MySQL是目前最流行的開源關系型數據庫管理系統,被廣泛應用于各種Web應用程序中。在使用MySQL的過程中,我們需要掌握一些基本的概念和使用技巧,這里介紹MySQL的八大知識點。
一、數據庫的創建與刪除
CREATE DATABASE database_name; DROP DATABASE database_name;
二、數據表的創建與刪除
CREATE TABLE table_name ( column1 datatype, column2 datatype, column3 datatype, ... ); DROP TABLE table_name;
三、數據的插入、更新和刪除
INSERT INTO table_name (column1, column2, column3, ...) VALUES (value1, value2, value3, ...); UPDATE table_name SET column1 = value1, column2 = value2, ... WHERE condition; DELETE FROM table_name WHERE condition;
四、數據查詢語句
SELECT column1, column2, ... FROM table_name WHERE condition ORDER BY column1, column2, ... ASC|DESC LIMIT limit_num OFFSET offset_num;
五、聚合查詢語句
SELECT aggregate_function(column_name) FROM table_name WHERE condition GROUP BY column_name HAVING condition;
六、數據表的連接查詢
SELECT * FROM table1 JOIN table2 ON table1.column_name = table2.column_name;
七、MySQL函數的使用
CONCAT(string1, string2, ...) SUBSTR(string, start_position, length) UPPER(string) LOWER(string) COUNT(*) or COUNT(column_name) MAX(column_name) or MIN(column_name) AVG(column_name)
八、MySQL存儲過程和觸發器
DELIMITER $$ CREATE PROCEDURE procedure_name() BEGIN -- procedure body END$$ DELIMITER ; DELIMITER $$ CREATE TRIGGER trigger_name AFTER INSERT ON table_name FOR EACH ROW BEGIN -- trigger body END$$ DELIMITER ;
以上是MySQL的八大知識點,掌握了這些知識,我們就可以更加熟練地使用MySQL進行數據操作了。