Deleting Earliest Incomplete or Brief Exam Records Using MySQL DELETE with ORDER BY and LIMIT

Consider an exam record table exam_record that logs user attempts over several year. The table has the folowing structure: Field Type Null Key Extra Default Comment id int(11) NO PRI auto_increment (NULL) Auto-increment ID uid int(11) NO (NULL) User ID exam_id int(11) NO (NULL) Exam ID start_time datetime NO (NULL) Start time ...

Posted on Fri, 14 Aug 2026 16:06:04 +0000 by stonelord

SQL Query Fundamentals: SELECT, WHERE, Aggregation, Grouping, Sorting, and Limiting

This document covers essential SQL query operations, including selectign data, filtering with conditions, aggregating results, grouping data, ordering output, and limiting the number of rows returned. Basic SELECT Syntax The fundamental SELECT statement retrieves data from a table. The * wildcard selects all columns, while specific column names ...

Posted on Thu, 28 May 2026 22:12:24 +0000 by merkinmuffley