I have the following code which is in a base class.
MyApp.MyDB = new MyApp.MyDB ();
IRepository<T> repo = new SubSonicRepository<T>(db);
CurrentTable = repo.GetTable();
var s = db.SelectColumns(columnList.ToArray()).
From(CurrentTable.Name).
OrderAsc(CurrentTable.Descriptor.Name);
The idea is that all my classes can call this method.
I have just realised that I may need to a 'where' statement and there could be numerous columns names and values to test for.
What's the best approach for this?
UPDATE: I found this works below but is it best practice?
//WhereClause is a Dictionary<string, string>
int count = 0;
foreach (var whereitem in WhereClause)
{
if (count == 0)
{
s.Where(whereitem.Key).IsEqualTo(whereitem.Value);
}
else
{
s.And(whereitem.Key).IsEqualTo(whereitem.Value);
}
count++;
}
This simplifies the logic slightly: For the where clause, do something like this:
s.Where(1).IsEqualTo(1);
For all your other whereitem's, you can use And's.
Related
I'm using my OrganizationServiceContext implementation generated by the svcutil to retrieve entities from CRM:
context.new_productSet.First(p => p.new_name == "Product 1");
Is it possible to retrieve multiple entities with different attribute values at once - (smth like IN operator in SQL)?
Example: I would like to retrieve multiple products ("Product 1", "Product 2", ...) with a single call. The list of product names is dynamic, stored in an array called productNames.
No, you can't. CRM LINQ provider only allows variables to appear on the left side of expressions, while the right side must contain constants.
i.e.
Product.Where(e => e.Name == desiredName)
Is not supported and won't work (it will complain about using a variable on the right side of the comparison).
If you cannot avoid this kind of query, you have to .ToList() data first (this can lead to a huge result set and will probably turn up to be unconceivably slow):
Product.ToList().Where(e => e.Name == desiredName)
This will work, because now the .Where() is being applied on a List<> instead.
Another approach (I don't have data about performance, though) would be to create many queries, basically fetching the records one at a time:
// ... this is going to be a nightmare ... don't do it ...
var entities = new List<Product>();
entities.Add(Product.Where(e => e.Name == "Product 1"));
entities.Add(Product.Where(e => e.Name == "Product 2"));
Or use a QueryExpression like this (my personal favourite, because I always go late-bound)
var desiredNames = new string[]{"Product 1", "Product 2"};
var filter = new FilterExpression(LogicalOperator.And)
{
Conditions =
{
new ConditionExpression("name", ConditionOperator.In, desiredNames)
}
};
var query = new QueryExpression(Product.EntityLogicalName)
{
ColumnSet = new ColumnSet(true),
Criteria = filter
};
var records = service.RetrieveMultiple(query).Entities;
If combining Linq and Lambda expression is ok, it can be done. First you need to create an extension method:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
namespace Kipon.Dynamics.Extensions.IQueryable
{
public static class Methods
{
public static IQueryable<TSource> WhereIn<TSource, TValue>(this IQueryable<TSource> source, Expression<Func<TSource, TValue>> valueSelector, IEnumerable<TValue> values)
{
if (null == source) { throw new ArgumentNullException("source"); }
if (null == valueSelector) { throw new ArgumentNullException("valueSelector"); }
if (null == values) { throw new ArgumentNullException("values"); }
var equalExpressions = new List<BinaryExpression>();
foreach (var value in values)
{
var equalsExpression = Expression.Equal(valueSelector.Body, Expression.Constant(value));
equalExpressions.Add(equalsExpression);
}
ParameterExpression p = valueSelector.Parameters.Single();
var combined = equalExpressions.Aggregate<Expression>((accumulate, equal) => Expression.Or(accumulate, equal));
var combinedLambda = Expression.Lambda<Func<TSource, bool>>(combined, p);
return source.Where(combinedLambda);
}
}
}
With this method in place, you can now use it against your context. First remember to import the namespace of the extension to make the method available on IQueryable:
using System.Linq;
using Kipon.Dynamics.Extensions.IQueryable;
public class MyClass
{
void myQueryMethod(CrmContext ctx, Guid[] contacts)
{
var accounts = (from a in ctx.accountSet.WhereIn(ac => ac.primarycontactid.id,contacts)
where a.name != null
select a).toArray();
}
}
There is no way you can hook into the Dynamics 365 Linq expression compiler, as far as I know, but the above code will execute in one request against the CRM, and take advantage
of the fact that you do not need to consider paging and more when working with Linq.
As you can see, there whereIn clause is added with a lambda style expression, where the rest of the query is using the Linq style.
When using QueryExpression, we can add condtionexpression for where clause. ConditionExpression takes a ConditionOperator enumerator, and we can use ConditionOperator.In. Below is how you initiate a conidtionExpression with an “In” operator, the third argument can be an array or collection.
