Salesforce – How can I get the code coverage of a class / org?

To get code coverage of a class or all classes you can use Tooling API on objects like:

• ApexCodeCoverage – contains coverage per class per test class
• ApexCodeCoverageAggregate – contains coverage per class for all test classes
• ApexOrgWideCoverage – contains coverage overall for all classes in the org

The best way is run queries using Developer Console

1. How many lines are covered for a specific class or trigger:

SELECT NumLinesCovered, NumLinesUncovered 
FROM ApexCodeCoverage

or

SELECT ApexClassOrTrigger.Name, NumLinesCovered, NumLinesUncovered 
FROM ApexCodeCoverageAggregate 
WHERE ApexClassOrTrigger.Name = 'SampleClassName'

2. Which lines are covered for a specific class or trigger:

SELECT Coverage 
FROM ApexCodeCoverage

or

SELECT Coverage 
FROM ApexCodeCoverage 
WHERE ApexClassOrTriggerId = 'class-id';

3. The current org-wide coverage:

SELECT PercentCovered 
FROM ApexOrgWideCoverage

4. How many lines are covered for a specific class or trigger:

SELECT NumLinesCovered, NumLinesUncovered 
FROM ApexCodeCoverage 
WHERE ApexClassOrTriggerId = 'ClassID'

5. Other usefull queries:

SELECT ApexClassOrTriggerId, ApexClassOrTrigger.Name, NumLinesCovered, NumLinesUncovered 
FROM ApexCodeCoverageAggregate 
WHERE ApexClassOrTriggerId != NULL AND ApexClassOrTrigger.Name != NULL 
AND (NumLinesCovered > 0 OR NumLinesUncovered > 0) AND NumLinesCovered != NULL 
AND NumLinesUncovered != NULL ORDER BY ApexClassOrTrigger.Name

SELECT ApexClassOrTriggerId, ApexClassOrTrigger.Name, NumLinesCovered, NumLinesUncovered 
FROM ApexCodeCoverageAggregate 
ORDER BY ApexClassOrTrigger.Name