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MySQL-8.0.15 - SELECT 语句 SELECT 查询语句 查询1USE sql_store; SELECT * FROM customers -- WHERE customer_id = 1 ORDER BY first_name;查询 2SELECT last_name, first_name, points, points * 10 + 100 FROM customers;练习-- Return all the products -- name -- unit price -- new price (unit price * 1.1) SELECT name, unit_price, unit_price * 1.1 AS new_price FROM products; -
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SQL - 系统数据库 SQL Server2012系统数据库SQL系统数据库在安装SQL Server实例时由系统默认创建：mastertempdbmodelmsdbresourcedistributionmaster数据库master 数据库是主系统数据库。丢失该库，SQL Server将无法启动，master数据库包含SQL Server实例中所有对象的重要信息；数据库AlwaysOn数据库镜像配置登录资源调控端点(Endpoints)如果想获取某个SQL Server实例中全部数据库清单，可以执行以下查询；SELECT * FROM sys.master_filestempdb 数据库tempdb数据库是全局性的，服务于由内部进程创建的临时对旬，这些进程用于运行SQL Server或者用于运行由用户或应用程序 所创建的临时对象。这些临时对象包括临时表与存储过程、表变量、全局临时表以及游标等。除了临时对象，tempdb中还存储了有关已提交读取(read-committed)或快照分离事务、联机索引操作以及AFTER触发器的行版本信息。虽然也可以在tempdb中创建对象，但却无法在永久数据库那样使用这些对象。model数据库model数据库，它是在SQL Server实例中创建的全部数据库的模型。在每次创建数据库时，该库被用作模板。例如：当需要一张特定的表，该表存在于SQL Server实例中所有的数据库，那么就可以在model数据库中创建此表，以后每一次创建数据库时，都将包含这张表。注意：如果没有model数据库或者该库已脱机，则tempdb数据库也无法创建，原因是当每一次SQL Server重启时，临时库都重新生成，而实例中所有的数据库都需要用到model数据库作为模板。tempdb也不例外，因此缺少model数据库则tempdb也无法创建。msdb 数据库msdb 数据库主要用作 SQL Server代理(Agent)的支撑后台，在创建或安排一个SQL Server代理作业时,该作业中的元数据就存储在此数据库中。除SQL Server代理的数据外，msdb中还存储下列组件的信息:服务代理(Service brokers)警报日志传送ssis包实用工具控制点（UCP）数据库邮件维护计划
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MySQL 8.0 编译安装 MySQL 8.0编译安装- 创建用户 [root@localhost]# groupadd mysql [root@localhost]# useradd -s /sbin/nologin -M -g mysql mysql [root@localhost soft]# tar zxf mysql-boost-8.0.25.tar.gz [root@localhost soft]# cd mysql-8.0.25/ [root@localhost mysql-8.0.25]# cmake .. -DCMAKE_INSTALL_PREFIX=/usr/local/mysql \ -DSYSCONFDIR=/usr/local/mysql/etc \ -DWITH_MYISAM_STORAGE_ENGINE=1 \ -DWITH_INNOBASE_STORAGE_ENGINE=1 \ -DWITH_PARTITION_STORAGE_ENGINE=1 \ -DWITH_FEDERATED_STORAGE_ENGINE=1 \ -DEXTRA_CHARSETS=all \ -DDEFAULT_CHARSET=utf8mb4 \ -DDEFAULT_COLLATION=utf8mb4_general_ci \ -DWITH_EMBEDDED_SERVER=1 \ -DENABLED_LOCAL_INFILE=1 \ -DWITH_BOOST=/opt/soft/mysql-8.0.25/boostmy.cnf[client] #password = your_password port = 3306 socket = /tmp/mysql.sock [mysqld] port = 3306 socket = /tmp/mysql.sock datadir = /usr/local/mysql/data skip-external-locking key_buffer_size = 16M max_allowed_packet = 1M table_open_cache = 64 sort_buffer_size = 512K net_buffer_length = 8K read_buffer_size = 256K read_rnd_buffer_size = 512K myisam_sort_buffer_size = 8M thread_cache_size = 8 tmp_table_size = 16M performance_schema_max_table_instances = 500 explicit_defaults_for_timestamp = true #skip-networking max_connections = 500 max_connect_errors = 100 open_files_limit = 65535 default_authentication_plugin = mysql_native_password log-bin=mysql-bin binlog_format=mixed server-id = 1 binlog_expire_logs_seconds = 864000 early-plugin-load = "" default_storage_engine = InnoDB innodb_file_per_table = 1 innodb_data_home_dir = /usr/local/mysql/data