SOQL
– SOQL (Salesforce object Query Language) retrieves the records from the database by using “SELECT” keyword.
– By using SOQL, we can know in which object or fields the data resides.
– We can retrieve the data from single object or from multiple objects that are related to each other.
– SOQL uses the SELECT statement combined with filtering statements to return sets of data, which may optionally be ordered:
SELECT one or more fields
FROM an object
WHERE filter statements and, optionally, results are ordered
SOQL query is enclosed between square brackets. The following query retrieves a record from database that has the name field value equal to “Airway”.
Account a = [Select ID, Name from Account where Name=’acc1′];
In the above query “a” variable stores the ID, Name of the all accounts with name “acc1”
– SOQL statements evaluate to a list of SObject records, single SObject records or an integer for count method quires.
Querying Single SObject records: Below query gets single account record with given ID.
Account a = [Select Name from Account where ID=’XXXXXXXXXXXX’];
Querying List of Sobjects records: Following example is to display list of account.
// querying list of records and stores in list variable “acc”
List<Account> acc = [Select Name from Account where industry = ‘education’];
System.debug(‘Size: ‘+acc.size()); // displays size of the list
for(Integer i=0; i<=acc.size();i++)
{
System.debug(‘Size: ‘+acc[i].Name); // To display accounts stored in “acc”
}
Below query gets number of record in an object.
Integer i = [Select count() from Account where industry=’education’];
System.debug(‘Count: ‘ + i);