Consider the table structure shown by this output:
Mysql> desc city:
5 rows in set (0.00 sec)
You execute this statement:
SELECT -,-, city. * FROM city LIMIT 1
What is returned?
A.
An error message
B.
One row with 5 columns
C.
One row with 10 columns
D.
One row with 15 columns
A
If the question is correct it’s A.
But I don’t think it written correctly so I want to put my thoughts on this…
These return error messages:
SELECT -,-, city. * FROM city LIMIT 1
SELECT *,*,city.* FROM city LIMIT 1;
SELECT city.*,*,city.* FROM city LIMIT 1;
SELECT *,city.*,* FROM city LIMIT 1;
SELECT *,* FROM city LIMIT 1;
SELECT city.*,* FROM city LIMIT 1;
These returns 15
SELECT city.*,city.*,city.* FROM city LIMIT 1;
SELECT *,city.*,city.* FROM city LIMIT 1;
These Return 10
SELECT city.*,city.* FROM city LIMIT 1;
SELECT *,city.* FROM city LIMIT 1;
These return 5
SELECT city.* FROM city LIMIT 1;
SELECT * FROM city LIMIT 1;
What I am trying to say is, “If two asterisks (*,*) are used together then the statement produces an error, or if an asterisks (*) is used after the table name asterisk(city.*) it also produces an error.
So I believe the question is asking (SELECT *,*, city.* FROM city LIMIT 1) which produces an error.
<3
A
A