學習shell腳本編程的一次實踐，通過shell腳本生成數據庫的markdown文檔，代碼如下：

 HOST=xxxxxx
 PORT=xxxx
 USER="xxxxx"
 PASSWORD="xxxxxx"
 DATABASE_PREFIX="xxxxxx"
  
 QUERY_DATABASE="select distinct TABLE_SCHEMA from information_schema.TABLES where TABLE_TYPE='BASE TABLE'"
 databaseList=$(mysql -h ${HOST} -u ${USER} -p${PASSWORD} -e "${QUERY_DATABASE}")

 for database in ${databaseList}
 do
     if [[ ${database} == *${DATABASE_PREFIX}* ]]
     then
         echo "Start ${database}"
         echo "### ${database}" >> test.md
         queryTable="select  distinct TABLE_NAME from information_schema.COLUMNS where TABLE_SCHEMA='${database}'"
         tableList=$(mysql -h ${HOST} -u ${USER} -p${PASSWORD} -N -e "${queryTable}")
         for table in ${tableList}
         do
                
             if [ $(grep -c "#### ${table%_*}_0" test.md) -ne '0' ] 
             then
                 continue
             fi
             

             echo "Start print table:${table}"
             echo "#### ${table}" >> test.md
             echo "名稱 | 類型 | 是否可為空 | Key | 說明" >> test.md
             echo "--|--|--|--|--" >> test.md
             queryCloumns="select COLUMN_NAME, replace(COLUMN_TYPE,' ',''),IS_NULLABLE,CONCAT(COLUMN_KEY,'+++++++++'),CONCAT(replace(COLUMN_COMMENT,' ',''),'+++++++++') from information_schema.COLUMNS where TABLE_NAME='${table}' and TABLE_SCHEMA='${database}' order by ORDINAL_POSITION"

             columnList=$(mysql -h ${HOST} -u ${USER} -p${PASSWORD} -N -e "${queryCloumns}")
             count=0
             row=""
              for column in ${columnList}
              do
                  row="${row} ${column} | "

                  let count++
                  if [[ ${count} == 5 ]]
                  then
                      echo ${row} >> test.md
                      count=0
                      row=""
                  fi
              done
          done
 
      fi
  done
 

使用shell腳本生成數據庫markdown文檔