ConditionExpression ce = new ConditionExpression("EntityName",
ConditionOperator.In, collectionObject);
Please see below for further explanation.
http://msdn.microsoft.com/en-us/library/microsoft.xrm.sdk.query.conditionexpression.conditionexpression.aspx
I do not know how to do this with Linq, as far as I know it is not possible.
It can be done with Query Expressions:
String[] productNames = new[] { "test1", "test2" };
QueryExpression products = new QueryExpression(Product.EntityLogicalName);
products.ColumnSet = new ColumnSet("name", "new_att1", "new_att2"); // fields to get
products.Criteria.AddCondition("name", ConditionOperator.In,
productNames.Cast<Object>().ToArray()); // filter by array
EntityCollection res = service.RetrieveMultiple(products);
IEnumerable<Product> opportunities = res.Entities
.Select(product => product.ToEntity<Product>()); // you can use Linq again from here
Given the name of a Migrations class as a string, how can I get the current version number as stored in Orchard_Framework_DataMigrationRecord?
I can see Version in IExtensionManager, but that appears to just be the module version as defined in module.txt.
OK, so I've solved this myself-
I knew that Orchard must already be executing similar code to what I require when it fires off migration methods, so I created a new migrations file, and put a breakpoint on the Create() method. When the breakpoint hit, I looked up through the call stack to find DataMigrationManager in Orchard.Data.Migration. Everything I needed was in there, and if anyone else has similar requirements, I suggest they have a look at that class as a starting point.
This is pretty much lifted straight out of that class:
string moduleName="Your.Module.Name";
var migrations = GetDataMigrations(moduleName);
// apply update methods to each migration class for the module
var current = 0;
foreach (var migration in migrations)
{
// copy the objet for the Linq query
var tempMigration = migration;
// get current version for this migration
var dataMigrationRecord = GetDataMigrationRecord(tempMigration);
if (dataMigrationRecord != null)
{
current = dataMigrationRecord.Version.Value;
}
// do we need to call Create() ?
if (current == 0)
{
// try to resolve a Create method
var createMethod = GetCreateMethod(migration);
if (createMethod != null)
{
//create method has been written, but not executed!
current = (int)createMethod.Invoke(migration, new object[0]);
}
}
}
Context.Output.WriteLine("Version: {0}", current);
A couple of methods you may need:
private DataMigrationRecord GetDataMigrationRecord(IDataMigration tempMigration)
{
return _dataMigrationRepository.Table
.Where(dm => dm.DataMigrationClass == tempMigration.GetType().FullName)
.FirstOrDefault();
}
private static MethodInfo GetCreateMethod(IDataMigration dataMigration)
{
var methodInfo = dataMigration.GetType().GetMethod("Create", BindingFlags.Public | BindingFlags.Instance);
if (methodInfo != null && methodInfo.ReturnType == typeof(int))
{
return methodInfo;
}
return null;
}
Don't forget to inject any dependencies that you may need.
I have a js function that is named getID which is basically return document.getElementById(id)
I want to make another function, getTag that would return getElementsByTagName.
The part that I can't seem to manage is that I want to be able to call them like this:
getID('myid').getTag('input') => so this would return all the input elements inside the element with the id myid
Thanks!
ps: getTag would also have to work if it's called by it's own, but then it would just return document.getElementsByTagName
UPDATE:
Thanks to all that have replied! Using your suggestions I came up with this, which works well for me:
function getEl(){
return new getElement();
}
function getElement() {
var scope = document;
this.by = function(data){
if (data.id) scope = scope.getElementById(data.id);
if (data.tag) scope = scope.getElementsByTagName(data.tag);
return scope;
}
}
and I use it like this:
var inputs = getEl().by({id:"msg", tag:"input"});
The way to do that is to prototype Object. To do that, you'll need the following piece of code:
Object.prototype.getTag = function(tagName) {
return this.getElementsByTagName(tagName);
}
However, this will expand all objects because what you really need to prototype, an HTMLElement, is very hard to do consistently. All the experts agree that you should never expand the Object prototype. A much better solution would be to create a function that gets the tag name from another argument:
function getTag(tagName, element) {
return (element || document).getElementsByTagName(tagName);
}
// Usage
var oneTag = getTag('input', getID('myid')); // All inputs tags from within the myid element
var twoTag = getTag('input'); // All inputs on the page
This would require that whatever is returned by getID('myid') (an HTML element) exposes a method named getTag(). This is not the case. Browsers implement the DOM specification and expose the methods defined there.
While you technically can enhance native objects with your own methods, it's best not to do it.
