Why compound queries combine conditions in Elasticsearch - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to add a must condition inside the bool query.

Elasticsearch

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

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

A{"match": {"title": "Elasticsearch"}}

B{"term": {"status": "active"}}

C{"range": {"date": {"gte": "now-1d/d"}}}

D{"exists": {"field": "user"}}

Attempts:

3 left

💡 Hint

Common Mistakes

Using a condition outside an array

Using filter instead of must

The must clause requires the condition to be matched. Here, a match query on the title field is added.

2fill in blank

medium

Complete the code to add a filter condition that matches documents with status 'active'.

Elasticsearch

{
  "query": {
    "bool": {
      "filter": [
        [1]
      ]
    }
  }
}

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

A{"term": {"status": "active"}}

B{"match": {"status": "active"}}

C{"range": {"status": {"gte": "active"}}}

D{"exists": {"field": "status"}}

Attempts:

3 left

💡 Hint

Common Mistakes

Using match which is analyzed

Using range for exact match

The filter clause uses a term query to exactly match the status field to 'active'.

3fill in blank

hard

Fix the error in the bool query by completing the missing must_not condition.

Elasticsearch

{
  "query": {
    "bool": {
      "must": [
        {"match": {"title": "search"}}
      ],
      "must_not": [
        [1]
      ]
    }
  }
}

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

A{"match": {"status": "active"}}

B{"exists": {"field": "user"}}

C{"range": {"date": {"lte": "now-1M/M"}}}

D{"term": {"status": "inactive"}}

Attempts:

3 left

💡 Hint

Common Mistakes

Using match instead of term

Putting conditions in wrong clauses

The must_not clause excludes documents with status exactly 'inactive' using a term query.

4fill in blank

hard

Fill both blanks to create a bool query with must and filter conditions.

Elasticsearch

{
  "query": {
    "bool": {
      "must": [
        [1]
      ],
      "filter": [
        [2]
      ]
    }
  }
}

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

A{"match": {"content": "python"}}

B{"term": {"status": "published"}}

C{"range": {"date": {"gte": "2023-01-01"}}}

D{"exists": {"field": "author"}}

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping must and filter conditions

Using match in filter

The must clause requires documents containing 'python' in content. The filter clause limits results to those with status exactly 'published'.

5fill in blank

hard

Fill all three blanks to build a bool query combining must, filter, and must_not conditions.

Elasticsearch

{
  "query": {
    "bool": {
      "must": [
        [1]
      ],
      "filter": [
        [2]
      ],
      "must_not": [
        [3]
      ]
    }
  }
}

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

A{"match": {"description": "database"}}

B{"term": {"status": "active"}}

C{"term": {"category": "deprecated"}}

D{"range": {"created": {"gte": "2024-01-01"}}}

Attempts:

3 left

💡 Hint

Common Mistakes

Putting must_not condition in filter

Using range instead of term for category

The must clause searches for 'database' in description. The filter clause limits to documents with status 'active'. The must_not clause excludes documents in the 'deprecated' category.

Practice

1. What is the main purpose of using compound queries in Elasticsearch?

easy

A. To combine multiple conditions for more precise search results

B. To speed up the indexing process

C. To delete documents from the index

D. To create new indexes automatically

Solution

1. Step 1: Understand the role of compound queries

   Compound queries allow combining several conditions to refine search results.

2. Step 2: Identify the main benefit

   Combining conditions helps find exactly what you want by mixing rules.

3. Final Answer:

   To combine multiple conditions for more precise search results -> Option A

4. Quick Check:

   Compound queries = combine conditions [OK]

Hint: Compound queries mix conditions to narrow search [OK]

Common Mistakes:

• Thinking compound queries speed up indexing
• Confusing compound queries with index creation
• Believing compound queries delete documents

2. Which of the following is the correct syntax to combine conditions using a bool query in Elasticsearch?

easy

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

B. {"combine": {"and": [{"match": {"field": "value"}}]}}

C. {"query": {"combine": [{"match": {"field": "value"}}]}}

D. {"bool": {"combine": [{"match": {"field": "value"}}]}}

Solution

1. Step 1: Recall the correct bool query syntax

   The bool query uses keys like must, should, must_not, and filter inside a bool object.

