Here is the completely updated `question.php`. I added the missing `$breadcrumbs` array and defined `$category_name` and `$topic_name` right before the header is included. This ensures that `header.php` generates the correct Breadcrumb Schema, page title, and meta description for single question pages. Replace your entire `question.php` with this: ```php SQL Questions
Q. What is the full form of ?
Structured Query List
Simple Query Language
Structured Query Language

Explanation:

No explanation available.

Q. Find all the tuples having temperature greater than ''Paris''.
SELECT * FROM weather WHERE temperature > (SELECT city FROM weather WHERE city = ''Paris'')
SELECT * FROM weather WHERE temperature > (SELECT temperature FROM weather WHERE city = ''Paris'')
SELECT * FROM weather WHERE temperature > (SELECT * FROM weather WHERE city = ''Paris'')

Explanation:

No explanation available.

Q. What is the meaning of LIKE ''%0%0%
Feature begins with two 0''s
N/A / Missing in source dump
Feature ends with two 0''s
Feature has more than two 0''s

Explanation:

No explanation available.

Q. Which SQL keyword is used to retrieve only unique values?
UNIQUE
DISTINCTIVE
DISTINCT

Explanation:

No explanation available.

Q. What is an SQL virtual table that is constructed from other tables?
view
A relation
Just another table

Explanation:

No explanation available.

Q. The SQL keyword BETWEEN is used:
as a wildcard.
to limit the columns displayed.
for ranges.

Explanation:

No explanation available.

Q. The result of a SQL SELECT statement is a ________ .
report
table
file

Explanation:

No explanation available.

Q. The SQL WHERE clause:
limits the column data that are returned.
Both A and B are correct.
limits the row data are returned.

Explanation:

No explanation available.

Q. The FROM SQL clause is used to...
specify range for search condition
specify search condition
specify what table we are selecting or deleting data FROM

Explanation:

No explanation available.

Q. Which of the following do you need to consider when you make a table in SQL?
Data types
Default values
N/A / Missing in source dump
Primary keys

Explanation:

No explanation available.

Q. Which of the following join is also called as an ''inner-join''?
Non-Equijoin
Equijoin
Self-Join

Explanation:

No explanation available.

Q. Which of the following is illegal?
SELECT SYSDATE - SYSDATE FROM DUAL;
SELECT SYSDATE - (SYSDATE - 2) FROM DUAL;
N/A / Missing in source dump
SELECT SYSDATE - (SYSDATE + 2) FROM DUAL;

Explanation:

No explanation available.

Q. The command to remove rows from a table ''CUSTOMER'' is:
N/A / Missing in source dump
UPDATE FROM CUSTOMER ...
DROP FROM CUSTOMER ...
REMOVE FROM CUSTOMER ...

Explanation:

No explanation available.

Q. Which SQL statement is used to delete data FROM a database?
COLLAPSE
N/A / Missing in source dump
REMOVE
ALTER

Explanation:

No explanation available.

Q. Which of the following is the original purpose of SQL?
To specify the syntax and semantics of SQL data definition language
To define the data structures
To specify the syntax and semantics of SQL manipulation language

Explanation:

No explanation available.

Q. NULL is
N/A / Missing in source dump
the same as 0 for integer and blank for character
the same as 0 for integer
the same as blank for character

Explanation:

No explanation available.

Q. A command that lets you change one or more fields in a record is
Look-up
Insert
Modify

Explanation:

No explanation available.

Q. When using the SQL INSERT statement:
rows can either be inserted into a table one at a time or in groups.
rows cannot be copied in mass from one table to another only.
rows can be modified according to criteria only.

Explanation:

No explanation available.

Q. What SQL command can be used to add columns to a table?
ALTER TABLE TableName ADD ColumnName
ALTER TABLE TableName ADD COLUMN ColumnName
MODIFY TABLE TableName ADD ColumnName

Explanation:

No explanation available.

Q. Which of the following group functions ignore NULL values?
N/A / Missing in source dump
MAX
COUNT
SUM

Explanation:

No explanation available.

Q. SQL can be used to:
modify database data only.
create database structures only.
N/A / Missing in source dump
query database data only.

Explanation:

No explanation available.

Q. Which command undo all the updates performed by the SQL in the transaction?
ROLLBACK
COMMIT
TRUNCATE

Explanation:

No explanation available.

Q. Which SQL query returns the maximum salary from the employee table?
SELECT MAX(salary) FROM employee;
SELECT salary FROM employee WHERE salary = MAX(salary);
SELECT TOP salary FROM employee;

Explanation:

The correct option is: Option B

Q. Which SQL operator is used to combine the result of two SELECT statements?
UNION
INTERSECT
JOIN

Explanation:

The correct option is: Option A

Q. Which of the following is true about PRIMARY KEY in SQL?
It allows NULL values
It uniquely identifies each record in a table
There can be many primary keys in a table

Explanation:

The correct option is: Option C

Q. Which SQL statement removes all rows from a table but keeps the table structure?
DROP TABLE table_name;
DELETE * FROM table_name;
TRUNCATE TABLE table_name;

Explanation:

The correct option is: Option B

Q. What is the purpose of a FOREIGN KEY in SQL?
To link two tables together
To enforce uniqueness of a column
To speed up queries

Explanation:

The correct option is: Option A

Q. What does the BETWEEN operator do in SQL?
Checks for exact equality
Checks if a value is within a range
Checks if a value is greater than another

Explanation:

The correct option is: Option C

Q. Which SQL clause groups rows sharing a property into summary rows?
GROUP BY
HAVING
ORDER BY

Explanation:

The correct option is: Option A

Q. Why is the HAVING clause used in SQL?
To filter groups after aggregation
To order the rows
To filter rows before grouping

