Mysql database field query case sensitive setting

Use navicat Create database , Character set selection utf8, If the sorting rule is not selected , Create successful session , Check the database properties and find that the sorting rules are set by default, as shown in the following figure ：

Once created , Create table testcase, adopt show CREATE TABLE testcase View the table creation statement , The following are not case sensitive [ Sort rule ：utf8_genera_ci Case insensitive ]

CREATE TABLE `testcase` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) DEFAULT NULL,
  `time` datetime DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `name` (`name`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8

INSERT INTO `testcase` ( `name`, `time`) VALUES ('WX0001', '2022-06-22');
INSERT INTO `testcase` ( `name`, `time`) VALUES ('wx0001', '2022-06-22');

Insert the statement above , Because it's not case sensitive , With a unique index field name Failed to insert the second record of

Modify table character set

ALTER TABLE testcase CONVERT TO CHARACTER SET utf8 COLLATE utf8_bin;

utf8_bin Store every character in the string in binary data , Case sensitive

How many rows does the database currently have , How many lines will be affected

CREATE TABLE `testcase` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) COLLATE utf8_bin DEFAULT NULL,
  `time` datetime DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `name` (`name`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8 COLLATE=utf8_bin

After modification , Insert the lowercase field value that just failed again
INSERT INTO `testcase` ( `name`, `time`) VALUES ('wx0001', '2022-06-22');

You can see that the insertion was successful , Case sensitivity is set successfully