Question

表中的所有行都有type字段，该字段为0或1。

我需要在一个查询中计算0和1的行数。所以结果应该类似于：

type0 | type1
------+------
1234  | 4211

如何实施？

Answer 1

select type, count(type) from tbl_table group by type;

Answer 2

...承租人

SELECT
    SUM(CASE type WHEN 0 THEN 1 ELSE 0 END) AS type0,
    SUM(CASE type WHEN 1 THEN 1 ELSE 0 END) AS type1
FROM
   tableX;

未已经过测试。

Answer 3

您可能想要使用subqueries as scalar operands：

SELECT (SELECT COUNT(*) FROM table WHERE type = 0) AS type0,
       (SELECT COUNT(*) FROM table WHERE type = 1) AS type1;

在MySQL中测试如下：

CREATE TABLE t (id INT NOT NULL AUTO_INCREMENT, type INT);

INSERT INTO t VALUES (NULL, 0);
INSERT INTO t VALUES (NULL, 0);
INSERT INTO t VALUES (NULL, 1);
INSERT INTO t VALUES (NULL, 1);
INSERT INTO t VALUES (NULL, 1);

SELECT (SELECT COUNT(*) FROM t WHERE type = 0) AS type0,
       (SELECT COUNT(*) FROM t WHERE type = 1) AS type1;

+-------+-------+
| type0 | type1 |
+-------+-------+
|     2 |     3 | 
+-------+-------+
1 row in set (0.00 sec)

Answer 4

这样的结果很容易实现：

Type  Count
-----------
type0 1234
type1 4221

您可以使用以下内容：

SELECT CONCAT('type', [type]) as Type, COUNT(*) as Count
FROM MyTable
GROUP BY Type

MySQL：按字段计算行数

4 个答案: