Bool query (must, should, must_not, filter) in Elasticsearch - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to add a must clause that matches documents where the field status is active.

Elasticsearch

{
  "query": {
    "bool": {
      "must": [
        { "term": { "status": "[1]" } }
      ]
    }
  }
}

Drag options to blanks, or click blank then click option'

Aactive

Binactive

Cpending

Ddeleted

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing a status value other than 'active' will not match the requirement.

The must clause requires documents to have status equal to active.

2fill in blank

medium

Complete the code to add a should clause that boosts documents with category equal to electronics.

Elasticsearch

{
  "query": {
    "bool": {
      "should": [
        { "term": { "category": "[1]" } }
      ]
    }
  }
}

Drag options to blanks, or click blank then click option'

Aelectronics

Bclothing

Cbooks

Dfurniture

Attempts:

3 left

💡 Hint

Common Mistakes

Selecting a category other than 'electronics' will not boost the right documents.

The should clause boosts documents with category equal to electronics, making them more relevant.

3fill in blank

hard

Fix the error in the must_not clause to exclude documents with status equal to archived.

Elasticsearch

{
  "query": {
    "bool": {
      "must_not": [
        { "term": { "status": "[1]" } }
      ]
    }
  }
}

Drag options to blanks, or click blank then click option'

Aactive

Bpending

Carchived

Ddeleted

Attempts:

3 left

💡 Hint

Common Mistakes

Using a status other than 'archived' will not exclude the correct documents.

The must_not clause excludes documents where status is archived.

4fill in blank

hard

Fill both blanks to create a filter clause that filters documents with price greater than 100 and less than 500.

Elasticsearch

{
  "query": {
    "bool": {
      "filter": [
        { "range": { "price": { "gt": [1], "lt": [2] } } }
      ]
    }
  }
}

Drag options to blanks, or click blank then click option'

A100

B50

C500

D1000

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping the values or using incorrect numbers will filter wrong documents.

The filter clause restricts documents to those with price greater than 100 and less than 500.

5fill in blank

hard

Fill all three blanks to build a bool query with must matching brand 'nike', should matching color 'red', and must_not matching size 'small'.

Elasticsearch

{
  "query": {
    "bool": {
      "must": [
        { "term": { "brand": "[1]" } }
      ],
      "should": [
        { "term": { "color": "[2]" } }
      ],
      "must_not": [
        { "term": { "size": "[3]" } }
      ]
    }
  }
}

Drag options to blanks, or click blank then click option'

Anike

Bred

Csmall

Dblue

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up the values for each clause will cause incorrect filtering.

This bool query requires documents with brand 'nike', boosts those with color 'red', and excludes those with size 'small'.

Practice

1. Which clause in an Elasticsearch bool query is used to exclude documents that match a condition?

easy

A. must

B. must_not

C. should

D. filter

Solution

1. Step 1: Understand bool query clauses

   The bool query has four main clauses: must (required), should (optional), must_not (exclude), and filter (limit without scoring).

2. Step 2: Identify exclusion clause

   The must_not clause excludes documents that match its conditions from the results.

3. Final Answer:

   must_not -> Option B

4. Quick Check:

   Exclude = must_not [OK]

Hint: Exclude with must_not clause in bool query [OK]

Common Mistakes:

• Confusing must_not with must
• Using should to exclude documents
• Thinking filter excludes documents

2. Which of the following is the correct syntax to add a must clause inside a bool query in Elasticsearch?

easy

A. "bool": { "must": [ { "match": { "field": "value" } } ] }

B. "bool": { "must": ( { "match": { "field": "value" } } ) }

C. "bool": { "must": "match": { "field": "value" } }

D. "bool": { "must": { "match": { "field": "value" } } }

Solution

1. Step 1: Recall bool must clause syntax

   The must clause expects an array of query objects inside the bool query.

2. Step 2: Check each option's syntax

   "bool": { "must": [ { "match": { "field": "value" } } ] } correctly uses an array with one match query object. The other options use incorrect types or missing brackets.

