如何编写SQL查询以计算表的num列中特定num值的总数。
例如选择num = 1的位置
结果:2
+-----+-----+
| NAME | NUM |
+=====+=====+
| SAM | 1 |
+-----+-----+
| BOB | 1 |
+-----+-----+
| JAKE | 2 |
+-----+-----+
| JOHN | 4 |
+-----+-----+
如果你想获得NUM
的所有值的结果:
SELECT `NUM`, COUNT(*) AS `count`
FROM yourTable
GROUP BY `NUM`
或者仅针对一个特定的:
SELECT `NUM`, COUNT(*) AS `count`
FROM yourTable
WHERE `NUM`=1
对于特定数字:
SELECT COUNT(1) FROM YOUR_TABLE WHERE NUM = 1
对于所有NUM:
SELECT NUM, COUNT(1) FROM YOUR_TABLE GROUP BY NUM
SELECT
COUNT(NUM) as 'result'
FROM
Table1
GROUP BY
NUM
HAVING NUM = 1
试试这个查询
select NUM, count(1) as count
from tbl
where num = 1
group by NUM
--having count(1) (You condition)
SELECT sum(num) WHERE num = 1;
SELECT SUM(IF(your_column=3,1,0)) FROM your_table WHERE your_where_contion='something';
例如为您查询: -
SELECT SUM(IF(num=1,1,0)) FROM your_table_name;