在创建表和表结构的时候，如果想要小写需要在名称上面添加双引号，如果不添加oracle数据库会默认识别为大写

1.将表名和字段名改为大写

批量将表名变为大写

begin

for c in (select table_name tn from user_tables where table_name <> upper(table_name)) loop

begin

execute immediate 'alter table "'||c.tn||'" rename to '||c.tn;

exception

when others then

dbms_output.put_line(c.tn||'已存在');

end;

end loop;

end;

批量将空间内所有表的所有字段名变成大写  此方法可能导致溢出

begin

for t in (select table_name tn from user_tables) loop

begin

for c in (select column_name cn from user_tab_columns where table_name=t.tn) loop

begin

execute immediate 'alter table "'||t.tn||'" rename column "'||c.cn||'" to '||c.cn;

exception

when others then

dbms_output.put_line(t.tn||'.'||c.cn||'已经存在');

end;

end loop;

end;

end loop;

end;

将特点表PROPERTY_INFO的所有列名小写变大写

begin

for c in (select COLUMN_NAME cn from all_tab_columns where table_name='PROPERTY_INFO') loop

begin

execute immediate 'alter table PROPERTY_INFO rename column "'||c.cn||'" to '||c.cn;

exception

when others then

dbms_output.put_line('PROPERTY_INFO'||'.'||c.cn||'已经存在');

end;

end loop;

end;

2.将表名和字段名改为小写

①改表名为小写

begin

for c in (select table_name tn from user_tables where table_name <> lower(table_name)) loop

begin

execute immediate 'alter table '||c.tn||' rename to "'||lower(c.tn)||'"';

exception

when others then

dbms_output.put_line(c.tn||'已存在');

end;

end loop;

end;

②改字段名为小写

begin

for t in (select table_name tn from user_tables) loop

begin

for c in (select column_name cn from user_tab_columns where table_name=t.tn) loop

begin

execute immediate 'alter table '||t.tn||' rename column '||c.cn||' to "'||lower(c.cn)||'"';

exception

when others then

dbms_output.put_line(t.tn||'.'||c.cn||'已经存在');

end;

end loop;

end;

end loop;

end;

注：

1.如果字段和表名都要改为小写，先改字段，再改表。

2.如果表名获取字段名改为小写以后，要在查询语句中将表名和字段名都要加上双引号

例.

表名小写 ：select * from "department";

字段名小写：select "id" from "department";