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- mysql workbench alter table add column
- Adding new columns in MySQLWorkbench can be achieved through graphical interfaces or SQL statements. The operation steps of graphical interfaces are: find the target table → right-click to select "AlterTable" → switch to the "Columns" tab page → fill in the new column information → click "Apply" to confirm the changes; the SQL statement format is ALTERTABLE table name ADDCOLUMN column name data type constraints, such as ALTERTABLEusersADDCOLUMNageINTAFTERname; when adding columns, you need to pay attention to the field order, default value settings, performance impact, and index definition.
- Mysql Tutorial . Database 901 2025-06-26 08:01:10
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- Where does mysql workbench save connection information
- MySQLWorkbench stores connection information in the system configuration file. The specific path varies according to the operating system: 1. It is located in %APPDATA%\MySQL\Workbench\connections.xml in Windows system; 2. It is located in ~/Library/ApplicationSupport/MySQL/Workbench/connections.xml in macOS system; 3. It is usually located in ~/.mysql/workbench/connections.xml in Linux system or ~/.local/share/data/MySQL/Wor
- Mysql Tutorial . Database 441 2025-06-26 05:23:11
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- how to backup mysql database windows command line
- The correct way to back up a MySQL database under the Windows command line is to use the mysqldump tool. 1. First, confirm that the system environment variables contain the MySQL bin directory, or manually enter the directory to ensure that mysqldump is available; 2. Use the basic command format "mysqldump-u[user name]-p[database name]>[save path]\[file name].sql" to backup; 3. Add parameters such as --single-transaction, --routines, --events and --triggers to improve backup integrity and flexibility; 4. You can write .bat scripts and cooperate with the task planner to achieve automated backup.
- Mysql Tutorial . Database 604 2025-06-26 03:32:10
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- error 2002 can't connect to local mysql server on mac
- When "Error2002: Can't connecttolocalMySQLserverthroughsocket'/tmp/mysql.sock'" appears, 1. First confirm whether MySQL has been started, use brewserviceslist to check the status, and if stopped, use brewservicesstartmysql to start the service; 2. Check whether the connection method is correct, try to change the host from localhost to 127.0.0.1; 3. Confirm whether the path of the sock file is consistent, check whether /tmp/mysql.sock exists or check the path settings in the configuration file; 4.
- Mysql Tutorial . Database 514 2025-06-26 02:44:11
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- What's the difference between install options for MySQL Server
- The difference between MySQL installation options is functional integrity and applicable scenarios. 1. ServerOnly only installs servers, suitable for experienced users or production environment nodes; 2. ClientOnly only contains client tools, suitable for development and testing connections to remote databases; 3. Full/DeveloperDefault contains a complete set of tools, suitable for beginners to learn from; 4. Custom allows custom components, suitable for advanced users with specific needs. When choosing, you should decide based on the purpose to avoid repeated installation.
- Mysql Tutorial . Database 400 2025-06-25 23:33:11
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- How to import a CSV file using mysql workbench
- To import CSV files into MySQL database, you must first create a matching table structure, use the TableDataImportWizard tool, and pay attention to the file format and configuration. First, prepare the data table structure to ensure the consistent order and type of fields; second, select the file through the TableDataImportWizard of MySQLWorkbench and import it after field mapping; finally pay attention to using commas separated, skipping the title line, encoding it as UTF-8, and file path permission issues. If there is no ready-made table, it is recommended to analyze the CSV content first and then build the table.
- Mysql Tutorial . Database 306 2025-06-25 23:17:10
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- mysql tutorial about database normalization
- Soyou'retryingtounderstanddatabasenormalizationinMySQL?It’soneofthosetopicsthatsoundsmorecomplicatedthanitreallyis.Thecoreideaissimple:structureyourdatabasetoreduceredundancyandimprovedataintegrity.Thatmeansstoringe
- Mysql Tutorial . Database 353 2025-06-25 22:34:11
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- where is my.cnf file on mac
- MySQL configuration file my.cnf is usually located on macOS /etc/my.cnf, /usr/local/etc/my.cnf or ~/.my.cnf on macOS; 1. Confirm the location and check whether the startup command has --defaults-file parameters; 2. Use SHOWVARIABLESLIKE'config' to query the actual loading path; 3. Manually check whether the common path exists; if you cannot find the default template or new file, the restart service will take effect after adding the basic configuration; when modifying, you need to back up the original file, pay attention to syntax, permissions, restart and avoid multiple file conflicts.
