14种SQL的进阶用法分享(更高效地处理数据)

SELECT column_name
FROM table_name
WHERE column_name = (SELECT column_name FROM sub_table WHERE condition);

SELECT s.name
FROM students s
WHERE s.course_id = (SELECT course_id FROM courses WHERE name = 'Math');

SELECT column_name
FROM table_name
WHERE column_name IN (SELECT column_name FROM sub_table WHERE condition);

SELECT s.name
FROM students s
WHERE s.course_id IN (SELECT course_id FROM courses WHERE name IN ('Math', 'Physics'));

SELECT column1, column2
FROM table1
INNER JOIN table2
ON table1.column1 = table2.column2;

SELECT s.name, c.name AS course_name
FROM students s
INNER JOIN courses c ON s.course_id = c.course_id;

SELECT column1, column2
FROM table1
LEFT JOIN table2
ON table1.column1 = table2.column2;

SELECT s.name, c.name AS course_name
FROM students s
LEFT JOIN courses c ON s.course_id = c.course_id;

SELECT SUM(column_name)
FROM table_name;

SELECT SUM(amount)
FROM sales;

SELECT AVG(column_name)
FROM table_name;

SELECT AVG(salary)
FROM employees;

SELECT column_name, COUNT(*)
FROM table_name
GROUP BY column_name;

SELECT department, COUNT(*)
FROM employees
GROUP BY department;

SELECT column_name, COUNT(*)
FROM table_name
GROUP BY column_name
HAVING COUNT(*) > 5;

SELECT department, COUNT(*)
FROM employees
GROUP BY department
HAVING COUNT(*) > 5;

SELECT column_name, RANK() OVER (PARTITION BY column_name ORDER BY another_column)
FROM table_name;

SELECT name, RANK() OVER (PARTITION BY department ORDER BY amount DESC)
FROM sales;

SELECT column_name,
       CASE
           WHEN condition1 THEN result1
           WHEN condition2 THEN result2
           ELSE default_result
       END AS calculated_column
FROM table_name;

SELECT name,
       CASE
           WHEN gender = 'Male' THEN salary * 0.9
           WHEN gender = 'Female' THEN salary * 1.1
           ELSE salary
       END AS adjusted_salary
FROM employees;

BEGIN TRANSACTION;

COMMIT;

ROLLBACK;

BEGIN TRANSACTION;
UPDATE table_name SET column_name = new_value WHERE condition;
COMMIT;

BEGIN TRANSACTION;
UPDATE table_name SET column_name = new_value WHERE condition;
IF @@ROWCOUNT > 0
    COMMIT;
ELSE
    ROLLBACK;
END TRANSACTION;

select * from movies order by movie_name asc;
qselect * from movies ORDER BY FIELD(movie name，'神话'，'猎场'，'芳华'，'花木兰!','铜雀台'，'警察故事'，'天下无贼'，'四大名捕'，'惊天解密'，'建国大业'，'功夫瑜伽'，'咱们结婚吧'，'赛尔号4';'疯狂机器城');

select * from movies ORDER BY actors, price desc;
select * from movies ORDER BY if(ISNULL(actors),0,1),actors, price;

select *,case when score>90 then '优秀'
            when score>80 then '良好'
            when score>60 then '一般'
            else '较差' end level
from student;

select actors,
GROUP CONCAT(movie name)，
GROUP_CONCAT(price) from movies GROUP BY actors;

select actors,
GROUP_CONCAT(movie_name order by price desc SEPARATOR '_'),
GROUP_CONCAT(price order by price desc SEPARATOR '_')
from movies GROUP BY actors;

SELECT actors,SUM(price) FROM movies GROUP BY actors;
SELECT actors,SUM(price) FROM movies GROUP BY actors WITH ROLLUP;

with m1 as (select * from movies where price > 50),
    m2 as (select * from movies where price >= 65)
select * from m1 where m1.id not in (select m2.id from m2) and m1.actors ='刘亦菲';

select * from movies where id >= 13;

INSERT INTO movies (id, movie_name,actors，price, release_date) VALUES
(13，'神话'，'成龙'，100，'2005-12-22');

INSERT IGNORE INTO movies (id, movie_name,actors,price,release_date) VALUES
(13，'神话'，'成龙'，100，'2005-12-22');

INSERT IGNORE INTO movies (id, movie_name, actors, price,release_date) VALUES
(14，"'神话2'，'成龙'，114，'2005-12-22');

REPLACE INTO movies (id, movie_name, actors, price, release_date) VALUES
(14，'神话2”，‘成龙'，100，‘2005-12-22');

REPLACE INTO movies (id, movie_name, actors, price, release_date) VALUES
(15，'神话3'，'成龙'，115，'2005-12-22');

INSERT INTO movies (id,movie_name, actors, price, release_date) VALUES
(15,'神话3'，'成龙'，115，'2005-12-22') on duplicate key update price = price + 10;

INSERT INTO movies (id,movie_name, actors, price, release_date) VALUES
(16,'神话4'，'成龙'，75，'2005-12-22') on duplicate key update price = price + 10;