QueryByAttribute Vs QueryExpression in MS Dynamics CRM

08MAY2017

Difference between QueryByAttribute and QueryExpression

posted in QueryExpressions

QueryByAttribute and QueryExpression are classes to query the data from CRM. Below are some of the differences we have:

QueryByAttribute:

• QueryByAttribute class is a simple class compared to QueryExpression class. Hence, we can select QueryByAttribute if the query is simple.
• No need to enter the conditions expression, condition operators while designing the criteria for QueryByAttribute.
• It queries the CRM data from specified entity by specifying criteria with set of attributes and value pairs.
• It automatically consider “AND” between specified attributes as it doesn’t support “OR”.
• It supports only “Equal” condition operator.

Example:

It retrieves all the accounts which are related to country India and state Delhi.

QueryByAttribute accQueryByAttr = new QueryByAttribute(“account”);

 accQueryByAttr.ColumnSet = new ColumnSet(true);

accQueryByAttr.Attributes.AddRange(“new_country”, “new_state”);

accQueryByAttr.Values.AddRange(“India”, “Delhi”);

QueryExpression

• QueryExpression is an object oriented, strongly typed approach to developing queries against the CRM database.
• We need to specify the conditionExpression and Conditiion Operators while designing the queries.
• QueryExpression is preferable if we want to query the CRM data with complex conditions.
• It supports the complex conditions with “AND” and “OR” operators
• It supports different condition operators like “Beginswith, Doesn’tbeginwith, Endswith,…”
• It supports to retrieve the data based on Link entities.

Example: Below query retrieves all the accounts their names starts with “CRM” and related to India country.

QueryExpression accQueryExp = new QueryExpression(“account”);

 accQueryExp.ColumnSet = new ColumnSet(true);

accQueryExp.Criteria.AddCondition(“name”, ConditionOperator.BeginsWith, “CRM”);

accQueryExp.Criteria.AddCondition(“new_country”, ConditionOperator.Equal, “India”);

EntityCollection retrievedAccounts=(EntityCollection)OPCrmService.RetrieveMultiple(accQueryExp);

C# code to Check Whether the User is Part of a Team in MS CRM 2011 using QueryExpression

posted in ms crm 2011, queryexpressions

C# code to Check Whether the User is Part of a Team in MS CRM 2011 using QueryExpression

 QueryExpression teamQuery = new QueryExpression(“team”);

ColumnSet teamColumnSet = new ColumnSet(“name”);

teamQuery.ColumnSet = teamColumnSet;
teamQuery.Criteria = new FilterExpression();
teamQuery.Criteria.FilterOperator = LogicalOperator.And;
teamQuery.Criteria.AddCondition(“name”, ConditionOperator.Equal, “<Team Name>”);
teamQuery.AddLink(“teammembership”, “teamid”, “teamid”).AddLink(“systemuser”, “systemuserid”, “systemuserid”).LinkCriteria.AddCondition(“systemuserid”, ConditionOperator.Equal, context.UserId);