- Mysql Tutorial . Database 141 2025-06-25 19:57:10
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- setup mysql on mac for local development
- Installing MySQL on Mac can be completed through Homebrew, running brewinstallmysql and starting the service; then executing mysql_secure_installation to set the root password, delete anonymous users, prohibit remote login, etc.; then creating a development database and exclusive users to improve security; when connecting, you can use command lines, GUI tools or application code to configure it, and pay attention to troubleshooting password errors, improper host configuration, etc. 1. Install MySQL and start the service; 2. Initialize security settings; 3. Create database and users; 4. Select the appropriate way to connect; 5. Solve common connection problems. The whole process is simple but you need to pay attention to permissions and configuration details.
- Mysql Tutorial . Database 569 2025-06-25 19:41:10
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- What are the transaction isolation levels in MySQL, and which is the default?
- MySQL's default transaction isolation level is RepeatableRead, which prevents dirty reads and non-repeatable reads through MVCC and gap locks, and avoids phantom reading in most cases; other major levels include read uncommitted (ReadUncommitted), allowing dirty reads but the fastest performance, 1. Read Committed (ReadCommitted) ensures that the submitted data is read but may encounter non-repeatable reads and phantom readings, 2. RepeatableRead default level ensures that multiple reads within the transaction are consistent, 3. Serialization (Serializable) the highest level, prevents other transactions from modifying data through locks, ensuring data integrity but sacrificing performance;
- Mysql Tutorial . Database 851 2025-06-23 15:05:11
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- What is the difference between DATABASE and SCHEMA in MySQL?
- InMySQL,thetermsdatabaseandschemaarenearlyinterchangeable,butcarrysubtlecontextualdifferences.2.Adatabaseisatop-levelcontainerfordataobjectsliketables,views,andprocedures,createdwithCREATEDATABASE.3.AschemainMySQLreferstoeitherthedatabaseitself—often
- Mysql Tutorial . Database 991 2025-06-22 16:45:11
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- How to check and change a table's storage engine?
- To view or modify the storage engine of MySQL tables, you can use the following methods: 1. Use SHOWCREATETABLEyour_table_name; view the storage engine of a single table; 2. Use SELECTTABLE_NAME,ENGINEFROMinformation_schema.TABLESWHERETABLE_SCHEMA='your_database_name'; batch view the storage engine of all tables in the database; 3. Use ALTERTABLEyour_table_nameENGINE=new_engine_name; modify the storage engine of tables, if changed to My
- Mysql Tutorial . Database 230 2025-06-21 13:41:10
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- Why does ORDER BY sometimes make a query slow?
- The main reasons for slowing SQL queries by adding ORDERBY include lack of indexes, excessive result sets, mixed use of JOIN and sorting, and temporary table processing problems. 1. The lack of index will cause the database to perform full sorting. Indexes should be created for the sorting sequence. Composite indexes should be used when WHERE is involved; 2. Large result sets increase the memory or disk I/O burden, and can limit the number of rows to be returned through LIMIT, avoid SELECT*, and use key set paging optimization; 3. The mixing of JOIN and ORDERBY may cause indexes to be invalid. It is necessary to ensure that the connection and sorting sequence have indexes, and try to adjust the JOIN order or get the primary key first and then associate; 4. The use of ORDERBY in subqueries may cause temporary tables to affect performance, and the sorting can be moved into subqueries and materialized derivatives.
- Mysql Tutorial . Database 783 2025-06-20 20:46:10
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- How can I tell if my query is using an index?
- You can check whether the query uses an index by looking at the execution plan. In most SQL systems, the query execution method can be analyzed using the EXPLAIN or EXPLAINANALYZE command; 1. If the output shows IndexScan or Usingindexcondition, it means that the index is used; 2. If SeqScan or type:ALL appears, the index is not used; 3. In MySQL, the Extra column shows Usingwhere; Usingindex means that the overlay index is used; 4. The key column is NULL, the index is not used; 5. The lower the rows value, the better, which means the number of rows that the optimizer expects to scan; 6. The composite index needs to be paid attention to
- Mysql Tutorial . Database 581 2025-06-20 13:33:10
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