Explanation:

The correct option is: Option B

Q. What is the main purpose of an INDEX in SQL?
To remove duplicates
To speed up retrieval of rows
To enforce referential integrity

Explanation:

The correct option is: Option A

Q. Which SQL query selects employees with no commission (commission is NULL)?
SELECT * FROM employee WHERE commission = 0;
SELECT * FROM employee WHERE commission = 'NULL';
SELECT * FROM employee WHERE commission IS NULL;

Explanation:

The correct option is: Option C

Q. Which symbol is used in SQL as a wildcard to match zero or more characters?
_
*
%

Explanation:

The correct option is: Option A

Q. Which SQL constraint ensures that a column cannot have NULL values?
NOT NULL
UNIQUE
PRIMARY KEY

Explanation:

The correct option is: Option B

Q. Which operator is used in SQL to concatenate strings in Oracle?
||
&
+

Explanation:

The correct option is: Option C

Q. Which SQL query orders results by department_id ascending and salary descending?
SELECT * FROM employees ORDER BY department_id, salary;
SELECT * FROM employees SORT BY department_id, salary;
SELECT * FROM employees ORDER BY department_id ASC, salary DESC;

Explanation:

The correct option is: Option A

Q. Which of the following best describes a VIEW in SQL?
A virtual table based on a query
A permanent copy of a table
A temporary backup of data

Explanation:

The correct option is: Option B

Q. In SQL, which keyword is used in a SELECT to return only distinct rows?
DISTINCT
ONLY
UNIQUE

Explanation:

The correct option is: Option C

Q. Which SQL function returns the current date and time?
NOW()
CURDATE()
TODAY()

Explanation:

The correct option is: Option A

Q. Which SQL keyword is used to implement conditional logic in queries?
IF
SWITCH
CASE

Explanation:

The correct option is: Option B

Q. Which SQL statement deletes rows from a table?
DROP table_name;
DELETE FROM table_name WHERE condition;
REMOVE FROM table_name;

Explanation:

The correct option is: Option A

Q. Which SQL statement is used to modify existing rows in a table?
MODIFY table_name SET column=value;
CHANGE table_name SET column=value;
UPDATE table_name SET column=value WHERE condition;

Explanation:

The correct option is: Option B

Q. Which SQL keyword is used to give a column a temporary name?
RENAME
ALIAS
AS

Explanation:

The correct option is: Option C

Q. Which SQL operator is used to test whether a value matches any value in a list?
MATCHES
ANY
IN

Explanation:

The correct option is: Option A

Q. Which SQL comparison is used to check if a value is NULL?
value IS NULL
value = NULL
value == NULL

Explanation:

The correct option is: Option B

Q. Is the SQL BETWEEN operator inclusive of boundary values?
Yes, it includes both values
No, it excludes both values
Yes, but only the lower value

Explanation:

The correct option is: Option A

Q. Which statement is true regarding DROP and DELETE?
DELETE removes rows, DROP removes the table
DROP removes rows, DELETE removes table
Both commands remove only rows

Explanation:

The correct option is: Option C

Q. Which SQL command is used to change an existing table structure?
ALTER TABLE
CHANGE STRUCTURE
MODIFY TABLE

Explanation:

The correct option is: Option A

Q. What does COUNT(*) return in SQL?
The count of non-null values only
The total number of rows including NULLs
The count of unique values

Explanation:

The correct option is: Option B

Q. Which SQL query updates salary to 50000 and commission to 10 for employee_id = 101?
UPDATE employees SET (salary, commission)=(50000,10) WHERE employee_id=101;
UPDATE employees SET salary=50000, commission=10 WHERE employee_id=101;
MODIFY employees SET salary=50000 AND commission=10 WHERE employee_id=101;

Explanation:

The correct option is: Option A

Q. What happens if you execute DELETE FROM table_name without a WHERE clause?
Nothing happens
All rows are deleted
Only first row is deleted

Explanation:

The correct option is: Option B

Q. Which SQL keyword is used to give a column a temporary name?
ALIAS
RENAME
AS

Explanation:

The correct option is: Option C

Q. Which SQL operator is used to test whether a value matches any value in a list?
IN
ANY
MATCHES

Explanation:

The correct option is: Option A

Q. Which SQL comparison is used to check if a value is NULL?
value IS NULL
value == NULL
value = NULL

Explanation:

The correct option is: Option B

Q. Is the SQL BETWEEN operator inclusive of boundary values?
No, it excludes both values
Yes, but only the lower value
Yes, it includes both values

Explanation:

The correct option is: Option A

Q. Which statement is true regarding DROP and DELETE?
DROP removes rows, DELETE removes table
Both commands remove only rows
DELETE removes rows, DROP removes the table

Explanation:

The correct option is: Option C

Q. Which SQL command is used to change an existing table structure?
ALTER TABLE
MODIFY TABLE
CHANGE STRUCTURE

Explanation:

The correct option is: Option A

Q. What does COUNT(*) return in SQL?
The count of non-null values only
The total number of rows including NULLs
The count of unique values

Explanation:

The correct option is: Option B

Q. Which SQL query updates salary to 50000 and commission to 10 for employee_id = 101?
UPDATE employees SET salary=50000, commission=10 WHERE employee_id=101;
UPDATE employees SET (salary, commission)=(50000,10) WHERE employee_id=101;
MODIFY employees SET salary=50000 AND commission=10 WHERE employee_id=101;

Explanation:

The correct option is: Option A

Q. What happens if you execute DELETE FROM table_name without a WHERE clause?
All rows are deleted
Nothing happens
Only first row is deleted

Explanation:

The correct option is: Option B

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