2020.10.1 第四次做業 mysql

mysql

1. 寫一個一鍵安裝 mariadb 數據庫腳本。（不許用王老師筆記上的，本身寫。）

#!/usr/bin/sh
# Author:  lujinkai 441757636@qq.com

# 二進制安裝mariadb10.5.5

export LANG=en_US.UTF-8
export LANGUAGE=en_US:en
Mem=`free -m | awk '/Mem:/{print $2}'`
mariadb_install_dir=/usr/local/mariadb
mariadb_data_dir=/data/mariadb
dbrootpwd=Lujinkai123_

[ ! -d "${mariadb_install_dir}" ] && mkdir -p ${mariadb_install_dir}
mkdir -p ${mariadb_data_dir};chown mysql.mysql -R ${mariadb_data_dir}

id -u mysql >/dev/null 2>&1
[ $? -ne 0 ] && useradd -r -M -s /sbin/nologin mysql

cd /usr/local/src
# wget https://mirrors.tuna.tsinghua.edu.cn/mariadb/mariadb-10.5.5/bintar-linux-x86_64/mariadb-10.5.5-linux-x86_64.tar.gz
tar zxvf ./mariadb-10.5.5-linux-x86_64.tar.gz
mv ./mariadb-10.5.5-linux-x86_64/* ${mariadb_install_dir}

if [ -d "${mariadb_install_dir}/support-files" ]; then
  echo "MariaDB installed successfully!"
else
  rm -rf ${mariadb_install_dir}
  echo "MariaDB install failed, Please contact the author!" && lsb_release -a
  kill -9 $$
fi

cd ${mariadb_install_dir}
sed -i 's@executing mysqld_safe@executing mysqld_safe\nexport LD_PRELOAD=/usr/local/lib/libjemalloc.so@' ./bin/mysqld_safe
sed -i "s@/usr/local/mysql@/usr/local/mariadb@g" ./bin/mysqld_safe
/bin/cp ./support-files/mysql.server /etc/init.d/mysqld
sed -i "s@^basedir=.*@basedir=${mariadb_install_dir}@" /etc/init.d/mysqld
sed -i "s@^datadir=.*@datadir=${mariadb_data_dir}@" /etc/init.d/mysqld
chmod +x /etc/init.d/mysqld
chkconfig --add mysqld; chkconfig mysqld on;

# my.cnf
  cat > /etc/my.cnf << EOF
[client]
port = 3306
socket = /tmp/mysql.sock
default-character-set = utf8mb4

[mysqld]
port = 3306
socket = /tmp/mysql.sock

basedir = ${mariadb_install_dir}
datadir = ${mariadb_data_dir}
pid-file = ${mariadb_data_dir}/mysql.pid
user = mysql
bind-address = 0.0.0.0
server-id = 1

init-connect = 'SET NAMES utf8mb4'
character-set-server = utf8mb4

skip-name-resolve
#skip-networking
back_log = 300

max_connections = 1000
max_connect_errors = 6000
open_files_limit = 65535
table_open_cache = 128
max_allowed_packet = 500M
binlog_cache_size = 1M
max_heap_table_size = 8M
tmp_table_size = 16M

read_buffer_size = 2M
read_rnd_buffer_size = 8M
sort_buffer_size = 8M
join_buffer_size = 8M
key_buffer_size = 4M

thread_cache_size = 8

query_cache_type = 1
query_cache_size = 8M
query_cache_limit = 2M

ft_min_word_len = 4

log_bin = mysql-bin
binlog_format = mixed
expire_logs_days = 7

log_error = ${mariadb_data_dir}/mysql-error.log
slow_query_log = 1
long_query_time = 1
slow_query_log_file = ${mariadb_data_dir}/mysql-slow.log

performance_schema = 0

#lower_case_table_names = 1

skip-external-locking

default_storage_engine = InnoDB
innodb_file_per_table = 1
innodb_open_files = 500
innodb_buffer_pool_size = 64M
innodb_write_io_threads = 4
innodb_read_io_threads = 4
innodb_thread_concurrency = 0
innodb_purge_threads = 1
innodb_flush_log_at_trx_commit = 2
innodb_log_buffer_size = 2M
innodb_log_file_size = 32M
innodb_log_files_in_group = 3
innodb_max_dirty_pages_pct = 90
innodb_lock_wait_timeout = 120

bulk_insert_buffer_size = 8M
myisam_sort_buffer_size = 8M
myisam_max_sort_file_size = 10G
myisam_repair_threads = 1

interactive_timeout = 28800
wait_timeout = 28800

[mysqldump]
quick
max_allowed_packet = 500M

[myisamchk]
key_buffer_size = 8M
sort_buffer_size = 8M
read_buffer = 4M
write_buffer = 4M
EOF

