That sounds like what is going on. I'll give that a shot tomorrow. Thanks
Chuck.
Sent from my iPhone
> On Mar 19, 2017, at 2:59 AM, Chuck Hill <ch...@gevityinc.com> wrote:
>
> Hi Ricardo,
>
> You need to create a branch (push from your local) in your GitHub fork of
> Wonder for each set of changes in GitHub (aka a Feature Branch), then make a
> pull request from that branch to Wonder. Otherwise all of your changes get
> inter-mixed.
>
> Chuck
>
>
> From: Ricardo Parada <rpar...@mac.com>
> Date: Saturday, March 18, 2017 at 11:22 PM
> To: "webobjects-dev@lists.apple.com" <webobjects-dev@lists.apple.com>
> Cc: Markus Ruggiero <mailingli...@kataputt.com>, Paul Hoadley
> <pa...@logicsquad.net>, "koa...@icloud.com" <koa...@icloud.com>,
> "g...@knuckleheads.net" <g...@knuckleheads.net>, Chuck Hill
> <ch...@gevityinc.com>, "aa...@chatnbike.com" <aa...@chatnbike.com>
> Subject: Re: ERXQuery Preview
>
> Hi all,
>
> As promised, I have committed ERXQuery to my Wonder clone on GitHub, i.e.
> rparada/wonder. I just need help creating the pull request. :-)
>
> It turns out that I created first a pull request for ERXExtensions.java
> unrelated to ERXQuery. Now when I tried to create the pull request for
> ERXQuery it just seems to show the previous pull request. So I’m not sure
> what is going on. I don’t have much experience with GitHub.
>
> Anyways, the ERXQuery is an additive change to Wonder and consists of only
> three files: ERXQuery.java, ERXQueryAttributes and ERXQueryEOAttribute. It’s
> the last two commits in rparada/wonder.
>
> I took the time to polish the API a bit more. I think the API came out nicer
> than what I had the first time around. Specially the single variadic
> select() method that allows you to specify EOAttributes, Strings, ERXKeys, or
> any Iterable containing these. Same for groupBy(). And the a similar
> technique with the orderBy() which can take EOSortOrderings or any Iterable
> (ERXSortOrderings, NSArray, List, Collection).
>
> The documentation is more extensive now. I have included here a copy of the
> ERXQuery class from the javadoc tab in my Eclipse.
>
> I have tested with ORACLE which is the easiest for me to test. It would be
> great to hear others using this with other databases (h2, derby, mssql,
> mysql, frontbase, etc.)
>
>
> ERXQuery.java
> Overview
> This class has a fluent API that mimics a select statement:
>
> NSArray<NSDictionary<String,Object>> records =
> ERXQuery.create()
> .select (keys)
> .from (entity)
> .where (qualifier)
> .groupBy (groupings)
> .having (havingQualifier)
> .orderBy (sortings)
> .fetch();
>
> It allows you to use EOF/Wonder higher-level constructs (qualifiers,
> attributes, orderings, key paths, ERXKeys, etc.) to create a query that looks
> like this:
>
> SELECT ...
> FROM ...
> WHERE ...
> GROUP BY ...
> HAVING ...
> ORDER BY ...
>
>
> Specifying the Attributes to Fetch
> The select() method is very flexible and powerful. It accepts a variable
> number of objects of different types that specify the attributes to fetch.
> These objects can be EOAttributes, ERXKeys, Strings. You may also specify
> NSArray or List objects containing any combination of these (EOAttributes,
> ERXKeys, Strings).
>
> The ERXKeys and String objects correspond to keys and key paths to the
> attributes to fetch, i.e. "customer.name". The keys and key paths can also be
> relationships to objects, i.e. "customer" which translate into a fetch of
> foreign keys used to build object faults and return them in the results.
>
> You may call the select() method multiple times to keep adding to the list of
> attributes to fetch.
>
> Using Ad Hoc Attributes
> It is very common to aggregate attributes in these queries. For this purpose,
> you may want to create what ERXQuery refers to as ad hoc attributes. These
> attributes have a definition but are not physically attached to the entity.
> You can use the ERXQueryAttributes class to easily create multiple ad hoc
> attributes. The definition of the attribute can reference relationships and
> attributes as shown below. If you just want to create a single ad hoc
> attribute you may use the ERXQueryEOAttribute class.
>
> // Using a single query against the order entity to count the number of
> // orders and line items that match an order qualifier.
