Comprehensive Analysis of MySQL CRUD: A Quick Guide for Beginners to Master Data Insert, Update, Delete, and Query
This article introduces MySQL CRUD operations (Create, Read, Update, Delete), which are fundamental to data management. The four core operations correspond to: Create (insertion), Read (query), Update (modification), and Delete (removal). First, the preparation work: create a `students` table (with auto-incrementing primary key `id`, `name`, `age`, and `class` fields) and insert 4 test records. **Create (Insert)** : Use the `INSERT` statement, which supports single-row or batch insertion. Ensure field and value correspondence; strings should be enclosed in single quotes, and auto-incrementing primary keys can be specified as `NULL` (e.g., `INSERT INTO students VALUES (NULL, 'Xiao Fang', 15, 'Class 4')`). **Read (Query)** : Use the `SELECT` statement. The basic syntax is `SELECT 字段 FROM 表`, supporting conditional filtering (`WHERE`), sorting (`ORDER BY`), fuzzy queries (`LIKE`), etc. For example: `SELECT * FROM students WHERE age > 18`. **Update (Update)** : Use the `UPDATE` statement with syntax `UPDATE 表 SET 字段=值 WHERE 条件`. **Without a `WHERE` clause, the entire table will be modified** (e.g., `UPDATE students SET age=18 WHERE name='Xiao Gang'`). **Delete (Delete)** :
Read MoreLearning MySQL from Scratch: Mastering Data Extraction with Query Statements
This article introduces the basics of MySQL. First, it explains that MySQL is an open-source relational database used for storing structured data (such as users, orders, etc.). Before use, it needs to be installed and run, and then connected through graphical tools or command lines. Data is stored in the form of "tables", which are composed of "fields" (e.g., id, name). For example, a student table includes fields like student ID and name. Core query operations include: basic queries (`SELECT * FROM table_name` to retrieve all columns, `SELECT column_name` to specify columns, `AS` to set aliases); conditional queries (`WHERE` combined with comparison operators, logical operators, and `LIKE` for fuzzy matching to filter data); sorting (`ORDER BY`, default ascending `ASC`, descending with `DESC`); limiting results (`LIMIT` to control the number of returned rows); and deduplication (`DISTINCT` to exclude duplicates). It also provides comprehensive examples and practice suggestions, emphasizing familiarizing oneself with query logic through table creation testing and combined conditions. The core of MySQL queries: clarify requirements → select table → specify columns → add conditions → sort/limit. With more practice, one can master query operations proficiently.
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