6.1按条件筛选(与,或,非)
#数据筛选AND
SELECT *
FROM data1
WHERE city='shanghai' AND age>30;
#数据筛选IN
SELECT *
FROM data1
WHERE city IN ('shanghai','beijing');
#数据筛选OR
SELECT *
FROM data1
WHERE city='shanghai' OR age>30;
#数据筛选(不等于)
SELECT *
FROM data1
WHERE city !='beijing';
#数据筛选like(模糊筛选)
SELECT *
FROM data1
WHERE city LIKE 'bei%';
#筛选后计数countif
SELECT COUNT(id) AS id_count
FROM data1
WHERE city='shanghai' AND age>30;
#筛选后求和sumtif
SELECT SUM(price) AS price
FROM data1
WHERE city='beijing' AND age<30;
#筛选后求均值averageif
SELECT AVG(price) AS avg_price
FROM data1
WHERE city !='beijing';