3. Final Answer:

   "bool": { "must": [ { "match": { "field": "value" } } ] } -> Option A

4. Quick Check:

   Must clause = array of queries [OK]

Hint: Must clause requires an array of query objects [OK]

Common Mistakes:

• Using object instead of array for must
• Missing brackets around match query
• Using parentheses instead of brackets

3. Given this bool query snippet, which documents will be matched?

{
  "bool": {
    "must": [{ "term": { "status": "active" }}],
    "should": [{ "term": { "role": "admin" }}],
    "must_not": [{ "term": { "banned": true }}]
  }
}

medium

A. Documents with status 'active' and role 'admin', excluding banned ones

B. Documents with status 'active' or role 'admin', including banned ones

C. Documents with role 'admin' only, excluding banned ones

D. Documents with status 'active', optionally role 'admin', excluding banned ones

Solution

1. Step 1: Analyze must clause effect

   The must clause requires documents to have status: active.

2. Step 2: Analyze should and must_not clauses

   The should clause means documents with role: admin are preferred but not required. The must_not clause excludes documents where banned is true.

3. Final Answer:

   Documents with status 'active', optionally role 'admin', excluding banned ones -> Option D

4. Quick Check:

   Must + optional should + exclude must_not = Documents with status 'active', optionally role 'admin', excluding banned ones [OK]

Hint: Must is required, should is optional, must_not excludes [OK]

Common Mistakes:

• Thinking should is required
• Ignoring must_not exclusion
• Confusing must and should roles

4. Identify the error in this bool query:

{
  "bool": {
    "must": { "match": { "title": "Elasticsearch" } },
    "filter": { "term": { "status": "published" } },
    "must_not": [ { "term": { "archived": true } } ]
  }
}

medium

A. "must" should be an array, not an object

B. "filter" cannot be used with "must_not"

C. "must_not" should be an object, not an array

D. The query is correct as is

Solution

1. Step 1: Check must clause format

   The must clause expects an array of query objects, but here it is given as a single object.

2. Step 2: Validate other clauses

   The filter and must_not clauses are correctly formatted as an object and an array respectively.

3. Final Answer:

   "must" should be an array, not an object -> Option A

4. Quick Check:

   Must clause = array required [OK]

Hint: Must clause must always be an array [OK]

Common Mistakes:

• Using object instead of array for must
• Thinking filter and must_not conflict
• Using array for must_not incorrectly

5. You want to find documents where the category is 'books' and the price is less than 20, but exclude those that are out of stock. Which bool query correctly implements this?

hard

A. { "bool": { "should": [ { "term": { "category": "books" } }, { "range": { "price": { "lt": 20 } } } ], "must_not": [ { "term": { "stock": "out" } } ] } }

B. { "bool": { "filter": [ { "term": { "category": "books" } }, { "range": { "price": { "lt": 20 } } } ], "must_not": { "term": { "stock": "out" } } } }

C. { "bool": { "must": [ { "term": { "category": "books" } }, { "range": { "price": { "lt": 20 } } } ], "must_not": [ { "term": { "stock": "out" } } ] } }

D. { "bool": { "must": { "term": { "category": "books" } }, "filter": { "range": { "price": { "lt": 20 } } }, "must_not": [ { "term": { "stock": "out" } } ] } }

Solution

1. Step 1: Identify required conditions

   Documents must have category: books and price < 20. Both are required, so they go in must as an array.

2. Step 2: Exclude out of stock documents

   Documents with stock: out must be excluded, so use must_not with an array of term queries.

3. Step 3: Check each option

   { "bool": { "must": [ { "term": { "category": "books" } }, { "range": { "price": { "lt": 20 } } } ], "must_not": [ { "term": { "stock": "out" } } ] } } correctly uses must array for required conditions and must_not array for exclusion. { "bool": { "filter": [ { "term": { "category": "books" } }, { "range": { "price": { "lt": 20 } } } ], "must_not": { "term": { "stock": "out" } } } } uses filter which is okay but must_not is an object, not array. { "bool": { "should": [ { "term": { "category": "books" } }, { "range": { "price": { "lt": 20 } } } ], "must_not": [ { "term": { "stock": "out" } } ] } } uses should which makes conditions optional, wrong here. { "bool": { "must": { "term": { "category": "books" } }, "filter": { "range": { "price": { "lt": 20 } } }, "must_not": [ { "term": { "stock": "out" } } ] } } uses must as object and filter as object, mixing styles incorrectly.

4. Final Answer:

   { "bool": { "must": [ { "term": { "category": "books" } }, { "range": { "price": { "lt": 20 } } } ], "must_not": [ { "term": { "stock": "out" } } ] } } -> Option C

5. Quick Check:

   Must array + must_not array for exclusion [OK]

Hint: Use must array for required, must_not array to exclude [OK]

Common Mistakes:

• Using should instead of must for required filters
• Using object instead of array for must or must_not
• Mixing filter and must incorrectly