What you try to do has been solved rather nicely in JS libraries like jQuery already, I recommend you look at one of them before you invest time in mimicking what they can do. For example, your line of code would become:
$("#myid input")
in jQuery. jQuery happens to be the most widely used JS library around, there are many others.
Basically, you're going to create a single object that contains each of your methods and also stores all data returned by the native functions. It would look something like this (not tested, but you get the idea):
var MyLib = {
getID: function(id) {
var element = document.getElementById(id);
this.length = 1;
this[0] = element;
return this;
},
getTag: function(tag) {
var elements;
if (this.length) {
for (var i = 0; i < this.length; i++) {
var byTag = this[i].getElementsByTagName(tag);
for (var j = 0; j < byTag.length; j++) {
elements.push(byTag[j]);
}
}
}
for (var i = 0; i < elements.length; i++) {
this[i] = elements[i];
}
this.length = elements.length;
return this;
}
};
You can then use it like this:
var elements = MyLib.getID('myid').getTag('input');
for (var i = 0; i < elements.length; i++)
console.log(elements[i]); // Do something
The only real problem with this approach (besides it being very tricky and hard to debug) is that you have to treat the result of every method like an array, even if there is only a single result. For example, to get an element by ID, you'd have to do MyLib.getID('myid')[0].
However, note that this has already been done before. I recommend you take a look at jQuery, if only to see how they accomplished this. Your code could be simplified to this:
$("#myid input")
jQuery is more lightweight than you think, and including it on your page will not slow it down. You have nothing to lose by using it.
Just use the DOMElement.prototype property.
You'll get something like this :
function getTag(tagName) {
return document.getElementsByTagName(tagName);
}
DOMElement.prototype.getTag = function(tagName) {
return this.getElementsByTagName(tagName);
}
But you should use jQuery for this.
EDIT: My solution doesn't work on IE, sorry !
You could define it as follows:
var Result = function(el)
{
this.Element = el;
};
Result.prototype.getTag = function(tagName)
{
return this.Element.getElementsByTagName(tagName);
};
var getTag = function(tagName)
{
return document.getElementsByTagName(tagName);
};
var getID = function(id)
{
var el = document.getElementById(id);
return new Result(el);
};
Whereby a call to getID will return an instance of Result, you can then use its Element property to access the HTML element returned. The Result object has a method called getTag which will return all child elements matching that tag from the parent result. We then also define a seperate getTag method which calls the document element's getElementsByTagName.
Still though...JQuery is so much easier... $("#myId input");
Unless this is an academic exercise on how to chain methods in JavaScript (it doesn't seem to be, you simply seem to be learning JavaScript), all you have to do is this:
var elements = document.getElementById("someIdName");
var elementsByTag = elements.getElementsByTagName("someTagName");
for (i=0; i< elementsByTag.length; i++) {
alert('found an element');
}
If you want to define a reusable function all you have to do is this:
function myFunction(idName,tagName) {
var elements = document.getElementById(idName);
var elementsByTag = elements.getElementsByTagName(tagName);
for (i=0; i< elementsByTag.length; i++) {
alert('found a ' + tagName + ' element within element of id ' + idName);
}
}
It's true that if this is all the JavaScript functionality you need on your page, then there is no need to import jQuery.
I am building an asp.net site in .net framework 4.0, and I am stuck at the method that supposed to call a .cs class and get the query result back here is my method call and method
1: method call form aspx.cs page:
helper cls = new helper();
var query = cls.GetQuery(GroupID,emailCap);
2: Method in helper class:
public IQueryable<VariablesForIQueryble> GetQuery(int incomingGroupID, int incomingEmailCap)
{
var ctx = new some connection_Connection();
ObjectSet<Members1> members = ctx.Members11;
ObjectSet<groupMember> groupMembers = ctx.groupMembers;
var query = from m in members
join gm in groupMembers on m.MemberID equals gm.MemID
where (gm.groupID == incomingGroupID) && (m.EmailCap == incomingEmailCap)
select new VariablesForIQueryble(m.MemberID, m.MemberFirst, m.MemberLast, m.MemberEmail, m.ValidEmail, m.EmailCap);
//select new {m.MemberID, m.MemberFirst, m.MemberLast, m.MemberEmail, m.ValidEmail, m.EmailCap};
return query ;
}
I tried the above code with IEnumerable too without any luck. This is the code for class VariablesForIQueryble:
3:Class it self for taking anonymouse type and cast it to proper types:
public class VariablesForIQueryble
{
private int _emailCap;
public int EmailCap
{
get { return _emailCap; }
set { _emailCap = value; }
}`....................................
4: and a constructor:
public VariablesForIQueryble(int memberID, string memberFirst, string memberLast, string memberEmail, int? validEmail, int? emailCap)
{
this.EmailCap = (int) emailCap;
.........................