innodb_data_file_path = ibdata1:10M:autoextend innodb_log_group_home_dir = /usr/local/mysql/data innodb_buffer_pool_size = 16M innodb_log_file_size = 5M innodb_log_buffer_size = 8M innodb_flush_log_at_trx_commit = 1 innodb_lock_wait_timeout = 50 [mysqldump] quick max_allowed_packet = 16M [mysql] no-auto-rehash [myisamchk] key_buffer_size = 20M sort_buffer_size = 20M read_buffer_size = 2M write_buffer_size = 2M [mysqlhotcopy] interactive-timeout设置开机启动[root@localhost]# chown -R mysql:mysql /usr/local/mysql/data [root@localhost]# /usr/local/mysql/bin/mysqld --initialize-insecure --basedir=/usr/local/mysql --datadir=/usr/local/mysql/data --user=mysql [root@localhost]# chgrp -R mysql /usr/local/mysql/. [root@localhost]# cp support-files/mysql.server /etc/init.d/mysql > # cp /init.d/mysql.service /etc/systemd/system/mysql.service [root@localhost]# chmod 755 /etc/init.d/mysql [root@localhost]# cat > /etc/ld.so.conf.d/mysql.conf<<EOF /usr/local/mysql/lib /usr/local/lib EOF [root@localhost]# ldconfig [root@localhost]# ln -sf /usr/local/mysql/lib/mysql /usr/lib/mysql [root@localhost]# ln -sf /usr/local/mysql/include/mysql /usr/include/mysql设置密码SET PASSWORD FOR 'root'@'localhost' = 'password'; 或 UPDATE mysql.user SET Password=PASSWORD('${DB_Root_Password}') WHERE User='root';
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MySQL 5.7 编译安装 MySQL 5.7 编译安装安装依赖yum install ncurses ncurses-devel -y[root@localhost]# groupadd mysql [root@localhost]# useradd -s /sbin/nologin -M -g mysql mysql [root@localhost soft]# tar zxf mysql-boost-5.7.34.tar.gz [root@localhost soft]# cd mysql-5.7.34/ [root@localhost mysql-5.7.34]# cmake -DCMAKE_INSTALL_PREFIX=/usr/local/mysql \ -DSYSCONFDIR=/usr/local/mysql/etc \ -DWITH_MYISAM_STORAGE_ENGINE=1 \ -DWITH_INNOBASE_STORAGE_ENGINE=1 \ -DWITH_PARTITION_STORAGE_ENGINE=1 \ -DWITH_FEDERATED_STORAGE_ENGINE=1 \ -DEXTRA_CHARSETS=all \ -DDEFAULT_CHARSET=utf8mb4 \ -DDEFAULT_COLLATION=utf8mb4_general_ci \ -DWITH_EMBEDDED_SERVER=1 -DENABLED_LOCAL_INFILE=1 \ -DWITH_BOOST=/opt/soft/mysql-5.7.34/boostmy.cnf[client] #password = your_password port = 3306 socket = /tmp/mysql.sock [mysqld] port = 3306 socket = /tmp/mysql.sock datadir = /usr/local/mysql/data skip-external-locking key_buffer_size = 16M max_allowed_packet = 1M table_open_cache = 64 sort_buffer_size = 512K net_buffer_length = 8K read_buffer_size = 256K read_rnd_buffer_size = 512K myisam_sort_buffer_size = 8M thread_cache_size = 8 query_cache_size = 8M tmp_table_size = 16M performance_schema_max_table_instances = 500 explicit_defaults_for_timestamp = true #skip-networking max_connections = 500 max_connect_errors = 100 open_files_limit = 65535 log-bin=mysql-bin binlog_format=mixed server-id = 1 expire_logs_days = 10 early-plugin-load = "" default_storage_engine = InnoDB innodb_file_per_table = 1 innodb_data_home_dir = /usr/local/mysql/data innodb_data_file_path = ibdata1:10M:autoextend innodb_log_group_home_dir = /usr/local/mysql/data innodb_buffer_pool_size = 16M innodb_log_file_size = 5M innodb_log_buffer_size = 8M innodb_flush_log_at_trx_commit = 1 innodb_lock_wait_timeout = 50 [mysqldump] quick max_allowed_packet = 16M [mysql] no-auto-rehash [myisamchk] key_buffer_size = 20M sort_buffer_size = 20M read_buffer_size = 2M write_buffer_size = 2M [mysqlhotcopy] interactive-timeout 初始化数据库--initialize-insecure 密码为空--initialize 生成默认密码[root@local]# chown -R mysql.mysql /usr/local/mysql/data [root@local]# /usr/local/mysql/bin/mysqld --initialize-insecure --basedir=/usr/local/mysql --datadir=/usr/local/mysql/data --user=mysql [root@local]# chgrp -R mysql /usr/local/mysql/.设置开机启动[root@local]# cp /usr/local/mysql/support-files/mysql.server /etc/init.d/mysqld [root@local]# chmod 755 /etc/init.d/mysqld [root@local]# ln -sf /usr/local/mysql/bin/mysql /usr/bin/mysql [root@local]# ln -sf /usr/local/mysql/bin/mysqldump /usr/bin/mysqldump [root@local]# ln -sf /usr/local/mysql/bin/myisamchk /usr/bin/myisamchk [root@local]# ln -sf /usr/local/mysql/bin/mysqld_safe /usr/bin/mysqld_safe [root@local]# ln -sf /usr/local/mysql/bin/mysqlcheck /usr/bin/mysqlcheck设置root密码[root@local]# mysql mysql> SET PASSWORD FOR 'root'@'localhost' = PASSWORD('${DB_Root_Password}');内存小于2Gkey_buffer_size = 32M table_open_cache = 128 sort_buffer_size = 768K read_buffer_size = 768K myisam_sort_buffer_size = 8M thread_cache_size = 16 query_cache_size = 16M tmp_table_size = 32M innodb_buffer_pool_size = 128M innodb_log_file_size = 32M performance_schema_max_table_instances = 1000内存 2G-4Gkey_buffer_size = 64M table_open_cache = 256 sort_buffer_size = 1M read_buffer_size = 1M myisam_sort_buffer_size = 16M thread_cache_size = 32 query_cache_size = 32M tmp_table_size = 64M innodb_buffer_pool_size = 256M innodb_log_file_size = 64M performance_schema_max_table_instances = 2000内存 4G-8Gkey_buffer_size = 128M table_open_cache = 512 sort_buffer_size = 2M read_buffer_size = 2M myisam_sort_buffer_size = 32M thread_cache_size = 64 query_cache_size = 64M tmp_table_size = 64M innodb_buffer_pool_size = 512M innodb_log_file_size = 128M performance_schema_max_table_instances = 4000内存 8G-16Gkey_buffer_size = 256M table_open_cache = 1024 sort_buffer_size = 4M read_buffer_size = 4M myisam_sort_buffer_size = 64M thread_cache_size = 128 query_cache_size = 128M tmp_table_size = 128M innodb_buffer_pool_size = 1024M innodb_log_file_size = 256M performance_schema_max_table_instances = 6000-内存 16G-32Gkey_buffer_size = 512M table_open_cache = 2048 sort_buffer_size = 8M read_buffer_size = 8M myisam_sort_buffer_size = 128M thread_cache_size = 256 query_cache_size = 256M tmp_table_size = 256M innodb_buffer_pool_size = 2048M innodb_log_file_size = 512M performance_schema_max_table_instances = 8000内存 > 32gkey_buffer_size = 1024M table_open_cache = 4096 sort_buffer_size = 16M read_buffer_size = 16M myisam_sort_buffer_size = 256M thread_cache_size = 512 query_cache_size = 512M tmp_table_size = 512M innodb_buffer_pool_size = 4096M innodb_log_file_size = 1024M performance_schema_max_table_instances = 10000
