What should I do if the mysql query time comes out with numbers?
The solution to mysql query time to get numbers: first query the digital time from the database; then use the “function timestampToTime(timestamp){…}” method in the front end to convert the timestamp to time. Recommendation: “Mysql Video Tutorial” The time of the database query is displayed as a string of numbers on the front end? Solution: I encountered a problem before, the time queried from the database was displayed as a number on the front end. The database I use is mysql, and my solution is to convert it at the front end. The code is as follows: The string of numbers queried is a timestamp. You only need to convert the timestamp to time at the foreground. . function timestampToTime(timestamp) { var date = new Date(timestamp);//If the timestamp is 10 digits, you need *1000, if the timestamp is 13 digits, you don’t need to multiply by 1000 Y = date.getFullYear() + '/'; M = (date.getMonth()+1 <10 ? '0'+(date.getMonth()+1) : date.getMonth()+1) + '/' ; D = date.getDate() + ' '; h = date.getHours() + ':'; m = date.getMinutes() + ':'; s = date. getSeconds(); return Y+M+D; } It should be noted that the query timestamp is 10 digits or 13 digits!…
How does mysql take out the database backup sql
mysql sql php Write your review! Let’s make a fuss, see everything Member Login | User Registration recommended reading io MySQL function to obtain the current time of the system [MySQL] Database | mysql tutorial time, system database-mysql tutorial bitsCN.comMySQL function to get the current time of the system Environment: MySQLServer5.1 Question: The function of MySQL to get the current time of the system … [detailed] Crayon Shinchan 2023-08-26 13:03:19 io OracleStudy case – BITMAP under OracleASSM management mode Database | mysql tutorial OracleStudy, case, –OracleASSM, manage database-mysql tutorial servletcontext source code, ubuntu release invalid memory, tomcat cat litter … [detailed] Crayon Shinchan 2023-08-26 12:52:50
How to add mysql to the Red Hat system
The method of adding mysql in the Red Hat system: first log in to the Red Hat system as the root user; then create the mysql user and mysql group; then set the data storage directory; finally enter the mysql directory, manually execute the database initialization script and You can modify the relevant configuration files. mysql configuration file is fragmented and centralized (can be configured for multiple services) [mysql]——client configuration [mysqld]——server configuration [client]——effective for all client programs The order in which mysql reads configuration files:/etc/my.cnf –> /etc/ mysql/my.cnf–> $BASEDIR/my.cnf (usually the installation directory)–> ~/.my.cnf (the configuration file in the user’s home directory, even if the mysql user does not have Also look for the home directory) If the four configuration files found conflict, the last one shall prevail (the latter one overrides the previous oneEven without any configuration files, mysql can run, and a bunch of default configuration files are provided in the support-files directory Copy a configuration file to /etc/my.cnf cp support-files/my-large.cnf /etc/my.cnf Edit and modify the configuration file vi /etc/my.cnf It is very important to add data directory configuration information to the [mysqld] segmentdatadir = /data directory 9. Start the mysqld service service mysqld startCheck the startup statusnetstat…
How to quickly query mysql
Mysql quick query method: 1. Query the running transaction; 2. View the current connection, and know the number of connections; 3. View the size of a table; 4. View all tables of a database size. More related free learning recommendation: mysql tutorial (video) mysql quick query Method: 1. Query running transactions select p.id,p.user,p .host,p.db,p.command,p.time,i.trx_state,i.trx_started,p.info from information_schema.processlist p,information_schema.innodb_trx i where p.id=i.trx_mysql_thread_id; 2. Check the current connection and be able to know the number of connections select SUBSTRING_INDEX(host,’:’,1) as ip , count(*) from information_schema.processlist group by ip; 3. Check the size of a table select concat(round(sum(DATA_LENGTH/1024/ 1024), 2), ‘M’) from information_schema.tables where table_schema=’database name’ AND table_name=’table name’; 4. Check the size of all tables in a database select table_name,concat(round(sum(DATA_LENGTH/1024/1024),2),’M’) from information_schema.tables where table_schema=’t1′ group by table_name ; 5. Check the size of the library and the size of the remaining space select table_schema, round((sum(data_length / 1024 / 1024 ) + sum(index_length / 1024 / 1024)), 2) dbsize, round(sum(DATA_FREE / 1024 / 1024), 2) freesize, round((sum(data_length / 1024 / 1024) + sum(index_length / 1024 / 1024) + sum(DATA_FREE / 1024 / 1024)), 2) spsize from information_schema.tables where table_schema not in (‘mysql’, ‘information_schema’, ‘performance_schema’) group by table_schema order by freesize desc; 6. Find about…
How to run mysql5.7 installation
How to install and run mysql5.7: first unzip the installation package to a certain directory, and initialize the database; then set a root random password, and start the mysqld service; then log in to Mysql and reset the root password; finally Install windows service and set remote access permissions. More related free learning recommendation: mysql tutorial (video) mysql5.7 How to install and run: 1. Unzip to a certain directory, such as: D:\tools\mysql-5.7.11-winx64 2.mysql5. Version 7 compressed package, there is no data folder by default, you need to initialize the database first, the command is as follows: D:\tools\mysql-5.7.11-winx64\ bin> mysqld –initialize 3. After initialization, a data folder will be generated under the mysql-5.7.11-winx64 folder. The root password of the mysql5.7 version is disabled by default. It is empty, but a random password. The password can be viewed in the “machine name.err” file under the data folder. The content is as follows: 2016-02-26T03:23:56.025673Z 1 [Note] A temporary password is generated for root@localhost: yai/UnHse8Nu 4. Start mysqld service D:\tools\mysql-5.7.11-winx64\bin> mysqld –console 5. Use the random password to log in to mysql, command As follows: D:\tools\mysql-5.7.11-winx64\bin> mysql -uroot -pyai/UnHse8Nu 6 .After logging in, you need to reset the root password before you can use…
