分库中如何修改表中的字段长度和增加一列

#! /bin/shif [ $# -lt 1 ];thenecho "error.. need args"exitfiif [ "$1"x != "alter"x ];thenecho "usage alter_table.sh alter" #为了防止误执行脚本exitfimysql -uxxxx -pxxxx -e"alter table db_name.table_xxx modify column data varchar(1024);"for dbId in `seq 0 9` #假设由于十个库，库名为db_0 ~ db_9do    mysql -uxxxx -pxxxx -e"alter table db_${dbId}.table_name modify column data varchar(2048);"    mysql -uxxxx -pxxxx -e"alter table db_${dbId}.table_name add data int(10) unsigned default 0 after data_other;"done