}
I can't seem to get the query result back, first it told me anonymous type problem, I made a class after reading this: link text; and now it tells me constructors with parameters not supported. Now I am an intermediate developer, is there an easy solution to this or do I have to take my query back to the .aspx.cs page.
If you want to project to a specific type .NET type like this you will need to force the query to actually happen using either .AsEnumerable() or .ToList() and then use .Select() against linq to objects.
You could leave your original anonymous type in to specify what you want back from the database, then call .ToList() on it and then .Select(...) to reproject.
You can also clean up your code somewhat by using an Entity Association between Groups and Members using a FK association in the database. Then the query becomes a much simpler:
var result = ctx.Members11.Include("Group").Where(m => m.Group.groupID == incomingGroupID && m.EmailCap == incomingEmailCap);
You still have the issue of having to do a select to specify which columns to return and then calling .ToList() to force execution before reprojecting to your new type.
Another alternative is to create a view in your database and import that as an Entity into the Entity Designer.
Used reflection to solve the problem:
A: Query, not using custom made "VariablesForIQueryble" class any more:
//Method in helper class
public IEnumerable GetQuery(int incomingGroupID, int incomingEmailCap)
{
var ctx = new some_Connection();
ObjectSet<Members1> members = ctx.Members11;
ObjectSet<groupMember> groupMembers = ctx.groupMembers;
var query = from m in members
join gm in groupMembers on m.MemberID equals gm.MemID
where ((gm.groupID == incomingGroupID) && (m.EmailCap == incomingEmailCap)) //select m;
select new { m.MemberID, m.MemberFirst, m.MemberLast, m.MemberEmail, m.ValidEmail, m.EmailCap };
//select new VariablesForIQueryble (m.MemberID, m.MemberFirst, m.MemberLast, m.MemberEmail, m.ValidEmail, m.EmailCap);
//List<object> lst = new List<object>();
//foreach (var i in query)
//{
// lst.Add(i.MemberEmail);
//}
//return lst;
//return query.Select(x => new{x.MemberEmail,x.MemberID,x.ValidEmail,x.MemberFirst,x.MemberLast}).ToList();
return query;
}
B:Code to catch objects and conversion of those objects using reflection
helper cls = new helper();
var query = cls.GetQuery(GroupID,emailCap);
if (query != null)
{
foreach (var objRow in query)
{
System.Type type = objRow.GetType();
int memberId = (int)type.GetProperty("MemberID").GetValue(objRow, null);
string memberEmail = (string)type.GetProperty("MemberEmail").GetValue(objRow, null);
}
else
{
something else....
}
I couldnt find any good example of doing this online.
Can someone please show how to run a stored procedure (that returns multiple resultsets) from groovy?
Basically I am just trying to determine how many resultsets the stored procedure returns..
I have written a helper which allows me to work with stored procedures that return a single ResultSet in a way that is similar to working with queries with groovy.sql.Sql. This could easily be adapted to process multiple ResultSets (I assume each would need it's own closure).
Usage:
Sql sql = Sql.newInstance(dataSource)
SqlHelper helper = new SqlHelper(sql);
helper.eachSprocRow('EXEC sp_my_sproc ?, ?, ?', ['a', 'b', 'c']) { row ->
println "foo=${row.foo}, bar=${row.bar}, baz=${row.baz}"
}
Code:
class SqlHelper {
private Sql sql;
SqlHelper(Sql sql) {
this.sql = sql;
}
public void eachSprocRow(String query, List parameters, Closure closure) {
sql.cacheConnection { Connection con ->
CallableStatement proc = con.prepareCall(query)
try {
parameters.eachWithIndex { param, i ->
proc.setObject(i+1, param)
}
boolean result = proc.execute()
boolean found = false
while (!found) {
if (result) {
ResultSet rs = proc.getResultSet()
ResultSetMetaData md = rs.getMetaData()
int columnCount = md.getColumnCount()
while (rs.next()) {
// use case insensitive map
Map row = new TreeMap(String.CASE_INSENSITIVE_ORDER)
for (int i = 0; i < columnCount; ++ i) {
row[md.getColumnName(i+1)] = rs.getObject(i+1)
}
closure.call(row)
}
found = true;
} else if (proc.getUpdateCount() < 0) {
throw new RuntimeException("Sproc ${query} did not return a result set")
}
result = proc.getMoreResults()
}
} finally {
proc.close()
}
}
}
}
All Java classes are usable from Groovy. If Groovy does not give you a way to do it, then you can do it Java-way using JDBC callable statements.
I just stumbled across what could possibly be a solution to your problem, if an example was what you were after, have a look at the reply to this thread