通过分隔符 SQL 拆分值

Question

我有一个列 (varchar)，其值显示为 44:45:00。我正在编写一个查询，我想将 44:00:00 转换为十进制数并希望使用以下计算

((44(part1) * 60) + 45(part2) ) / 60 = 44,75

结果应该作为一个值返回，它不应该创建一个新列。

sql database

Answer 1

请使用这个：

架构：

create table x(t_hours varchar(20));
insert into x values('1:00:00');
insert into x values('1:00:00');
insert into x values('64:00:00');
insert into x values('2:00:00');
insert into x values('2:00:00');
insert into x values('1:30:00');
insert into x values('110:40:12');
insert into x values('44:38:24');
insert into x values('14:00:00');
insert into x values('8:00:00');
insert into x values('8:00:00');
insert into x values('47:00:00');
insert into x values('16:00:00');
insert into x values('1:00:00');
insert into x values('8:00:00');
insert into x values('16:00:00');
insert into x values('1:33:36');
insert into x values('19:46:48');
insert into x values('2:00:00');
insert into x values('2:00:00');
insert into x values('8:00:00');
insert into x values('8:00:00');
insert into x values('4:30:00');
insert into x values('6:30:00');
insert into x values('0:15:00');
insert into x values('1:00:00');
insert into x values('32:00:00');
insert into x values('8:00:00');
insert into x values('17:00:00');

查询：

select t_hours,left(t_hours,charindex(':',t_hours)-1)+ left(substring(t_hours,charindex(':',t_hours)+1,len(t_hours)-charindex(':',t_hours)),charindex(':',substring(t_hours,charindex(':',t_hours)+1,len(t_hours)-charindex(':',t_hours)))-1)/60.0
from x

输出：

t_hours	(No column name)
1:00:00	1.000000
1:00:00	1.000000
64:00:00	64.000000
2:00:00	2.000000
2:00:00	2.000000
1:30:00	1.500000
110:40:12	110.666666
44:38:24	44.633333
14:00:00	14.000000
8:00:00	8.000000
8:00:00	8.000000
47:00:00	47.000000
16:00:00	16.000000
1:00:00	1.000000
8:00:00	8.000000
16:00:00	16.000000
1:33:36	1.550000
19:46:48	19.766666
2:00:00	2.000000
2:00:00	2.000000
8:00:00	8.000000
8:00:00	8.000000
4:30:00	4.500000
6:30:00	6.500000
0:15:00	0.250000
1:00:00	1.000000
32:00:00	32.000000
8:00:00	8.000000
17:00:00	17.000000

db小提琴here

Answer 2

用这样的自定义分隔符试试这个：

DECLARE @foo VARCHAR(100) = '440:4500:00';
DECLARE @separator CHAR(1) = ':';

SELECT (CAST(SUBSTRING(@foo, 0, CHARINDEX(@separator, @foo)) AS INT) * 60
        + CAST(SUBSTRING(
                            @foo,
                            LEN(SUBSTRING(@foo, 0, CHARINDEX(@separator, @foo))) + 2,
                            CHARINDEX(@separator, @foo, LEN(SUBSTRING(@foo, 0, CHARINDEX(@separator, @foo))))
                        ) AS INT)
       )/ 60.0;

Answer 3

数据库支持字符串函数。子字符串函数通常称为substr() 或substring()（或两者兼有）。假设格式正是您指定的，您可以使用：

select (cast(substr(col, 1, 2) as int) +
        cast(substr(col, 4, 2) as int) / 60.0
       )

许多数据库都有方法来简化这一点。但这种方法应该适用于任何数据库。