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Asked: 2026-06-16T12:01:45+00:00

I am trying to write a SQL query that will turn this table: Start_time

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I am trying to write a SQL query that will turn this table:

Start_time    End_time   Instructor    Student  
9:00          9:35       Joe Bob       Andrew
9:00          9:35       Joe Bob       Smith
9:00          9:35       Roberto       Andy
10:00         10:35      Joe Bob       Angelica
11:00         11:20      Roberto       Bob

Into something like this:

Instructor    9:00              10:00         11:00
Joe Bob       Andrew, Smith     Angelica      NULL
Roberto       Andy              NULL          Bob

I think that this is some sort of PIVOT command but I am not sure how I should go about writing the SQL query. The times are all dynamically generated so I would prefer it if the query would generate the column names in the second table dynamically (for example, if the original table contained an additional start time of 11:30, there should be a new column for 11:30 in the result).

Thank you in advance, I’ve been playing with this for a while but couldn’t get it to work on my own. I can provide the SQL INSERT commands to give you the full data if necessary.

EDIT: It would be particularly helpful to get the result of this select statement as a VIEW. Thanks!

EDIT 2:
The code that is generating the view that makes the first table is:

CREATE VIEW schedule_view AS SELECT RTRIM(SUBSTRING(students.schedule_first_choice, 1, 5)) AS start_time, RTRIM(SUBSTRING(students.schedule_first_choice, -10, 5) AS end_time, CONCAT(instructors.first_name, ' ', instructors.last_name) AS instructor_name, 
    CONCAT(students.first_name, ' ', students.last_name) AS student_name , students.swim_america_level as class 
    FROM students, instructors WHERE students.instructor_id = instructors.instructor_id AND students.season = 
    (SELECT constant_value FROM constants WHERE constant_name = 'season') AND students.year = 
    (SELECT constant_value FROM constants WHERE constant_name = 'year')
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1 Answer

  1. Editorial Team
    SET @sql = NULL;
SELECT
  GROUP_CONCAT(DISTINCT
    CONCAT(
      'GROUP_CONCAT(case when Start_time = ''',
      Start_time,
      ''' then Student ELSE NULL end) AS ',
      CONCAT('`',Start_time,'`')
    )
  ) INTO @sql
FROM Table1;

SET @sql = CONCAT('SELECT Instructor, ', @sql, ' 
                   FROM Table1 
                   GROUP BY Instructor');

PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
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