DOC: No example of usage implementation is provided for the langchain.chains.query_constructor.base.load_query_constructor_runnable function

[moneebullah25]

Checklist

• I added a very descriptive title to this issue.
• I included a link to the documentation page I am referring to (if applicable).

Issue with current documentation:

Description:

Currently, the load_query_constructor_runnable function documentation lacks doesn't have usage examples or scenarios, making it challenging for developers to understand.

URL to the documentation: https://api.python.langchain.com/en/latest/chains/langchain.chains.query_constructor.base.load_query_constructor_runnable.html#langchain.chains.query_constructor.base.load_query_constructor_runnable

Idea or request for content:

I tried running the function and below is the complete code and output:

from langchain.chains.query_constructor.base import load_query_constructor_runnable
from langchain.chains.query_constructor.schema import AttributeInfo
from langchain_openai import ChatOpenAI
from langchain.chains.query_constructor.ir import (
    Comparator,
    Comparison,
    Operation,
    Operator,
    StructuredQuery,
)

# Define your document contents and attribute information
document_contents = """
product_name: Widget, price: $20
product_name: Gadget, price: $35
product_name: Gizmo, price: $50
"""

attribute_info: AttributeInfo = [
    {"name": "product_name", "type": "string"},
    {"name": "price", "type": "number"},
]

model = ChatOpenAI(model="gpt-3.5-turbo", temperature=0.5)

# Create a runnable for constructing queries
runnable = load_query_constructor_runnable(
    llm=model,
    document_contents=document_contents,
    attribute_info=attribute_info,
    allowed_comparators=[Comparator.EQ, Comparator.LT, Comparator.GT],
    allowed_operators=[Operator.AND, Operator.NOT, Operator.OR],
    enable_limit=True,
    schema_prompt="Describe the query schema using allowed comparators and operators.",
    fix_invalid=True,
)

# Now you can use the runnable to construct queries based on user input
user_input = "Show me products with price less than 30"
query = runnable.middle[0].invoke(user_input).content
print(f"Constructed query: {query}")

Output:

Constructed query: 1. Wireless Bluetooth Earbuds - $29.99
2. Portable Phone Charger - $24.99
3. Travel Makeup Bag - $19.99
4. Insulated Water Bottle - $15.99
5. LED Desk Lamp - $27.99
6. Resistance Bands Set - $12.99
7. Stainless Steel Mixing Bowls - $19.99
8. Yoga Mat - $24.99
9. Essential Oil Diffuser - $28.99
10. Electric Handheld Milk Frother - $14.99

However the output is wrong and is not providing the references to the original documents provided. Needed usage implementation.