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LEFT JOIN for Missing Records
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LEFT JOIN for Missing Records

EasySQL · PostgreSQL

Problem

Write a SQL query using a LEFT JOIN to identify records in a Students table that do not have corresponding entries in a Marks table.

Return each student without any marks record, including students whose IDs do not appear in Marks.

Output

  1. One row per unmatched student
  2. Columns: student_id, student_name
  3. Sort by student_id in ascending order

Schema

students
ColumnTypeDescription
student_idPKINTUnique identifier for the student
student_nameVARCHAR(100)Student's full name
grade_levelINTStudent's grade level
marks
ColumnTypeDescription
mark_idPKINTUnique identifier for the marks record
student_idINTStudent associated with the marks record
subjectVARCHAR(50)Subject for the recorded mark
scoreNUMERIC(5,2)Numerical score for the subject
Tablesstudentsmarks
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