What is the difference between Count() And Count(fieldname) In Salesforce SOQL?

Hi Anurag,

COUNT(): It is an optional clause that can be used in a SELECT statement in a SOQL query to discover the number of rows that a query returns.This function returns the number of rows that match the filtering conditions and COUNT() must be the only element in the select list. The resulting query result size field which returns the number of rows and the records will return null.In simple words, COUNT() returns the number of items in a group, including NULL values and duplicates.

COUNT(fieldname) :This function returns the number of rows that match the filtering conditions and have a non-null value records. An Aggregate Result object in the records field contains the number of rows. Do not use the size field for the resulting records.

Again in simple words, COUNT(expression) evaluates an expression for each row in a group and returns the number of non-null values.

Hi,

COUNT() is an older SOQL function that was available prior to other aggregate functions. It returns an integer. If you use COUNT(fieldName) the result of the query will be a List instead.

COUNT() is equivalent to COUNT(*) in SQL. It return the total row count. COUNT(fieldName) only counts the number of non-null records. If you want to use COUNT(fieldName), the following code should work:

List<AggregateResult> result  = [select count(Id) total from Account];

System.debug(result[0].get('total'));

Thanks