Q004Mysql批量修改字段注释

MYSQL本身没有这种批量的命令。不过你可以自己生成 alter table t modify  的脚本，一次性把所有需要修改的列的注释更新。

先利用sql进行表格的信息查询来制作执行语句（网上轮子）：

SELECT CONCAT(
               \'alter table \',
               table_schema, \'.\', table_name,
               \' modify column \', column_name, \' \', column_type, \' \',
               IF(is_nullable = \'YES\', \' \', \'not null \'),
               IF(column_default IS NULL, \'\',
                  IF(
                              data_type IN (\'char\', \'varchar\')
                              OR
                              data_type IN (\'date\', \'datetime\', \'timestamp\') AND column_default != \'CURRENT_TIMESTAMP\',
                              CONCAT(\' default \'\'\', column_default, \'\'\'\'),
                              CONCAT(\' default \', column_default)
                      )
                   ),
               IF(extra IS NULL OR extra = \'\', \'\', CONCAT(\' \', extra)),
               \' comment \'\'\', column_comment, \'\'\';\'
           ) \'组合语句\'
  FROM information_schema.columns
 WHERE table_schema = \'study\'              -- 库名
   AND table_name = \'jsl_bond_info_temp_t\' -- 表名

--------------------------------------------------------------------------

alter table study.jsl_bond_info_temp_t modify column put_price decimal(15,3) comment \'\';
alter table study.jsl_bond_info_temp_t modify column turnover_rt decimal(15,3) comment \'\';
alter table study.jsl_bond_info_temp_t modify column curr_iss_amt decimal(15,3) comment \'\';
alter table study.jsl_bond_info_temp_t modify column rating_cd varchar(10) comment \'\';
alter table study.jsl_bond_info_temp_t modify column issuer_rating_cd varchar(10) comment \'\';
alter table study.jsl_bond_info_temp_t modify column guarantor varchar(240) comment \'\';
alter table study.jsl_bond_info_temp_t modify column repo_cd varchar(30) comment \'\';
alter table study.jsl_bond_info_temp_t modify column sincrease_rt varchar(10) comment \'\';
alter table study.jsl_bond_info_temp_t modify column premium_rt varchar(10) comment \'\';
alter table study.jsl_bond_info_temp_t modify column year_left decimal(15,3) comment \'\';
alter table study.jsl_bond_info_temp_t modify column ytm_rt varchar(10) comment \'\';
alter table study.jsl_bond_info_temp_t modify column increase_rt varchar(10) comment \'\';
alter table study.jsl_bond_info_temp_t modify column volume decimal(15,3) comment \'\';
alter table study.jsl_bond_info_temp_t modify column short_maturity_dt date comment \'\';
alter table study.jsl_bond_info_temp_t modify column dblow decimal(15,3) comment \'\';
alter table study.jsl_bond_info_temp_t modify column force_redeem_price decimal(15,3) comment \'\';
alter table study.jsl_bond_info_temp_t modify column put_convert_price varchar(20) comment \'\';
alter table study.jsl_bond_info_temp_t modify column convert_amt_ratio varchar(10) comment \'\';

 

自己再加注释。。。。