Podcast
Questions and Answers
Meaning of null
Meaning of null
- Unknown value
- Unavailable value
- Not applicable attribute
- All of the above (correct)
Each individual NULL value considered to be the same from every other NULL value
Each individual NULL value considered to be the same from every other NULL value
- True
- False (correct)
Null = null comparison is acceptable
Null = null comparison is acceptable
- True
- False (correct)
SQL allows queries that check whether an attribute value is null like?
SQL allows queries that check whether an attribute value is null like?
Complete select from where blocks within where clause of another query
Complete select from where blocks within where clause of another query
Compares a value with a set or multi set of values, evaluate if the value is one of the elements in the set
Compares a value with a set or multi set of values, evaluate if the value is one of the elements in the set
اذا ابي اطبق شرط على اكثر من اتربيوت اخليهم بقوس ، هذا وش يسمى؟
اذا ابي اطبق شرط على اكثر من اتربيوت اخليهم بقوس ، هذا وش يسمى؟
فيه مثال بالملخص عقب التيوبلز ارجعي شوفيه
فيه مثال بالملخص عقب التيوبلز ارجعي شوفيه
Any sum and all are used with
Any sum and all are used with
Evaluated once for each tuple in the outer query
Evaluated once for each tuple in the outer query
Queries with IN or = can be collabsed into one single block
Queries with IN or = can be collabsed into one single block
Check whether the results of a corrleated nested query is empty or not
Check whether the results of a corrleated nested query is empty or not
Natural/ outer are types of
Natural/ outer are types of
نوع من الجوين يشترط الجوين كوندشن (تحط الاتربيوتس الي لازم يتساوون) ومايشترط تشابه اسماء الاتربيوتس
نوع من الجوين يشترط الجوين كوندشن (تحط الاتربيوتس الي لازم يتساوون) ومايشترط تشابه اسماء الاتربيوتس
Natural join :
Natural join :