sed -i "s@max_connections.*@max_connections = $((${Mem}/3))@" /etc/my.cnf
if [ ${Mem} -gt 1500 -a ${Mem} -le 2500 ]; then
  sed -i 's@^thread_cache_size.*@thread_cache_size = 16@' /etc/my.cnf
  sed -i 's@^query_cache_size.*@query_cache_size = 16M@' /etc/my.cnf
  sed -i 's@^myisam_sort_buffer_size.*@myisam_sort_buffer_size = 16M@' /etc/my.cnf
  sed -i 's@^key_buffer_size.*@key_buffer_size = 16M@' /etc/my.cnf
  sed -i 's@^innodb_buffer_pool_size.*@innodb_buffer_pool_size = 128M@' /etc/my.cnf
  sed -i 's@^tmp_table_size.*@tmp_table_size = 32M@' /etc/my.cnf
  sed -i 's@^table_open_cache.*@table_open_cache = 256@' /etc/my.cnf
elif [ ${Mem} -gt 2500 -a ${Mem} -le 3500 ]; then
  sed -i 's@^thread_cache_size.*@thread_cache_size = 32@' /etc/my.cnf
  sed -i 's@^query_cache_size.*@query_cache_size = 32M@' /etc/my.cnf
  sed -i 's@^myisam_sort_buffer_size.*@myisam_sort_buffer_size = 32M@' /etc/my.cnf
  sed -i 's@^key_buffer_size.*@key_buffer_size = 64M@' /etc/my.cnf
  sed -i 's@^innodb_buffer_pool_size.*@innodb_buffer_pool_size = 512M@' /etc/my.cnf
  sed -i 's@^tmp_table_size.*@tmp_table_size = 64M@' /etc/my.cnf
  sed -i 's@^table_open_cache.*@table_open_cache = 512@' /etc/my.cnf
elif [ ${Mem} -gt 3500 ]; then
  sed -i 's@^thread_cache_size.*@thread_cache_size = 64@' /etc/my.cnf
  sed -i 's@^query_cache_size.*@query_cache_size = 64M@' /etc/my.cnf
  sed -i 's@^myisam_sort_buffer_size.*@myisam_sort_buffer_size = 64M@' /etc/my.cnf
  sed -i 's@^key_buffer_size.*@key_buffer_size = 256M@' /etc/my.cnf
  sed -i 's@^innodb_buffer_pool_size.*@innodb_buffer_pool_size = 1024M@' /etc/my.cnf
  sed -i 's@^tmp_table_size.*@tmp_table_size = 128M@' /etc/my.cnf
  sed -i 's@^table_open_cache.*@table_open_cache = 1024@' /etc/my.cnf
fi

${mariadb_install_dir}/scripts/mysql_install_db --user=mysql --basedir=${mariadb_install_dir} --datadir=${mariadb_data_dir}

[ -d "/etc/mysql" ] && /bin/mv /etc/mysql{,_bk}
service mysqld start

[ -z "$(grep ^'export PATH=' /etc/profile)" ] && echo "export PATH=${mariadb_install_dir}/bin:\$PATH" >> /etc/profile
[ -n "$(grep ^'export PATH=' /etc/profile)" -a -z "$(grep ${mariadb_install_dir} /etc/profile)" ] && sed -i "s@^export PATH=\(.*\)@export PATH=${mariadb_install_dir}/bin:\1@" /etc/profile
. /etc/profile

${mariadb_install_dir}/bin/mysql -e "grant all privileges on *.* to root@'127.0.0.1' identified by \"${dbrootpwd}\" with grant option;"
${mariadb_install_dir}/bin/mysql -e "grant all privileges on *.* to root@'localhost' identified by \"${dbrootpwd}\" with grant option;"
${mariadb_install_dir}/bin/mysql -uroot -p${dbrootpwd} -e "delete from mysql.user where Password='';"
${mariadb_install_dir}/bin/mysql -uroot -p${dbrootpwd} -e "delete from mysql.db where User='';"
${mariadb_install_dir}/bin/mysql -uroot -p${dbrootpwd} -e "delete from mysql.proxies_priv where Host!='localhost';"
${mariadb_install_dir}/bin/mysql -uroot -p${dbrootpwd} -e "drop database test;"
${mariadb_install_dir}/bin/mysql -uroot -p${dbrootpwd} -e "reset master;"
rm -rf /etc/ld.so.conf.d/{mysql,mariadb,percona,alisql}*.conf
echo "${mariadb_install_dir}/lib" > /etc/ld.so.conf.d/mariadb.conf
ldconfig
service mysqld stop

2. 簡述Event 事件介紹以及它的優缺點

佔位。。。放假回來再寫

3. 在 students 表中，查詢年齡大於25歲，且爲男性的同窗的名字和年齡:

佔位。。。放假回來再寫

2. 在 students 表中，以 ClassID 爲分組依據，查詢顯示每組的平均年齡

佔位。。。放假回來再寫

3. 顯示第2題中平均年齡大於30的分組及平均年齡

佔位。。。放假回來再寫