用于排序的varchar到数字转换

Question

我有一个查询订购column:

select * from mytable order by column asc — sort table

column type是varchar,所以输出是:

1
10
100
11
12
13

如果我希望它们按数值排序,我应该如何排序,因此输出为:

1
10
11
12
13
100

Answer 1

使用:

order by cast(column as unsigned) asc

Answer 2

如果您只想将其column视为INT:

SELECT * FROM mytable ORDER BY column+0;
1
10
11
12
13
100

或者这个,如果你想治疗column既INT和VARCHAR

SELECT * FROM mytable ORDER BY column+0, column; #this will sort the column by VARCHAR first and then sort it by INT

abc
xyz
1
10
11
12
13
100

Answer 3

这也应该有效:

order by (0 + column) asc

Answer 4

如果我们只是稍微通过声明修改顺序(在字段顺序中添加"+0"),您可以强制MySQL自然地对字段进行排序.

 > select * from mytable order by column+0 asc;
 column
 1 
 10
 11
 12
 13 
 100