Difference between revisions of "Delete Queries"

From TRCCompSci - AQA Computer Science
Jump to: navigation, search
(Basic Quiz)
(Basic Quiz)
Line 23: Line 23:
 
<quiz display=simple>
 
<quiz display=simple>
  
{which of the following delete the record for 'Wonder Woman':
+
{which of the following will successfully delete the record for 'Wonder Woman':
  
  
Line 29: Line 29:
 
+ Delete From Employees Where 'First Name' = 'Wonder' And 'Last Name' = 'Woman'
 
+ Delete From Employees Where 'First Name' = 'Wonder' And 'Last Name' = 'Woman'
 
||Correct
 
||Correct
- Insert Into Employees ('First Name', 'Last Name', 'Address', 'City', 'Age') Data ('Joe', 'Bloggs', '1 Some Street', 'Sheffield', 35)
+
- Delete From Employees Where 'First Name' = 'Wonder' , 'Last Name' = 'Woman'
 
||Incorrect
 
||Incorrect
- Insert Into Employees ('First Name', 'Last Name', 'Address', 'Age', 'City') Data ('Joe', 'Bloggs', '1 Some Street', 'Sheffield', 35)
+
- Delete From Employees Where 'Name' = 'Wonder Woman'
 
||Incorrect
 
||Incorrect
- Insert Into Employees ('First Name', 'Last Name', 'Address', 'Age', 'City') Values ('Joe', 'Bloggs', '1 Some Street', 'Sheffield', 35)
+
- Delete From Employees Where 'Last Name' = 'Woman'
 
||Incorrect
 
||Incorrect
  
 
</quiz>
 
</quiz>

Revision as of 11:35, 28 September 2020

Used for deleting rows from a table. The where section should give the criteria for deleting records, for example the specific ID for the record could be used. Alternatively the criteria could be more complex and use multiple criteria.

   DELETE FROM table WHERE column1=value1;

or:

   DELETE FROM table WHERE column1=value1 AND column2=value2;

Notes

  • Not specifying which records to delete will result in every record being deleted
  • The same can be achieved with 'DELETED * FROM table'
  • This process cannot be undone
  • Not to be confused with DROP, for deleting columns and tables.

Basic Quiz

All these questions will use this table called Employees:

Capture.png

1. which of the following will successfully delete the record for 'Wonder Woman':

Delete From Employees Where 'First Name' = 'Wonder' And 'Last Name' = 'Woman'
Correct
Delete From Employees Where 'First Name' = 'Wonder' , 'Last Name' = 'Woman'
Incorrect
Delete From Employees Where 'Name' = 'Wonder Woman'
Incorrect
Delete From Employees Where 'Last Name' = 'Woman'
Incorrect

Your score is 0 / 0