How to convert function of Mysql number type
Mysql number type conversion function method: 1. Use the function concat to convert Int to varchar; 2. Use [cast(a as signed) a] to convert varchar to Int. More related free learning recommendation: mysql tutorial (video) Mysql number type Method of conversion function: 1. Convert Int to varchar often use the concat function, such as concat(8,'0') to get the string '80& #39; and MENU_NAME LIKE CONCAT(CONCAT('%', #{pd.keywords}),' %') 2. Convert varchar to Int and use cast(a as signed) a to varchar type string Summary: type conversion is the same as SQL Server, The type parameter is a bit different: CAST(xxx AS type), CONVERT(xxx, type) Available types Binary, same effect with binary prefix: BINARY Character type, can take parameters: CHAR() Date: DATE Time: TIME DateTime: DATETIME Float: DECIMAL Integer: SIGNED Unsigned Integer: UNSIGNED SELECT * from sys_menu where PARENT_ID='0' ORDER BY cast(MENU_NO as signed) When MENU_NO is a letter or Chinese character, the converted number is 0. 3. When we want to modify the sorting of a user list frequently, we need It is used when the serial number is a decimal. Because if it is an integer, then after adjusting the first one, all subsequent numbers must be adjusted. So we…
Mysql how to create password error
How to create a wrong password for mysql: first open the terminal, enter the code [mysql> flush privileges; refresh privileges]; then re-enter the set password. Mysql creates a password error method: In the settings mysql> set password for root@localhost = password('admin'); An error occurred: The MySQL server is running with the –skip-grant-tables option so it cannot execute this statement Solution: mysql> flush privileges; Refresh privileges Re-enter the setting password. More related free learning recommendations: mysql tutorial (video) The above is the detailed content of how mysql creates password errors. For more information, please pay attention to 1024programmer. com Other related articles!
How to query fields with mysql wildcards
Mysql wildcard query field method: 1. Use [%] to indicate that any character appears any number of times, the code is [WHERE title like '%Zhang San']; 2. Use [_ 】Indicates a single character, and the code is 【WHERE title like & # 39;__Zhang San & # 39;】. More related free learning recommendation: mysql tutorial (video) mysql wildcard query Field method: First of all, let’s understand two concepts, one is an operator and the other is a wildcard. The operator like is the operator in the SQL statement. Its function is to indicate that the search pattern behind the SQL statement uses wildcards instead of direct Equality matches for comparison. Note: If no wildcard is used when using the like operator, the effect is consistent with the equal sign. SELECT id,title FROM table WHERE title like 'Zhang San'; This kind of writing is only It can match the record of Zhang San, but not the record like Zhang San is a good person. Wildcard % (percent sign), _ (underscore) is a wildcard, % means that any character appears any number of times (can be 0 times), _ means a single character, the user is as follows: SELECT id,title FROM table WHERE…
How does Mysql query the statement that starts with what character?
Sentence method of which character mysql query starts with: 1. Use wildcard query, the code is [SELECT * FROM `article` where title like 'positive%';]; 2. Use left function query, the code is [where left(title,1)]. What character does mysql query start with: 1: Use wildcards: SELECT * FROM `article` where title like ‘positive%’; 2: Use the left function: SELECT * FROM `article ` where left(title,1)='positive'; 3: Use the string interception function: SELECT * FROM `article` where substring(title,1,1)='正'; More related free learning recommendations:mysql tutorial(Video) The above is the detailed content of how Mysql queries the statement starting with what character. For more, please pay attention to other related articles on 1024programmer.com!
What are the main stages of the database design process?
The database design process includes six main stages: requirement analysis, conceptual structure design, logical structure design, physical structure design, database implementation, and database operation and maintenance. Database design refers to constructing an optimal database schema for a given application environment so that it can store data effectively and meet the application needs of various users. The design content of database design includes: requirements analysis, conceptual structure design, logical structure design, physical structure design, database implementation and database operation and maintenance. (Learning video sharing: mysql video tutorial) Related introduction: Database Design (Database Design) refers to a given application environment, structure The optimal database model, the establishment of database and its application system, so that it can store data effectively and meet the application requirements (information requirements and processing requirements) of various users. In the field of databases, various systems that use databases are often collectively referred to as database application systems. Database design principles: 1. One-to-one design principles In the software development process, it is necessary to follow the one-to-one relationship design principles to carry out data maintenance Work, by using this principle, we can minimize the occurrence of maintenance problems, ensure the smooth development of data maintenance work and reduce…