2. Step 2: Match the syntax with options

   {"bool": {"must": [{"match": {"field": "value"}}]}} correctly uses "bool" with "must" and a match clause.

3. Final Answer:

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

4. Quick Check:

   Bool query uses must inside bool [OK]

Hint: Bool query uses must, should, must_not, filter keys [OK]

Common Mistakes:

• Using 'combine' instead of 'bool'
• Placing conditions outside bool
• Wrong nesting of match inside combine

3. Given this Elasticsearch bool query, what documents will it match?

{"bool": {"must": [{"match": {"title": "apple"}}], "must_not": [{"match": {"status": "sold"}}]}}

medium

A. Documents with title 'apple' and status 'sold'

B. Documents with title containing 'apple' and status not 'sold'

C. Documents with title 'apple' or status 'sold'

D. Documents with status 'sold' only

Solution

1. Step 1: Analyze the must clause

   The must clause requires the title field to match 'apple'.

2. Step 2: Analyze the must_not clause

   The must_not clause excludes documents where status matches 'sold'.

3. Final Answer:

   Documents with title containing 'apple' and status not 'sold' -> Option B

4. Quick Check:

   Must + must_not = include and exclude [OK]

Hint: Must means include; must_not means exclude [OK]

Common Mistakes:

• Confusing must_not as must
• Thinking must_not includes documents
• Mixing OR logic instead of AND

4. Identify the error in this Elasticsearch bool query:

{"bool": {"must": {"match": {"name": "john"}}, "should": [{"term": {"age": 30}}]}}

medium

A. "match" is not valid inside "must"

B. "should" cannot be used with "must"

C. "must" should be an array, not a single object

D. The query is correct as is

Solution

1. Step 1: Check the structure of must clause

   The must clause expects an array of conditions, but here it is a single object.

2. Step 2: Verify should clause usage

   The should clause is correctly an array, so no error there.

3. Final Answer:

   "must" should be an array, not a single object -> Option C

4. Quick Check:

   Must requires array of conditions [OK]

Hint: Must and should clauses expect arrays [OK]

Common Mistakes:

• Using object instead of array for must
• Thinking should can't be with must
• Misplacing match inside must

5. You want to find documents where the field "category" is "books" and either "author" is "Alice" or "year" is 2020, but exclude those with "status" as "archived". Which bool query correctly combines these conditions?

hard

A. {"bool": {"should": [{"term": {"category": "books"}}, {"term": {"author": "Alice"}}, {"term": {"year": 2020}}], "must_not": [{"term": {"status": "archived"}}]}}

B. {"bool": {"must": [{"term": {"category": "books"}}, {"term": {"author": "Alice"}}], "must_not": [{"term": {"status": "archived"}}]}}

C. {"bool": {"filter": [{"term": {"category": "books"}}], "must": [{"term": {"author": "Alice"}}, {"term": {"year": 2020}}], "must_not": [{"term": {"status": "archived"}}]}}

D. {"bool": {"must": [{"term": {"category": "books"}}], "should": [{"term": {"author": "Alice"}}, {"term": {"year": 2020}}], "must_not": [{"term": {"status": "archived"}}]}}

Solution

1. Step 1: Identify the required conditions

   Must have category = books, should have author = Alice or year = 2020, and must_not have status = archived.

2. Step 2: Match conditions to bool clauses

   Category is mandatory (must), author or year is optional but at least one (should), and status excluded (must_not).

3. Final Answer:

   {"bool": {"must": [{"term": {"category": "books"}}], "should": [{"term": {"author": "Alice"}}, {"term": {"year": 2020}}], "must_not": [{"term": {"status": "archived"}}]}} -> Option D

4. Quick Check:

   Must + should + must_not combined correctly [OK]

Hint: Must = required, should = optional OR, must_not = exclude [OK]

Common Mistakes:

• Putting author in must instead of should
• Using filter instead of must for category
• Putting all conditions in should