Campaign Contact Streaks

SQL practice question · Hard · Gaps & Islands · Snowflake

campaign_touches has one row per marketing touch (user_id, touch_date); a user can be touched several times on the same day. For every user in the table, report the length in days of their longest run of consecutive calendar days with at least one touch (a user touched on isolated days has a longest streak of 1). Output columns: user_id, longest_streak. Order by user_id ascending.

Table: campaign_touches

Schema of campaign_touches
ColumnType
user_idINTEGER
touch_dateDATE
Sample rows of campaign_touches
user_idtouch_date
12026-01-01
12026-01-02
12026-01-03
12026-01-05
22026-01-01
22026-01-03
Expected output on the sample data
user_idlongest_streak
13
21

Solve it in the live editor on this page — run on sample data, then submit against hidden tests.

‹ Consecutive Compliance Filings · Three-Ingredient Meal Bundles ›

T
Tech Town
Log InSign Up Free
Home SQL Python DSA Power BI Snowflake Databricks Spark Gen AI Practice Problems Contest Question Asked in Interview Blog
SQL Interview Practice

Company-wise SQL questions

{{ totalCount }} questions in the style asked at Amazon, Microsoft, Google, Meta, Flipkart and more — {{ hardPct }}% Hard. Write SQL in a real database engine in your browser, run it on sample data, then evaluate against hidden tests.

🏆 Weekly SQL Contest
{{ totalCount }}
Questions
{{ companyCount }}
Companies
{{ prog.total.solved }}
Solved
Bookmark Question Companies Difficulty Category Status
{{ r.n }} - {{ r.title }} {{ c }} {{ r.difficulty }} {{ r.category }} {{ r.statusIcon }}
No questions match these filters.
Showing {{ rangeLabel }} of {{ filteredCount }}

Company tags show where this type of question is commonly reported in interviews. Questions, data and solutions are written by TechTown.
← All questions

{{ cur.n }} - {{ cur.title }}

🏆 Contest {{ contestWeek }}
{{ cur.catLabel }} {{ cur.diffLabel }} {{ c }}
Embed this questionPaste on a blog, course page or LMS. Free to use — educator guide 
{{ embedCode }}

{{ cur.statement }}

Table: {{ tb.name }}
ColumnType {{ c.name }}{{ c.type }}
{{ h }} {{ v.text }}
Expected output on the sample data:
{{ h }} {{ v.text }}
  • {{ h }}

No submissions yet. Press Evaluate to submit your query.
{{ s.verdict }} {{ s.meta }}
The solution unlocks after you solve this question or after 3 evaluations that didn't pass ({{ failCount }}/3 so far). Trying first is the fastest way to learn. 
{{ solutionSql }}
  1. {{ e }}
⏱ {{ timerLabel }}
{{ fnHelpTitle }}
{{ fnHelpText }}
Writing {{ dialectName }} · Ctrl/Cmd + Enter runs the query · Tab indents · your code is saved automatically
Output {{ out.status }}
  • {{ w }}
    •
{{ out.verdict }}
{{ out.detail }}
 
{{ out.error }}
Expected (sample data)
{{ h }}{{ v.text }}
Your output (sample data)
{{ h }}{{ v.text }}
{{ h }} {{ v.text }}
Run your query to see the result here.
🔒

To Track Your Progress, Log In / Sign Up

You have solved your 3 free questions — nice work! Log in (free) to unlock all 150 questions, keep your streak and appear on the leaderboard.

Sign Up Free Log In