The minute representation in the Database SQL statement should use Mi (a very important issue, which was previously considered to be the same as that in Java and can be expressed using mm); proofread rules (query Time Zone in case sensitive)

Java

The date indicated by the previous write Java code is YYYY-MM-DD hh: mm: SS

Mm (uppercase for month) and mm (lowercase for minutes)

SQL

But in SQL, the situation is completely different.

(Cause: the reason is that SQL statements are case-insensitive, so both mm and mm cannot be used, and the month should be defined as Mi)

We want to write the YYYY-MM-DD hh: MI: SS, using mi to represent minutes.

To_date ('1970-01-01 13:14:20 ', 'yyyy-mm-dd hh24: MI: ss ')

 

Bytes -----------------------------------------------------------------------------------------------

 

Description of the Case sensitivity issue, which leadsProofreading rules

 

Fuzzy search and normal query:

Mysql> select * From collage where coll_name like 'a % ';
+ --------- + ----------- +
| Coll_id | coll_name |
+ --------- + ----------- +
| 8 | AA |
| 9 | AA |
+ --------- + ----------- +
2 rows in SET (0.00 Sec)

Mysql> select * From collage where coll_name = 'a ';
+ --------- + ----------- +
| Coll_id | coll_name |
+ --------- + ----------- +
| 8 | AA |
| 9 | AA |
+ --------- + ----------- +
2 rows in SET (0.01 Sec)

No problem during data insertion :

Insert into collage values ('8', 'A ');

Insert into collage values ('9', 'A ');

 

 

Case sensitivity

Select * from a where a = 'abcde' collate chinese_prc_cs_ai -- case sensitive

Select * from a where a = 'abcde' collate chinese_prc_ci_ai -- case insensitive

Select * From collage where coll_name like 'a % 'collate gbk_bin; this isMySQLOfProofreading rules.

Mysql> select * From collage where coll_name like 'a %'Collate gbk_bin;
+ --------- + ----------- +
| Coll_id | coll_name |
+ --------- + ----------- +
| 8 | AA |
+ --------- + ----------- +

For UTF-8

utf8_bin 

You can specify rules when creating a table.

Create Table T1 (...)
Default Character Set Latin1Collate latin1_danish_ci;

For this table

Create Table Collage
(
Coll_id int not null auto_increment primary key,
Coll_name varchar (30) not null
) Engine = MyISAM
Default Character Set GBKCollateGbk_bin;

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