-- Database schema
| Question : questiontext [ TEXT ] , questionid [ INTEGER ] primary_key | Survey : SurveyID [ INTEGER ] primary_key , Description [ TEXT ] | Answer : AnswerText [ TEXT ] , SurveyID [ INTEGER ] , UserID [ INTEGER ] , QuestionID [ INTEGER ] |
-- -- How many users answered "No" to question 19?

SELECT COUNT(QuestionID) FROM Answer WHERE QuestionID = 19 AND AnswerText LIKE 'No';