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
Structured Query Language
Simple Query Language

Explanation:

No explanation available.

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

Explanation:

No explanation available.

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

Explanation:

No explanation available.

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

Explanation:

No explanation available.

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

Explanation:

No explanation available.

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

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 row data are returned.
Both A and B are correct.
limits the column data that 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
Primary keys
Default values
N/A / Missing in source dump

Explanation:

No explanation available.

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

Explanation:

No explanation available.

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

Explanation:

No explanation available.

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

Explanation:

No explanation available.

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

Explanation:

No explanation available.

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

Explanation:

No explanation available.

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

Explanation:

No explanation available.

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

Explanation:

No explanation available.

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

Explanation:

No explanation available.

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

Explanation:

No explanation available.

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

Explanation:

No explanation available.

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

Explanation:

No explanation available.

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

Explanation:

No explanation available.

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

Explanation:

The correct option is: Option B

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

Explanation:

The correct option is: Option A

Q. Which of the following is true about PRIMARY KEY in SQL?
There can be many primary keys in a table
It allows NULL values
It uniquely identifies each record 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?
DELETE * FROM table_name;
TRUNCATE TABLE table_name;
DROP TABLE table_name;

Explanation:

The correct option is: Option B

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

Explanation:

The correct option is: Option A

Q. What does the BETWEEN operator do in SQL?
Checks if a value is within a range
Checks for exact equality
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?
HAVING
GROUP BY
ORDER BY

Explanation:

The correct option is: Option A

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

Explanation:

The correct option is: Option B

Q. What is the main purpose of an INDEX in SQL?
To speed up retrieval of rows
To remove duplicates
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 = 'NULL';
SELECT * FROM employee WHERE commission IS NULL;
SELECT * FROM employee WHERE commission = 0;

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 SORT BY department_id, salary;
SELECT * FROM employees ORDER BY department_id ASC, salary DESC;
SELECT * FROM employees ORDER BY department_id, salary;

Explanation:

The correct option is: Option A

Q. Which of the following best describes a VIEW in SQL?
A permanent copy of a table
A virtual table based on a query
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?
ONLY
UNIQUE
DISTINCT

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?
CASE
IF
SWITCH

Explanation:

The correct option is: Option B

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

Explanation:

The correct option is: Option A

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

Explanation:

The correct option is: Option B

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

Explanation:

The correct option is: Option C

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

Explanation:

The correct option is: Option A

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

Explanation:

The correct option is: Option B

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

Explanation:

The correct option is: Option A

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

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?
Only first row is deleted
Nothing happens
All rows are deleted

Explanation:

The correct option is: Option B

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

Explanation:

The correct option is: Option C

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

Explanation:

The correct option is: Option A

Q. Which SQL comparison is used to check if a value is NULL?
value = NULL
value IS 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, it includes both values
Yes, but only the lower value

Explanation:

The correct option is: Option A

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

Explanation:

The correct option is: Option C

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

Explanation:

The correct option is: Option A

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

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?
All rows are deleted
Nothing happens
Only first row is deleted

Explanation:

The correct option is: Option B

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