mysql8基础 use 更改要使用的数据库

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  •        OS : Ubuntu 18.04.1 LTS
  •        DBMS : mysql 8.0.12
  •        blog : blog.csdn.net/shiwanwu
  •  typesetting : Markdown

数据,数据,命根就在数据 ! 操作数据库时,一定要谨慎小心。师万物 的代码看看就好,要有自己的判断。遇到抉择,要不耻上下问。

example

stu@Ubuntu:~$ mysql -u root -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 18
Server version: 8.0.12 MySQL Community Server - GPL

Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
4 rows in set (0.00 sec)

mysql> use sys;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> show tables;
+-----------------------------------------------+
| Tables_in_sys                                 |
+-----------------------------------------------+
| host_summary                                  |
| host_summary_by_file_io                       |
| host_summary_by_file_io_type                  |
| host_summary_by_stages                        |
| host_summary_by_statement_latency             |
| host_summary_by_statement_type                |
| innodb_buffer_stats_by_schema                 |
| innodb_buffer_stats_by_table                  |
| innodb_lock_waits                             |
| io_by_thread_by_latency                       |
| io_global_by_file_by_bytes                    |
| io_global_by_file_by_latency                  |
| io_global_by_wait_by_bytes                    |
| io_global_by_wait_by_latency                  |
| latest_file_io                                |
| memory_by_host_by_current_bytes               |
| memory_by_thread_by_current_bytes             |
| memory_by_user_by_current_bytes               |
| memory_global_by_current_bytes                |
| memory_global_total                           |
| metrics                                       |
| processlist                                   |
| ps_check_lost_instrumentation                 |
| schema_auto_increment_columns                 |
| schema_index_statistics                       |
| schema_object_overview                        |
| schema_redundant_indexes                      |
| schema_table_lock_waits                       |
| schema_table_statistics                       |
| schema_table_statistics_with_buffer           |
| schema_tables_with_full_table_scans           |
| schema_unused_indexes                         |
| session                                       |
| session_ssl_status                            |
| statement_analysis                            |
| statements_with_errors_or_warnings            |
| statements_with_full_table_scans              |
| statements_with_runtimes_in_95th_percentile   |
| statements_with_sorting                       |
| statements_with_temp_tables                   |
| sys_config                                    |
| user_summary                                  |
| user_summary_by_file_io                       |
| user_summary_by_file_io_type                  |
| user_summary_by_stages                        |
| user_summary_by_statement_latency             |
| user_summary_by_statement_type                |
| version                                       |
| wait_classes_global_by_avg_latency            |
| wait_classes_global_by_latency                |
| waits_by_host_by_latency                      |
| waits_by_user_by_latency                      |
| waits_global_by_latency                       |
| x$host_summary                                |
| x$host_summary_by_file_io                     |
| x$host_summary_by_file_io_type                |
| x$host_summary_by_stages                      |
| x$host_summary_by_statement_latency           |
| x$host_summary_by_statement_type              |
| x$innodb_buffer_stats_by_schema               |
| x$innodb_buffer_stats_by_table                |
| x$innodb_lock_waits                           |
| x$io_by_thread_by_latency                     |
| x$io_global_by_file_by_bytes                  |
| x$io_global_by_file_by_latency                |
| x$io_global_by_wait_by_bytes                  |
| x$io_global_by_wait_by_latency                |
| x$latest_file_io                              |
| x$memory_by_host_by_current_bytes             |
| x$memory_by_thread_by_current_bytes           |
| x$memory_by_user_by_current_bytes             |
| x$memory_global_by_current_bytes              |
| x$memory_global_total                         |
| x$processlist                                 |
| x$ps_digest_95th_percentile_by_avg_us         |
| x$ps_digest_avg_latency_distribution          |
| x$ps_schema_table_statistics_io               |
| x$schema_flattened_keys                       |
| x$schema_index_statistics                     |
| x$schema_table_lock_waits                     |
| x$schema_table_statistics                     |
| x$schema_table_statistics_with_buffer         |
| x$schema_tables_with_full_table_scans         |
| x$session                                     |
| x$statement_analysis                          |
| x$statements_with_errors_or_warnings          |
| x$statements_with_full_table_scans            |
| x$statements_with_runtimes_in_95th_percentile |
| x$statements_with_sorting                     |
| x$statements_with_temp_tables                 |
| x$user_summary                                |
| x$user_summary_by_file_io                     |
| x$user_summary_by_file_io_type                |
| x$user_summary_by_stages                      |
| x$user_summary_by_statement_latency           |
| x$user_summary_by_statement_type              |
| x$wait_classes_global_by_avg_latency          |
| x$wait_classes_global_by_latency              |
| x$waits_by_host_by_latency                    |
| x$waits_by_user_by_latency                    |
| x$waits_global_by_latency                     |
+-----------------------------------------------+
101 rows in set (0.01 sec)

