The id field in the database table should be stored as 1.1.1.1. The foreground shows that the order should be arranged in ascending order, and the null judgment should be repeated. Please see if my existing ideas are correct. - Codes Helper - Programming Question Answer

The id field in the database table should be stored as 1.1.1.1. The foreground shows that the order should be arranged in ascending order, and the null judgment should be repeated. Please see if my existing ideas are correct.

the receptionist wants to display as

set five fields of id1,id2,id3,id4,id,

id is the primary key and type is varchar.

id1,2,3,4 type is int.

foreground ascending order: select id1,id2,id3,id4,id from t_task group by 1, 2, 3, 4

if you want to add a new piece of data, when the foreground enters "1.1.1.1", it is transmitted to the background in the form of a string. Convert the characters of the string 1, 3, 5, 5 and 7 into the int type. If not, set it to empty. The "1.1.1.1" stored in the id1,id2,id3,id4, entry is directly stored in the id field in the format of the string, and then the null judgment is repeated by the way. If the input format of the foreground is incorrect, you should also remind you to report an error, and the background processing and judgment should be written in java

.

if there is only one "1", save it as 1? The display is also 1, and the id1 must be greater than 0. if the last three digits are empty, they will be set to empty.

I wonder if my preliminary idea is correct? Also ask the god for advice, thank you!

Oct.14,2021

Why is the

1 sort followed by group by ? what the heck is this? Since
2 is a numerical sort, if not, it should be set to 0

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