Question

Consider the following SQL functions:
(A) CURDATE()
(B) CURRENT DATE()
(C) CURRENT DATE
(D) TODAY()

• A. (A), (B), and (D) only
• B. (A), (B), and (C) only
• C. (A), (B), (C), and (D)
• D. (B), (C), and (D) only

Answer 1

The Correct Option is B

In SQL, different database management systems (DBMS) may implement date functions differently. Let's analyze the functions given: 

• (A) CURDATE(): This is a MySQL function that returns the current date in the format 'YYYY-MM-DD'. It is widely supported in MySQL.
• (B) CURRENT DATE(): This looks like a syntax error because typical SQL functions with spaces usually do not include parentheses. However, CURRENT DATE is a valid syntax in DB2, Oracle, and other SQL databases to obtain the current date.
• (C) CURRENT DATE: This is a standard SQL function present in many databases such as DB2, PostgreSQL without parentheses. It is used to retrieve the current date.
• (D) TODAY(): This is not a standard SQL function. It does not exist in major databases like MySQL, PostgreSQL, or SQL Server.

Based on the typical implementations and standards of SQL functions, options (A) and (C) are known to provide the current date. However, (B) might be perceived as incorrect due to additional parentheses which do not conform to the standard syntax, but in broad interpretation context or typo correction, one can see it matches with (C). Therefore, the correct answer includes:

• (A) CURDATE()
• (B) CURRENT DATE() (assuming it refers to CURRENT DATE without parentheses)
• (C) CURRENT DATE

Consequently, the correct choice based on the standard usage and interpretation of these functions in various DBMS is:

(A), (B), and (C) only

Answer 2

The SQL functions that return the current date are (A) CURDATE(), (B) CURRENT_DATE(), and (C) CURRENT_DATE.

Additional Context:

• Valid Date Functions:
  • CURDATE() (A): MySQL function returning current date
  • CURRENT_DATE() (B): MySQL/SQL standard function (parentheses optional)
  • CURRENT_DATE (C): SQL standard (no parentheses)
• About TODAY() (D):
  • Not a standard SQL function
  • Used in spreadsheet applications (Excel)
• Database Compatibility:
  • MySQL/MariaDB: Supports all three valid functions
  • PostgreSQL: Uses CURRENT_DATE
  • SQL Server: GETDATE() or CURRENT_TIMESTAMP
• Usage Example:

  SELECT CURDATE(), CURRENT_DATE(), CURRENT_DATE;
  -- Returns: 2023-11-15 | 2023-11-15 | 2023-11-15
      

Correct Answer: (2) (A), (B) and (C) only.