Examining the execution of SELECT statements in Oracle SQL requires understanding correct syntax, especially regarding aliases and string literals:
* Option A: Incorrect. Although the syntax might seem plausible, using DATE as an alias without quotes can lead to ambiguity because DATE is a reserved keyword in Oracle SQL. This might cause an error or unexpected behavior unless it is enclosed in double quotes.
* Option B: Incorrect. Single quotes are used for string literals in SQL, not for aliasing column names.
Using single quotes for aliasing, as in 'CUSTOMER-ID', 'DUES', is syntactically incorrect and will result in an error.
* Option C: Correct. This statement uses valid syntax with no reserved keywords as aliases and no misuse of string literal notation. Aliases are provided without quotes, which is acceptable as long as they are not
* reserved words or contain special characters.
* Option D: Correct. It correctly uses double quotes for aliasing, which is necessary when using reserved words like "DATE" or special characters. This is a proper use of SQL syntax for aliasing in Oracle.
* Option E: Incorrect. This statement attempts to use aliases with hyphens without enclosing them in double quotes, which leads to syntax errors. Also, customer id seems to be missing an underscore or another connector to properly reference a column name, indicating a typo or error.
For these queries, ensuring correct alias syntax and avoiding reserved keywords without appropriate quoting are key elements for successful execution.