MySQL查询将高度格式转换为厘米？
为此，请使用CAST()MySQL中的方法。让我们首先创建一个表-
mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, StudentHeight varchar(40) ) ;
使用插入命令在表中插入一些记录-
mysql> insert into DemoTable(StudentHeight) values('5\'10\"');
mysql> insert into DemoTable(StudentHeight) values('4\'6\"');
mysql> insert into DemoTable(StudentHeight) values('5\'8\"');使用select语句显示表中的所有记录-
mysql> select *from DemoTable;
这将产生以下输出-
+----+---------------+ | Id | StudentHeight | +----+---------------+ | 1 | 5'10" | | 2 | 4'6" | | 3 | 5'8" | +----+---------------+ 3 rows in set (0.00 sec)
以下是将高度格式转换为厘米的查询-
mysql> select
(cast(substr(StudentHeight,1,locate("'",StudentHeight)-1) as unsigned)*30.48)+
(cast(substr(StudentHeight,locate("'",StudentHeight)+1) as unsigned)*2.54) AS Centimeters
from DemoTable;这将产生以下输出-
+-------------+ | Centimeters | +-------------+ | 177.80 | | 137.16 | | 172.72 | +-------------+ 3 rows in set, 3 warnings (0.05 sec)