>
> ERXQueryAttributes attributes = ERXQueryAttributes.create(orderEntity)
> .add("itemCount", "COUNT(DISTINCT lineItems.lineItemID)", "intNumber")
> .add("orderCount", "COUNT(DISTINCT orderID)", "intNumber");
>
> ERXQuery query =
> ERXQuery.create()
> .select (attributes)
> .from (orderEntity)
> .where (qualifier);
>
> // Fetch into a dictionary
> NSDictionary<String,Object> row = query.fetch().lastObject();
>
> int orderCount = ((Number) row.objectForKey("orderCount")).intValue();
> int itemCount = ((Number) row.objectForKey("itemCount")).intValue();
>
> Fetching Results into a Custom Class
> It is useful to fetch results into objects of a custom class. This allows you
> to have type checking on the getter methods and add methods for computed
> values on the data fetched. For the example above you could have fetched the
> results into a custom class as follows:
>
> // Fetch into object instances of the a custom Result class
> Result result = query.fetch(editingContext, Result.class).lastObject();
> int orderCount = result.orderCount();
> int itemCount = result.itemCount();
>
> The Result custom class would have to be defined as shown below. The
> constructor may keep the mutable dictionary passed in to the constructor or
> make an immutable copy from it as shown below.
>
> public static class Result {
> NSDictionary<String,Object> data;
>
> public Result(EOEditingContext ec, NSMutableDictionary<String,Object>
> row) {
> data = row.immutableClone();
> }
>
> public int itemCount() {
> return ((Number) data.objectForKey("itemCount")).intValue();
> }
> public int orderCount() {
> return ((Number) data.objectForKey("orderCount")).intValue();
> }
> }
> }
>
> In general, fetching into a custom class can be done in several ways:
> // If your custom class has a constructor that takes an editing context and
> // a mutable dictionary then it is very simple:
> NSArray<Foo> objs = query.fetch(editingContext, Foo.class);
>
> // Using java 8 or later you may use a lambda expression:
> NSArray<Foo> objs = query.fetch(editingContext, (ec, row) -> new Foo(ec,
> row));
>
>
> // You may also create an implementation of the RecordConstructor
> // functional interface and pass it into the fetch method:
> ERXQuery.RecordConstructor<Foo> recordConstructor =
> new ERXQuery.RecordConstructor<Foo> {
> @Override
> public Foo constructRecord(EOEditingContext ec, NSMutableDictionary
> row) {
> return new Foo(ec, row);
> }
> };
> NSArray objs = query.fetch(editingContext, recordConstructor)
> }
>
> Augmenting Row Values
> You can have entries from a dictionary added in to the rows fetched from the
> database. The mutable dictionary passed in to the record constructor will
> contain the data fetched along with the keys/values from this
> recordInitializationValues dictionary.
>
> NSDictionary<String,Object> recordInitializationValues = new
> NSDictionary<>((Object)2017, "preferredYear");
> NSArray<Foo> objs = query.fetch(editingContext, recordInitializationValues,
> Foo.class);
> Foo aFoo = objs.lastObject();
> int preferredYear = aFoo.preferredYear(); // i.e. 2017
>
> Defining Ad Hoc Attributes in the Entity
> An alternate way to define your ad hoc attributes is to define them in your
> entity and flagging them as non-class properties. Unlike ERXQueryEOAttribute
> objects, these attributes will be instances of EOAttribute and reside in your
> entity. They may be a bit distracting when looking at the entity if you have
> a lot but this method allows you to reuse all the existing attributes and
> relationships already defined in the entity and does not require code for
> creating the attributes.
>
> One incovenience is that eogeneration templates do not generate ERXKeys for
> non-class properties. However, this problem could be overcome by enhancing
> the eogeneration templates to generate ERXKeys for derived non-class property
> attributes.
>
> // Fetch last year's customer order totals exceeding $1000 in descending
> order
> NSArray<OrderSummary> lastYearTopSales =
> ERXQuery.create()
> .select (Order.CUSTOMER) // customer to-one
> .select (Order.SUM_TOTAL_AMOUNT) // non-class property defined
> as SUM(totalAmount)
> .from (Order.ENTITY_NAME)
> .where (lastYearQualifier)
> .groupBy (Order.CUSTOMER)
> .having (Order.SUM_TOTAL_AMOUNT.greaterThan(1000.00))
> .orderBy (Order.SUM_TOTAL_AMOUNT.desc())
> .fetch(editingContext, OrderSummary.class);
>
> // Peek at top sale record
> OrderSummary topSale = ERXArrayUtilities.firstObject(lastYearTopSales);
> if (topSale != null) {
> System.out.println("Customer " + topSale.customer().fullName()
> + " ordered " + moneyFormatter.format(topSale.sumTotalAmount()));
> }
> }
>
> It would be nice to enhance the eogeneration templates to also create a
> custom class for fetching the results, i.e. WonderEntitySummary.java and
> _WonderEntitySummary.java with the getters for attributes/relationships in
> the entity including derived non-class properties. These templates would be
> used when the entity has a user info key with ERXQuery.enabled=yes.
>
> Limitations
> Ad hoc attributes created with ERXQueryAttributes or ERXQueryEOAttribute are
> not physically attached to an entity. When EOF generates SQL for a qualifier
> it calls sqlStringForSQLExpression(q,e) where q is an EOQualifier and e is an
> EOSQLExpression. Qualifiers then try to reach the attribute by following the
> qualifier's referenced keys starting with the entity of the EOSQLExpression,
> i.e. e.entity().
