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Tracks/Foundations

Foundations

SELECT, filter, sort, and limit — the queries every interview starts with.

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SELECT
WHERE
ORDER BY
LIMIT
DISTINCT

0/112 solved

  1. 1—001. Select All Employees
    easy
  2. 2—002. Filter Employees by Salary
    easy
  3. 3—003. Order Employees by Salary
    easy
  4. 4—005. Employees With Departments
    easy
  5. 5—006. Distinct Job Titles
    easy
  6. 6—007. Top 5 Highest-Paid Employees
    easy
  7. 7—008. Employees Hired After 2022
    easy
  8. 8—009. Employees Without a Manager
    easy
  9. 9—010. Total Salary Budget
    easy
  10. 10—011. Average Product Price
    easy
  11. 11—012. Most Expensive Product
    easy
  12. 12—013. Cheapest Product
    easy
  13. 13—014. Customer Count by Country
    easy
  14. 14—015. Products Out of Stock
    easy
  15. 15—016. Employees With No Department
    easy
  16. 16—017. Salary Tier Label
    easy
  17. 17—018. Customer Name Search
    easy
  18. 18—019. Orders in a Price Range
    easy
  19. 19—020. Customers from Specific Cities
    easy
  20. 20—021. Coalesce Missing Department Name
    easy
  21. 21—022. Uppercase Product Names
    easy
  22. 22—023. Extract Order Year
    easy
  23. 23—024. Total Orders per Customer
    easy
  24. 24—025. Count Unique Product Categories
    easy
  25. 25—026. Orders with Status Pending
    easy
  26. 26—027. Employees Earning Above 100k
    easy
  27. 27—028. Sort Products by Price Descending
    easy
  28. 28—029. Paginate Products (Page 3, 5 per page)
    easy
  29. 29—030. Monthly Order Count
    easy
  30. 30—101. String Length Function
    easy
  31. 31—102. UPPER and LOWER String Functions
    easy
  32. 32—103. Trim Leading and Trailing Whitespace
    easy
  33. 33—104. Concatenate First and Last Name
    easy
  34. 34—105. Extract Category Code from SKU
    easy
  35. 35—106. Replace Words in Review Text
    easy
  36. 36—107. Filter Orders by Date
    easy
  37. 37—108. Extract Year from Hire Date
    easy
  38. 38—109. Find Orders Placed in September
    easy
  39. 39—110. Calculate Project Duration in Days
    easy
  40. 40—111. Round Discounted Prices
    easy
  41. 41—112. Ceiling and Floor of Order Amounts
    easy
  42. 42—113. Find Accounts Far from Target Balance
    easy
  43. 43—114. Find Products with Quantity Divisible by 3
    easy
  44. 44—115. Calculate Square Area and Diagonal
    easy
  45. 45—116. Return First Available Phone Number
    easy
  46. 46—117. Avoid Division by Zero with NULLIF
    easy
  47. 47—118. Find Top-Level Employees with No Manager
    easy
  48. 48—119. Find Products with a Description
    easy
  49. 49—120. Filter Employees by Salary Range
    easy
  50. 50—121. Filter Products by Category Using IN
    easy
  51. 51—122. Exclude Cancelled and Returned Orders
    easy
  52. 52—123. Find Gmail Customers Using LIKE
    easy
  53. 53—124. Match Employee Codes with _ Wildcard
    easy
  54. 54—125. Find Products NOT Starting with S
    easy
  55. 55—126. Filter with Multiple AND Conditions
    easy
  56. 56—127. Filter with Multiple OR Conditions
    easy
  57. 57—128. Mix AND and OR with Parentheses
    easy
  58. 58—129. Total Amount Spent per Customer
    easy
  59. 59—130. Average Rating per Product
    easy
  60. 60—131. Most Recent Hire Date per Department
    easy
  61. 61—132. First Product Name Alphabetically per Category
    easy
  62. 62—133. COUNT(*) vs COUNT(column)
    easy
  63. 63—134. Count Distinct Customers
    easy
  64. 64—135. Map Status Codes to Labels with CASE WHEN
    easy
  65. 65—136. Assign Salary Grade with CASE WHEN Ranges
    easy
  66. 66—137. Handle NULL Bonus with CASE WHEN
    easy
  67. 67—138. Sort by Department and Salary
    easy
  68. 68—139. Sort Products by Profit Margin
    easy
  69. 69—140. Paginate Results with LIMIT and OFFSET
    easy
  70. 70—141. Top 5 Orders by Amount Using FETCH FIRST
    easy
  71. 71—142. Rename Columns with AS Alias
    easy
  72. 72—143. Use Table Aliases in a JOIN
    easy
  73. 73—144. Calculate Price Including Tax
    easy
  74. 74—145. Join Orders with Customer Details
    easy
  75. 75—146. Find Customers Who Have Never Ordered
    easy
  76. 76—147. List All Unique Order Statuses
    easy
  77. 77—148. Find Unique Department-City Combinations
    easy
  78. 78—149. Count Orders by Status
    easy
  79. 79—150. Total Revenue by Department and Quarter
    easy
  80. 80—151. Customers Who Spent More Than $500
    easy
  81. 81—152. Products Ordered by More Than 2 Customers
    easy
  82. 82—153. Group Orders by Month Using DATE_TRUNC
    easy
  83. 83—154. Find Active Subscriptions After a Date
    easy
  84. 84—155. Pad Invoice Numbers with LPAD
    easy
  85. 85—156. Reverse Strings and Detect Palindromes
    easy
  86. 86—157. Find the Position of @ in Email Addresses
    easy
  87. 87—158. CHAR_LENGTH vs LENGTH on Messages
    easy
  88. 88—159. Replace NULL Commission with IFNULL
    easy
  89. 89—160. Find Employees Earning Above Average Salary
    easy
  90. 90—301. Compute Profit per Product
    easy
  91. 91—303. Find Employees in a Named Department
    easy
  92. 92—304. Products Below Reorder Level
    easy
  93. 93—305. Extract Day of Week from Order Date
    easy
  94. 94—306. Find Customers with No Phone Number
    easy
  95. 95—307. Calculate Salary After a 10% Bonus
    easy
  96. 96—308. Products Whose Name Starts with 'A'
    easy
  97. 97—310. Filter Orders by a Specific Date
    easy
  98. 98—311. Sort Employees by Hire Date
    easy
  99. 99—313. Find the Highest and Lowest Salary
    easy
  100. 100—314. Customers with Long Names
    easy
  101. 101—315. Uppercase Product Names
    easy
  102. 102—316. Score Remainder with the Modulo Operator
    easy
  103. 103—317. Calculate the Discount Amount per Product
    easy
  104. 104—319. Orders in a Date Range (BETWEEN)
    easy
  105. 105—320. Count NULL Values in a Column
    easy
  106. 106—321. Assign Letter Grades with CASE WHEN
    easy
  107. 107—322. Fetch the First 3 Products Alphabetically (LIMIT)
    easy
  108. 108—323. Filter Employees by Status Using IN
    easy
  109. 109—324. Format Order IDs with Zero-Padding
    easy
  110. 110—327. Pick the First Non-NULL Name with COALESCE
    easy
  111. 111—329. Customers Who Have Placed at Least One Order
    easy
  112. 112—330. Combine Employees and Contractors with UNION
    easy