mysql> use performance_schema;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> show tables;
+------------------------------------------------------+
| Tables_in_performance_schema                         |
+------------------------------------------------------+
| accounts                                             |
| cond_instances                                       |
| data_lock_waits                                      |
| data_locks                                           |
| events_errors_summary_by_account_by_error            |
| events_errors_summary_by_host_by_error               |
| events_errors_summary_by_thread_by_error             |
| events_errors_summary_by_user_by_error               |
| events_errors_summary_global_by_error                |
| events_stages_current                                |
| events_stages_history                                |
| events_stages_history_long                           |
| events_stages_summary_by_account_by_event_name       |
| events_stages_summary_by_host_by_event_name          |
| events_stages_summary_by_thread_by_event_name        |
| events_stages_summary_by_user_by_event_name          |
| events_stages_summary_global_by_event_name           |
| events_statements_current                            |
| events_statements_histogram_by_digest                |
| events_statements_histogram_global                   |
| events_statements_history                            |
| events_statements_history_long                       |
| events_statements_summary_by_account_by_event_name   |
| events_statements_summary_by_digest                  |
| events_statements_summary_by_host_by_event_name      |
| events_statements_summary_by_program                 |
| events_statements_summary_by_thread_by_event_name    |
| events_statements_summary_by_user_by_event_name      |
| events_statements_summary_global_by_event_name       |
| events_transactions_current                          |
| events_transactions_history                          |
| events_transactions_history_long                     |
| events_transactions_summary_by_account_by_event_name |
| events_transactions_summary_by_host_by_event_name    |
| events_transactions_summary_by_thread_by_event_name  |
| events_transactions_summary_by_user_by_event_name    |
| events_transactions_summary_global_by_event_name     |
| events_waits_current                                 |
| events_waits_history                                 |
| events_waits_history_long                            |
| events_waits_summary_by_account_by_event_name        |
| events_waits_summary_by_host_by_event_name           |
| events_waits_summary_by_instance                     |
| events_waits_summary_by_thread_by_event_name         |
| events_waits_summary_by_user_by_event_name           |
| events_waits_summary_global_by_event_name            |
| file_instances                                       |
| file_summary_by_event_name                           |
| file_summary_by_instance                             |
| global_status                                        |
| global_variables                                     |
| host_cache                                           |
| hosts                                                |
| log_status                                           |
| memory_summary_by_account_by_event_name              |
| memory_summary_by_host_by_event_name                 |
| memory_summary_by_thread_by_event_name               |
| memory_summary_by_user_by_event_name                 |
| memory_summary_global_by_event_name                  |
| metadata_locks                                       |
| mutex_instances                                      |
| objects_summary_global_by_type                       |
| performance_timers                                   |
| persisted_variables                                  |
| prepared_statements_instances                        |
| replication_applier_configuration                    |
| replication_applier_filters                          |
| replication_applier_global_filters                   |
| replication_applier_status                           |
| replication_applier_status_by_coordinator            |
| replication_applier_status_by_worker                 |
| replication_connection_configuration                 |
| replication_connection_status                        |
| replication_group_member_stats                       |
| replication_group_members                            |
| rwlock_instances                                     |
| session_account_connect_attrs                        |
| session_connect_attrs                                |
| session_status                                       |
| session_variables                                    |
| setup_actors                                         |
| setup_consumers                                      |
| setup_instruments                                    |
| setup_objects                                        |
| setup_threads                                        |
| socket_instances                                     |
| socket_summary_by_event_name                         |
| socket_summary_by_instance                           |
| status_by_account                                    |
| status_by_host                                       |
| status_by_thread                                     |
| status_by_user                                       |
| table_handles                                        |
| table_io_waits_summary_by_index_usage                |
| table_io_waits_summary_by_table                      |
| table_lock_waits_summary_by_table                    |
| threads                                              |
| user_defined_functions                               |
| user_variables_by_thread                             |
| users                                                |
| variables_by_thread                                  |
| variables_info                                       |
+------------------------------------------------------+
102 rows in set (0.00 sec)

mysql> exit
Bye
stu@Ubuntu:~$ 

resource


MySQL是关系型数据库管理系统,目前是开源的(2019-02)。
明确权限,恰当地选择引擎与字符集等,规范命名。
MariaDB,Redis,MongoDB,PostgreSQL,Hive,HBase等,多作了解,拓宽心量。
Workbench,phpMyAdmin,Navicat等图形化管理工具,豫兮若冬涉川。

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转载自blog.csdn.net/shiwanwu/article/details/88084596