>
> The current workaround used by ERXQuery is to temporarily add to the entity
> any ad hoc attributes referenced by the qualifiers. This typically happens
> with the havingQualifier which normally references the ad hoc attributes
> corresponding to aggregated attributes. For example, "sumTotalAmount" defined
> as "SUM(totalAmount)" could be used in a having qualifier:
>
> // When grouping orders by customer and fetching sumTotalAmount we may want
> to have
> // this having qualifier so that we only fetch the groups totaling more
> than 1000.
> EOQualifier havingQualifier = ERXQ.greaterThan("sumTotalAmount", new
> BigDecimal(1000.0));
>
> However, if you were to define your "sumTotalAmount" attribute in your entity
> as a derived non-class property with definition "SUM(totalAmount)" then
> ERXQuery doesn't have to add the attribute to the entity.
>
> Defaults for Behavior Properties
> 1. er.extensions.eof.ERXQuery.useBindVariables=false
> 2. er.extensions.eof.ERXQuery.useEntityRestrictingQualifiers=true
> 3. er.extensions.eof.ERXQuery.removesForeignKeysFromRowValues=true
> Author:
> Ricardo J. Parada
>
>
>
> On Mar 14, 2017, at 8:31 AM, Ricardo Parada <rpar...@mac.com> wrote:
>
>
>
> Thanks all for the feedback. I'll be adding it by the weekend I hope.
>
>
> On Mar 14, 2017, at 4:29 AM, Markus Ruggiero <mailingli...@kataputt.com>
> wrote:
>
> Great thing, looks very useful.
>
> On 11.03.2017, at 23:41, Ricardo Parada <rpar...@mac.com> wrote:
>
> Hi all,
>
> Over the years, I’ve worked on an class for doing ad hoc queries. This class
> has gotten better and better. At first, the API of this class and some
> implementation details were not ready for public consumption in my opinion.
>
> However, recently I took the time to polish the code as much as possible and
> if I can get my employer's approval I would like to contribute this code to
> project Wonder which has given us so much in return during the years.
>
> Here is a preview of its functionality. Please let me know if you guys think
> this would be a useful contribution.
> ERXQuery.java
> This class has a fluent API that mimics a select statement:
> NSArray<NSDictionary<String,Object>> records =
> ERXQuery.create()
> .select (keys)
> .from (entity)
> .where (qualifier)
> .groupBy (groupings)
> .having (havingQualifier)
> .orderBy (sortings)
> .fetch();
> Overview
> ERXQuery allows you to use EOF constructs (EOQualifiers, EOAttributes,
> EOSortOrdering, EOAttribute names, relationships, etc.) to create queries of
> the form:
> SELECT ...
> FROM ...
> WHERE ...
> GROUP BY ...
> HAVING ...
> ORDER BY ...
> Using Ad Hoc Attributes
> You may use the ERXAdHocAttributes class to easily create ad hoc attributes
> to use with your query. For example, the code below creates two ad hoc
> EOAttributes. An ad hoc attribute is an EOAttribute that is not physically
> attached to an entity and that has a definition. They are useful for
> aggregating other attributes. The definition of the attribute can reference
> relationships and attributes as shown below.
> // Using a single query against the order entity, count the number of
> // orders and line items that match the qualifier.
> ERXAdHocAttributes attributes = ERXAdHocAttributes.create(orderEntity)
> .add("itemCount", "COUNT(DISTINCT lineItems.lineItemID)", "intNumber")
> .add("orderCount", "COUNT(DISTINCT orderID)", "intNumber");
> NSDictionary<String,Object> row =
> ERXQuery.create()
> .select (attributes)
> .from (orderEntity)
> .where (qualifier)
> .fetch()
> .lastObject();
> int orderCount = ((Number) row.objectForKey("orderCount")).intValue();
> int itemCount = ((Number) row.objectForKey("itemCount")).intValue();
> Fetching into a Custom Record Class
> You can also fetch using a custom class of your choice, i.e. Foo, as shown
> below:
> // Using java >= 8 is easy with a lambda expression
> NSArray<Foo> objs = query.fetch(editingContext, (ec, row) -> new Foo(ec,
> row));
>
> // Using java < 8 you must provide a RecordConstructor
> ERXQuery.RecordConstructor<Foo> recordConstructor =
> new ERXQuery.RecordConstructor<Foo> {
> @Override
> public Foo constructRecord(EOEditingContext ec, NSMutableDictionary
> row) {
> return new Foo(ec, row);
> }
> };
> NSArray objs = query.fetch(editingContext, recordConstructor);
> Author: Ricardo J. Parada
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>
>
> Markus Ruggiero
> mailingli...@kataputt.com
> Check out the new book about Project Wonder and WebObjects on
> http://learningthewonders.com/
>
>
>
>
>
>
>
>
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