计算有多少行具有相同的值

如何编写 SQL 查询来计算表的 num 列中特定 num 值的总数？

假设我们有以下数据。

姓名 NUM
SAM 1
鲍勃 1
JAKE 2
JOHN 4

请回答以下问题:

SELECT WHERE num = 1;

这将返回这两行。

姓名 NUM
SAM 1
鲍勃 1
290373 次浏览
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Try

SELECT NAME, count(*) as NUM FROM tbl GROUP BY NAME

SQL FIDDLE

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If you want to have the result for all values of NUM:

SELECT `NUM`, COUNT(*) AS `count`
FROM yourTable
GROUP BY `NUM`

Or just for one specific:

SELECT `NUM`, COUNT(*) AS `count`
FROM yourTable
WHERE `NUM`=1
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FOR SPECIFIC NUM:

SELECT COUNT(1) FROM YOUR_TABLE WHERE NUM = 1

FOR ALL NUM:

SELECT NUM, COUNT(1) FROM YOUR_TABLE GROUP BY NUM
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SELECT sum(num) WHERE num = 1;
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Try this Query

select NUM, count(1) as count
from tbl
where num = 1
group by NUM
--having count(1) (You condition)

SQL FIDDLE

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SELECT
COUNT(NUM) as 'result'
FROM
Table1
GROUP BY
NUM
HAVING NUM = 1
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SELECT SUM(IF(your_column=3,1,0)) FROM your_table WHERE your_where_contion='something';

e.g. for you query:-

SELECT SUM(IF(num=1,1,0)) FROM your_table_name;

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Use this query this will give your output:

select
t.name
,( select
count (*) as num_value
from Table
where num =t.num) cnt
from Table t;

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