SQL क्वेरी बिल्डर

The builder pattern एक जटिल object को step by step बनाता है और अंत में final result देता है, ताकि callers parts को किसी भी order में set कर सकें.

Each part is a keyword, a space, and its text:

• select <columns>: comma-separated column names (spaces around commas may vary). Optional; the default is *.
• from <table>: required.
• where <condition>, order <columns>, limit <n>: optional.

If a keyword appears more than once, the last one wins. Query को इस fixed order में, single spaces के साथ बनाएं:

SELECT <columns> FROM <table>[ WHERE <condition>][ ORDER BY <columns>][ LIMIT <n>]

In the SELECT list, प्रत्येक column को trim करें और उन्हें , के साथ join करें. All other texts are copied unchanged.

Implement query_builder(parts).

Input

parts: The parts, in any order.

Output

Return the SQL query string.

सीमाएँ

1 ≤ हिस्सों की संख्या ≤ 20

कम से कम एक from हिस्सा; हर हिस्से में अधिकतम 100 कैरेक्टर

उदाहरण

इनपुट:
parts = ["where age \u003e 18", "from users", "select name,age"]

अपेक्षित आउटपुट:
expected = "SELECT name, age FROM users WHERE age \u003e 18"

इनपुट:
std::vector<std::string> parts = {"where age \u003e 18", "from users", "select name,age"};

अपेक्षित आउटपुट:
std::string expected = "SELECT name, age FROM users WHERE age \u003e 18";

इनपुट:
string[] parts = new string[] {"where age \u003e 18", "from users", "select name,age"};

अपेक्षित आउटपुट:
string expected = "SELECT name, age FROM users WHERE age \u003e 18";

इनपुट:
parts = ["from orders", "limit 10", "order total DESC"]

अपेक्षित आउटपुट:
expected = "SELECT * FROM orders ORDER BY total DESC LIMIT 10"

इनपुट:
std::vector<std::string> parts = {"from orders", "limit 10", "order total DESC"};

अपेक्षित आउटपुट:
std::string expected = "SELECT * FROM orders ORDER BY total DESC LIMIT 10";

इनपुट:
string[] parts = new string[] {"from orders", "limit 10", "order total DESC"};

अपेक्षित आउटपुट:
string expected = "SELECT * FROM orders ORDER BY total DESC LIMIT 10";

संदर्भ

यह चुनौती CodeUtility के लिए अनुकूलित की गई है। ऊपर दिए गए स्टेटमेंट और सीमाओं का पालन करें।

• Refactoring.Guru, Design Patterns
• Gamma, Helm, Johnson, Vlissides, Design Patterns: Elements of Reusable Object-Oriented Software