(part.PartNumber, #family)
RETURN part.PartNumber
)
)
LET last = (
MAX(
FOR part in part_search
SEARCH STARTS_WITH(part.PartNumber, #family)
RETURN part.PartNumber
)
)
RETURN { first, last }
`
The above example returns: {first: "000000", last: "000915"}
Using ArangoDB and AQL, how could I go about finding these gaps? I've found some SQL examples but I feel the features of AQL are a bit more limiting.
Thanks in advance!
To start with, I think your best bet for getting min/max values is using aggregates:
FOR part in part_search
SEARCH STARTS_WITH(part.PartNumber, #family)
COLLECT x = 1
AGGREGATE first = MIN(part.PartNumber), last = MAX(part.PartNumber)
RETURN {
first: first,
last: last
}
But that won't really help when trying to find gaps. And you're right - SQL has several logical constructs that could help (like using variables and cursor iteration), but even that would be a pattern I would discourage.
The better path might be to do a "brute force" approach - compare a table containing your existing numbers with a table of all numbers, using a native method like JOIN to find the difference. Here's how you might do that in AQL:
LET allNumbers = 0..9999
LET existingParts = (
FOR part in part_search
SEARCH STARTS_WITH(part.PartNumber, #family)
LET childId = RIGHT(part.PartNumber, 4)
RETURN TO_NUMBER(childId)
)
RETURN MINUS(allNumbers, existingParts)
The x..y construct creates a sequence (an array of numbers), which we use as the full set of possible numbers. Then, we want to return only the "non-family" part of the ID (I'm calling it "child"), which needs to be numeric to compare with the previous set. Then, we use MINUS to remove elements of existingParts from the allNumbers list.
One thing to note, that query would return only the "child" portion of the part number, so you would have to join it back to the family number later. Alternatively, you could also skip string-splitting, and get "fancy" with your list creation:
LET allNumbers = TO_NUMBER(CONCAT(#family, '0000'))..TO_NUMBER(CONCAT(#family, '9999'))
LET existingParts = (
FOR part in part_search
SEARCH STARTS_WITH(part.PartNumber, #family)
RETURN TO_NUMBER(part.PartNumber)
)
RETURN MINUS(allNumbers, existingParts)
I am stuck to find out better one between str() and format() in python
"SELECT schools.deis_income , schools.school_name,SUM(money.coin_in_amount) AS coinamount, SUM(money.note_in_amount) AS noteamount , SUM(money.coffee_coin_in_amount) AS coffeeamount , SUM(money.coin_out_amount) AS coinoutamount, SUM(money.note_out_amount) AS noteoutamount FROM money_transactions AS money JOIN school_admin_details AS sa on sa.id = money.school_admin_id JOIN schools ON schools.id=sa.school_id WHERE sa.school_id ={school_id} AND money.transaction_time BETWEEN '{start_date}' AND '{end_date}' GROUP BY schools.id".format(school_id=school_id,start_date=start_date,end_date=end_date)
I use format function here. can I use str() ?
please tell me which one give me quick result, str() or format() ???
If your question is which of this:
foo = "some text " + str(some_var) + " and some other text"
or this:
foo = "some text {} and some other text".format(var)
is "better", the general consensus is very clear: string formatting is much easier to read and maintain and the one pythonic way to go.
Now for your particular example, the answer is that both are totally wrong - unless you're ok to give full access to your database to even the most inept script kiddie. For SQL queries, the proper solution is to use prepared statements, where your db connector will take care of proper formatting and sanitizing of the values:
# assumes MySQL - for other vendors check your own
# db-api connector's doc for the correct placeholder
query = "SELECT somefield FROM mytable where somedate > %(somedate)s and something_else = %(someval)s"
cursor.execute(query, {"somedate": some_date, "someval": 42})
I need to get the value that is between !03 and !03.
Example:
JDC!0320151104!03OUT
I should get following string in return: 20151104
NOTE: The string isn't always 22 characters long, but I am only concerned with the value that is between !03 and !03.
This is what I have so far. I couldn't make any progress further than this:
SELECT
SUBSTRING(
RegStatsID,
CHARINDEX('!', RegStatsID) + 3,
CHARINDEX('!', REVERSE(RegStatsID))
)
From TableX
Great that you found a solution!
