Bool query (must, should, must_not, filter) in Elasticsearch - Mini Project: Build & Apply

Bool query (must, should, must_not, filter)

📖 Scenario: You are working with an Elasticsearch index of books. Each book has fields like title, author, genre, and year. You want to find books that match certain conditions using a bool query.

🎯 Goal: Build an Elasticsearch bool query using must, should, must_not, and filter clauses to find books that meet specific criteria.

📋 What You'll Learn

Create a bool query JSON with must, should, must_not, and filter clauses

Use exact field names: title, author, genre, year

Use match queries inside must and should

Use term query inside must_not

Use range query inside filter

💡 Why This Matters

🌍 Real World

Bool queries are used in search engines to combine multiple conditions for filtering and scoring search results.

💼 Career

Knowing how to build bool queries is essential for roles involving search, data retrieval, and Elasticsearch administration.

1

Create the base bool query structure

Create a variable called bool_query and set it to a JSON object with an empty bool key containing empty lists for must, should, must_not, and filter.

Elasticsearch

bool_query = {
    "bool": {
        "must": [],
        "should": [],
        "must_not": [],
        "filter": []
    }
}
# Your code here

Need a hint?

Start by creating a dictionary named bool_query with a bool key. Inside bool, add keys must, should, must_not, and filter each set to empty lists.

2

Add a must clause with a match query

Add a match query for author with value "Agatha Christie" inside the must list of bool_query.

Elasticsearch

bool_query = {
    "bool": {
        "must": [],
        "should": [],
        "must_not": [],
        "filter": []
    }
}
# Add a match query for author 'Agatha Christie' inside must

Need a hint?

Inside the must list, add a dictionary with a match key. The value should be another dictionary with author as key and "Agatha Christie" as value.

3

Add should, must_not, and filter clauses

Add a match query for genre with value "mystery" inside the should list. Add a term query for title with value "Twilight" inside the must_not list. Add a range query for year greater than or equal to 1950 inside the filter list of bool_query.

Elasticsearch

bool_query = {
    "bool": {
        "must": [
            {"match": {"author": "Agatha Christie"}}
        ],
        "should": [],
        "must_not": [],
        "filter": []
    }
}
# Add match query for genre 'mystery' in should
# Add term query for title 'Twilight' in must_not
# Add range query for year >= 1950 in filter

Need a hint?

Remember to add one dictionary inside each list: should gets a match for genre, must_not gets a term for title, and filter gets a range for year with gte 1950.

4

Print the final bool query JSON

Print the bool_query variable to display the complete bool query JSON.

Elasticsearch

bool_query = {
    "bool": {
        "must": [
            {"match": {"author": "Agatha Christie"}}
        ],
        "should": [
            {"match": {"genre": "mystery"}}
        ],
        "must_not": [
            {"term": {"title": "Twilight"}}
        ],
        "filter": [
            {"range": {"year": {"gte": 1950}}}
        ]
    }
}
print(bool_query)
# Your code here

Need a hint?

Use print(bool_query) to show the final JSON object.