to_tsquery for search terms in PostgreSQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a text search query for the term 'cat'.

PostgreSQL

SELECT to_tsquery([1]);

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

A"cat"

Bcat

C'cat & dog'

D'cat'

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting the single quotes around the search term.

Using double quotes instead of single quotes.

The to_tsquery function requires the search term as a string literal, so it must be enclosed in single quotes.

2fill in blank

medium

Complete the code to create a text search query for the phrase 'cat & dog'.

PostgreSQL

SELECT to_tsquery([1]);

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

A'cat dog'

B'cat | dog'

C'cat & dog'

D'cat && dog'

Attempts:

3 left

💡 Hint

Common Mistakes

Using spaces without operators between words.

Using double ampersands instead of a single ampersand.

The & operator in to_tsquery means AND, so the phrase must be written as 'cat & dog' inside single quotes.

3fill in blank

hard

Fix the error in the code to correctly create a text search query for 'cat | dog'.

PostgreSQL

SELECT to_tsquery([1]);

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

A'cat | dog'

B'cat or dog'

C'cat & dog'

Dcat | dog

Attempts:

3 left

💡 Hint

Common Mistakes

Using the word 'or' instead of the | operator.

Not enclosing the query in single quotes.

The OR operator in to_tsquery is |, and the entire query must be a string literal in single quotes.

4fill in blank

hard

Fill both blanks to create a text search query that searches for 'cat' AND 'dog' but NOT 'mouse'.

PostgreSQL

SELECT to_tsquery([1]); -- 'cat & dog [2] mouse'

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

A'cat & dog'

B'cat | dog'

C&!

D|!

Attempts:

3 left

💡 Hint

Common Mistakes

Using '|!' instead of '&!' for AND NOT.

Not combining operators correctly.

The AND operator is & and NOT is !. To combine them, use &! to mean AND NOT. The query string should be 'cat & dog &! mouse'.

5fill in blank

hard

Fill all three blanks to create a text search query that searches for 'cat' OR 'dog' AND excludes 'mouse'.

PostgreSQL

SELECT to_tsquery([1]); -- 'cat [2] dog [3] mouse'

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

A'cat'

B'dog'

C|!

D|

Attempts:

3 left

💡 Hint

Common Mistakes

Using AND operator instead of OR.

Not combining OR and NOT correctly.

The OR operator is | and to exclude a term, use NOT !. To combine OR and NOT, use |!. The query string is 'cat | dog |! mouse'.

Practice

1. What does the to_tsquery function do in PostgreSQL?

easy

A. It converts search terms into a format for full-text search queries.

B. It creates a new table for storing search terms.

C. It updates text columns with search keywords.

D. It deletes rows that match search terms.

Solution

1. Step 1: Understand the purpose of to_tsquery

   to_tsquery converts plain search words into a special query format that PostgreSQL can use for full-text searching.

2. Step 2: Compare options with the function's role

   Only It converts search terms into a format for full-text search queries. correctly describes this conversion role. Other options describe unrelated database actions.

3. Final Answer:

   It converts search terms into a format for full-text search queries. -> Option A

4. Quick Check:

   to_tsquery = converts search terms [OK]

Hint: Remember: to_tsquery prepares search words for text search [OK]

Common Mistakes:

• Thinking it creates or modifies tables
• Confusing it with data update or delete operations
• Assuming it returns raw text instead of a query format

2. Which of the following is the correct syntax to create a to_tsquery for searching the words 'cat' AND 'dog' using the explicit AND operator?

easy

A. to_tsquery('cat | dog')

B. to_tsquery('cat & dog')

C. to_tsquery('cat dog')

D. to_tsquery('cat && dog')

Solution

1. Step 1: Recall the AND operator in to_tsquery

   The AND operator is represented by & in to_tsquery syntax.

2. Step 2: Match the correct syntax

   to_tsquery('cat & dog') uses & correctly between 'cat' and 'dog'. to_tsquery('cat | dog') uses OR, C misses operator, and D uses invalid &&.

3. Final Answer:

   to_tsquery('cat & dog') -> Option B

4. Quick Check:

   AND = & in to_tsquery [OK]

Hint: Use & for AND, | for OR in to_tsquery strings [OK]

Common Mistakes:

• Using spaces without operators to mean AND
• Using double ampersands (&&) instead of single &
• Confusing OR (|) with AND (&)

3. Given the query:
SELECT to_tsquery('fast & !slow');
What is the expected output?

medium

A. 'fast' | !'slow'

B. Syntax error

C. 'fast' & !'slow'

D. 'fast slow'

Solution

1. Step 1: Understand the operators in the query

   The query uses AND (&) between 'fast' and NOT (!) 'slow'. This means search for 'fast' but exclude 'slow'.

2. Step 2: Check the output format of to_tsquery

   PostgreSQL returns the query as a string with words quoted and operators preserved. So output is 'fast' & !'slow'.

3. Final Answer:

   'fast' & !'slow' -> Option C

4. Quick Check:

   AND = & and NOT = ! in output [OK]

Hint: NOT is !, AND is & in to_tsquery output [OK]

Common Mistakes:

• Confusing OR (|) with AND (&)
• Expecting raw words without quotes
• Thinking the query causes syntax error

4. Identify the error in this query:
SELECT to_tsquery('apple & | orange');

medium

A. Syntax error due to consecutive operators & |

B. No error, valid query

C. Error because words must be uppercase

D. Error because to_tsquery needs two arguments

Solution

1. Step 1: Analyze the operator usage in the query string

   The string has & | operators consecutively without a word between them, which is invalid syntax.

2. Step 2: Confirm PostgreSQL behavior

   PostgreSQL will raise a syntax error because operators must separate valid search terms, not each other.

3. Final Answer:

   Syntax error due to consecutive operators & | -> Option A

4. Quick Check:

   Operators must separate words, not each other [OK]

Hint: Avoid placing operators consecutively without words [OK]

Common Mistakes:

• Assuming multiple operators in a row are allowed
• Thinking case of words matters
• Believing to_tsquery requires multiple arguments

5. You want to search for documents containing the word 'run' but not 'running'. Which to_tsquery expression correctly achieves this?

hard

A. to_tsquery('run ! running')

B. to_tsquery('run | !running')

C. to_tsquery('run & !run')

D. to_tsquery('run & !running')

Solution

1. Step 1: Understand the requirement

   You want documents that contain 'run' but exclude those that contain 'running'. This means AND 'run' and NOT 'running'.

2. Step 2: Choose the correct operator usage

   AND is & and NOT is !. to_tsquery('run & !running') uses these correctly. to_tsquery('run | !running') uses OR which is wrong. to_tsquery('run & !run') excludes 'run' itself. to_tsquery('run ! running') has invalid syntax (missing operator between 'run' and '!').

3. Final Answer:

   to_tsquery('run & !running') -> Option D

4. Quick Check:

   AND = & and NOT = ! for correct filtering [OK]

Hint: Use & for AND, ! for NOT to exclude terms [OK]

Common Mistakes:

• Using OR instead of AND for inclusion
• Excluding the main word accidentally
• Missing operators between words