This might be better:
By replacing the "!03" with XML-tags you can easily pick the second "node". Your string will be transformed into <x>JDC</x><x>20151104</x><x>OUT</x>:
DECLARE #test VARCHAR(100)='JDC!0320151104!03OUT';
SELECT CAST('<x>' + REPLACE(#test,'!03','</x><x>') + '</x>' AS XML).value('/x[2]','datetime')
One advantage was to get the value between the two "!03" typed. In this case you get a "real" datetime back without any further casts. If the value there is not a datetime (or date) in all cases, you just use nvarchar(max) as type.
Another advantage was: If you - why ever - need the other values later, you just have them with .value('/x[1 or 3]'...)
I was able to get it right by doing following:
SELECT
SUBSTRING(
RegStatsID,
CHARINDEX('!', RegStatsID) + 3,
len(RegStatsID) - CHARINDEX('!', RegStatsID ) - 2 - CHARINDEX('!', Reverse(RegStatsID))
)
I have a string field with mostly numeric values like 13.4, but some have 13.4%. I am trying to use the following expression to remove the % symbols and retain just the numeric values to convert the field to integer.
Here is what I have so far in the expression definition of Cognos 8 Report Studio:
IF(POSITION('%' IN [FIELD1]) = NULL) THEN
/*** this captures rows with valid data **/
([FIELD1])
ELSE
/** trying to remove the % sign from rows with data like this 13.4% **/
(SUBSTRING([FIELD1]), 1, POSITION('%' IN [FIELD1])))
Any hints/help is much appreciated.
An easy way to do this is to use the trim() function. The following will remove any trailing % characters:
TRIM(trailing '%',[FIELD1])
The approach you are using is feasable. However, the syntax you are using is not compatible with the version of the ReportStudio that I'm familiar with. Below you will find an updated expression which works for me.
IF ( POSITION( '%'; [FIELD1]) = 0) THEN
( [FIELD1] )
ELSE
( SUBSTRING( [FIELD1]; 1; POSITION( '%'; [FIELD1]) - 1 ) )
Since character positions in strings are 1-based in Cognos it's important to substract 1 from the position returned by POSITION(). Otherwise you would only cut off characters after the percent sign.
Another note: what you are doing here is data cleansing. It's usually more advantageous to push these chores down to a lower level of the data retrieval chain, e.g. the Data Warehouse or at least the Framework Manager model, so that at the reporting level you can use this field as numeric field directly.
I have this strange problem. i have a table with 10 columns of type character varying.
I need to have a function that searches all records and returns the id of the record which has all strings. Lets say records:
1. a,b,c,d,e
2. a,k,l,h
3. f,t,r,e,w,q
if i call this function func(a,d) it should return 1, if i call func(e,w,q) its should return 3.
The function is
CREATE OR REPLACE FUNCTION func(ma1 character varying,ma2 character varying,ma3 character varying,ma4 character varying)
DECLARE name numeric;
BEGIN
SELECT Id INTO name from Table WHERE
ma1 IN (col1,col2,col3,col4) AND
ma2 IN (col1,col2,col3,col4) AND
ma3 IN (col1,col2,col3,col4) AND
ma4 IN (col1,col2,col3,col4);
RETURN name;
END;
It's working 90% of the time, the weird problem is that some rows are not found.
Its not uppercase or lowercase problem.
What can be wrong, its version 9.1 on 64 bit win 7. I feel its like encoding or string problem but i can't see where and what.
//Ok i found the problem, it has to do with all column, if all 24 columns are filled in then its not working ?? but why ? are there limitations becouse there are 24 columns that i must compare with//
Can someone help me plz.
thanks.
The problem is (probably) that some of your columns have nulls.
In SQL, any equality comparison with a null is always false. This extends to the list of values used with the IN (...) condition.
If any of the values in the list are null, the comparison will be false, even if the value being sought is in the list.
The work-around is to make sure no values are null. which unfortunately results in a verbose solution:
WHERE ma1 IN (COALESCE(col1, ''), COALESCE(col2, ''), ...)
I suspect Bohemian is correct that the problem is related to nulls in your IN clauses. An alternative approach is to use Postgres's array contained in operator to perform your test.
where ARRAY[ma1,ma2,ma3,ma4] <# ARRAY[col1,col2,...,colN]