例如,如果我们有一张桌子:

create table invoice_partitioned (id int
                                  , department_code INT
                                  , primary key(ID));

ALTER TABLE invoice_partitioned DROP PRIMARY KEY;

ALTER TABLE invoice_partitioned ADD PRIMARY KEY(id, department_code);

Here is a demo

这也将起作用:

ALTER TABLE invoice_partitioned
DROP PRIMARY KEY,
ADD PRIMARY KEY(id, department_code);

Demo

如果我用你的公式:D+M/60+S/3600 我认为D是度,M是分,S是秒。 选择此选项:

select SUBSTRING_INDEX('48° 52.250', '°',1) + 
       (SUBSTRING_INDEX('48° 52.250',' ',1)/60) +  
       (SUBSTRING_INDEX('48° 52.250','.',1)/3600);

或者对于您的数据库:

select SUBSTRING_INDEX(Latitude, '°', 1) + 
       (SUBSTRING_INDEX(Latitude ,' ',1)/60) +  
       (SUBSTRING_INDEX(Latitude ,'.',1)/3600) "DECIMAL_DEGREES"
FROM small_ocean_data;

我明白了 四十八点八一三三三三三三三三三三三三

48+0.8+0.01333333333333334

这是 DEMO