SOQL Statements

SOQL statements estimate to a list of sales force Objects, a single sObject, or an Integer for count method queries. For example, we can get details of Account named as ‘Acme’.

SOQL: List accObject = [select id, name from account where name = 'Acme'];

From this list, you can access individual elements.

Code:

if (!accObject.isEmpty()) {

// Execute commands

}

Description:

As above code checks the list of Account object contains value. Following example of code creates a new contact for the first account with the number of employees greater than 10:

Code:

Contact c = new Contact (account = [select name, address from account where NumberofEmployees > 5 limit 1]);

c.FirstName = 'Raees';

c.LastName = 'Ahmed';

insert c;

Description:

Above code inserting contacts where account of employee greater than 5 and limit is 1.

Working with SOQL Aggregate Functions

Aggregate functions in SOQL as same as in SQL, such as SUM () and MAX (), allow you to roll up and summarize your data in the query.

SOQL:

AggregateResult[] groupResult = [SELECT AVG(Amount)aver FROM Opportunity];

Object avgAmount = groupedResults[0].get('aver');

Description:

Note that any query that includes the aggregate function returns its results in an array of AggregateResult objects. AggregateResult is a read-only sObject and the only used for query results.

The following example demonstrates a SOQL query for loop used to mass update records. Suppose you want to change last name of contact across all records of contact:

Code:

public void masUpdate() {

for (List contacts:[Select FirstName, LastName From Contact]) {

if (contacts.FirstName == 'ryan' && contacts.LastName == 'ander') {

contacts.LastName = 'raees';

}//end of if

} //end for

update contacts; //update contact

} // end of class