Let's suppose we have some class which is related to one or more codes: main and secondary. Every object of this class has at least main code and can have unlimited number of secondary codes:
class Something {
private String mainCode;
private List<String> secondaryCodes;
}
I want to make a rule in Drools decision table which allows me to check if value given in column is equal to mainCode or is contained by secondaryCodes.
So I need one column for two rules related to two different fields.
Is it even possible?
The constraint can be written as a compound Boolean expression:
mainCode == $param || secondaryCodes contains $param
There's no restriction as to the fields you refer to in such an expression.
You can do this in Guvnor using #{param} in a Condition BRL fragment like:
$s : Something (maincode == "#{codes}" || secondaryCodes contains "#{codes}"
That gives you one column.
-J
Related
As a part of reporting I want to get some values from database.
Also I included filtering in report UI, like :
select * from invoice where id in (92)
So I am making the postgres statement dynamically(here 92 is the value getting from UI and assigning dynamically). But I want to return all data without any condition if the user select no option, id in this case (no filtering). So how can I handle the "in" clause to return all data without any filtering in this case.
I am asking for a common term that can be included in 'in' clause, so it retun all rows without filtering.
Thanks!
One method is using logic like:
where (v_id is null) or (id = v_id)
Note: be careful about the use of in. It probably will not do what you intend if you expect multiple values to match.
Given this perl DBI query:
$qh = $db_connection->prepare ('SELECT addresses.* from addresses WHERE 1');
The addresses table structure might change in the future, that is, some new columns may get inserted into it. So there's no guarantee which index number a particular column may get assigned to.
When I do a $qh->fetchrow_array, I want to be able to determine what the index number of a particular column is so I can check to see if it's empty. For example, I want to see if the mail_addr column is empty like so:
if (!$$row[$index_number]) {
do_something();
}
How can I determine what the value $index_number should be?
This can be determined via $sth->{NAME}. However, this situation is probably more appropriate for fetchrow_hashref which implements all the gluing of indices to field names you're looking for:
while ( my $row = $qh->fetchrow_hashref ) {
if (!$row->{mail_addr}) {
do_something();
}
}
Also consider the FetchHashKeyName attribute, fetchrow_hashref('NAME_lc'), or the $sth->{NAME_lc} attribute, which will guarantee the case of fieldnames presented by the DBI. Different SQL engines will normalize the identifier case differently, often depending on whether the identifier was quoted when declared.
Firstly, please don't use the $$row[$index_number] syntax. Anyone looking at your code will be expecting to see that written as $row->[$index_number].
You've worked out why SELECT * is a bad idea. So don't do that. List the specific columns that you are interested in - that way you can impose your own order (fetchrow_array returns columns in the order that they appear in the SELECT clause).
Alternatively, switch to one of the hash-based fetch methods like fetchrow_hashref.
But the best alternative would be to look at using DBIx::Class.
In this Drools sheet I am comparing a class variable with a variable of another class variable but the rule converted are not as expected. Is there a way to do this...
One thing is creating a problem and it is when this excel sheet is converted into rules the condition where I check stdId in college class is equals to id of Student class i.e. third column, the rule is generated as follows-
$c2: College(stdId == $s.id == "x")
The =="x" part is undesirable and creating trouble while running the rules.
What should be done to remove the extra undesired part.
The third column can be written as
CONDITION
$c2: College(stdId==$s.id)/*$param*/
match student id
x
x
...
The x is required to trigger insertion of the conditional expression from row 2.
I would like to perform the function of a Calculate Sum rule with a Script rule in ABBYY Flexicapture, because I want to only perform the calculation based on evaluation of an if statement.
I have tried the following in a C# script rule:
IFields AllTaxes = Context.Field("cu_location_taxes").Rows;
which gives me the error "Field is not a table."
I have also tried
IFields AllTaxes = Context.Field("cu_location_taxes").Children;
which gives me the error "Cannot access fields not specified in rule settings." Even though I have added the repeating group cu_location_taxes to the c# script rule.
Once I am able to get them in some kind of array or list or IFields variable, I would like to sum the children values in some way. I am open to doing this with JScript or C#.
The reasons of the errors you are facing can be found in ABBYY FlexiCapture Help.
In the description of IField class you can find the following descriptions of properties:
Rows - A set of table rows. Unavailable for non-table fields.
Well, it seems to be that "cu_location_taxes" is not a table. You said, it is a repeating group.
Children - Child items of the field (cells for tables). Unavailable in script rules.
But as I understand, you are exactly using script rules.
To achieve correct results try to use Items property exactly of the fields that you are summing.
For example, you have a repeating group that contains number fields field_1 and field_2. And you want to calculate the sum of all field_1 instances.
Then you can use the following code (JScript):
sum = 0
for (i = 0; i < this.Field("field_1").Items.Count; ++i)
{
sum += this.Field("field_1").Items.Item(i).Value
}
Also do not forget to add the field_1 in available fields of your rule settings.
Hope this will help.
I am using the fatfree framework, and on the front-end I am using jQuery datatables plugin with server-side processing. And thus, my server-side controller may or may not receive a variable number of information, for example a variable number of columns to sort on, a variable number of filtering options and so forth. So if I don't receive any request for sorting, I don't need to have a ORDER BY portion in my query. So I want to generate the query string in parts as per certain conditions and join it at the end to get the final query for execution. But if I do it this way, I won't have any data sanitization which is really bad.
Is there a way I can use the frameworks internal sanitization methods to build the query string in parts? Also is there a better/safer way to do this than how I am approaching it?
Just use parameterized queries. They are here to prevent SQL injection.
Two possible syntaxes are allowed:
with question mark placeholders:
$db->exec('SELECT * FROM mytable WHERE username=? AND category=?',
array(1=>'John',2=>34));
with named placeholders:
$db->exec('SELECT * FROM mytable WHERE username=:name AND category=:cat',
array(':name'=>'John',':cat'=>34));
EDIT:
The parameters are here to filter the field values, not the column names, so to answer more specifically to your question:
you must pass filtering values through parameters to avoid SQL injection
you can check if column names are valid by testing them against an array
Here's a quick example:
$columns=array('category','age','weight');//columns available for filtering/sorting
$sql='SELECT * FROM mytable';
$params=array();
//filtering
$ctr=0;
if (isset($_GET['filter']) && is_array($_GET['filter'])
foreach($_GET['filter'] as $col=>$val)
if (in_array($col,$columns,TRUE)) {//test for column name validity
$sql.=($ctr?' AND ':' WHERE ')."$col=?";
$params[$ctr+1]=$val;
$ctr++;
}
//sorting
$ctr=0;
if (isset($_GET['sort']) && is_array($_GET['sort'])
foreach($_GET['sort'] as $col=>$asc)
if (in_array($col,$columns,TRUE)) {//test for column name validity
$sql.=($ctr?',':' ORDER BY ')."$col ".($asc?'ASC':'DESC');
$ctr++;
}
//execution
$db->exec($sql,$params);
NB: if column names contain weird characters or spaces, they must be quoted: $db->quote($col)