查每张表中有多少条记录 SELECT table_name,num_rows FROM user_tables order by num_rows desc; https://www.cnblogs.com/xzhg/p/6473011.html 查一张表中不同时间段分别有多少条记录: select ttime, count(ttime) from VOLTE_GT_CELL_ANA_BASEDAY group by ttime; select ttime,count(ttime) from V
1.查看一个表所占的空间大小:SELECT bytes/1024/1024 ||'MB' TABLE_SIZE ,u.* FROM USER_SEGMENTS U WHERE U.SEGMENT_NAME='JK_TEST';2.查看一个表空间所占的实际大小:SELECT SUM(BYTES) / 1024 / 1024 ||'MB' FROM USER_SEGMENTS U WHERE TABLESPACE_NAME = 'DATA01';3.查看一个表空间对应的数据文件:SELECT *
Oracle表操作 --主键,复合主键 create table example (id number primary key, name varchar2(20)); create table example1 (id number, name varchar2(20),primary key(id)); create table example2 (id number, name varchar2(20)); ALTER TABLE example2 ADD PRIMARY KEY (ID)
--删除 drop table dianfei; --创建表 create table dianfei ( uon ) not null, mmonth ) not null, ddf ,) not null, djftime date not null, djfzt ) not null, dsyjf date not null ); --注释 comment on table dianfei is '电表'; comment on column dianfei.uon is '用户编号(从键
表是否存在: select count(*) from user_tables where table_name = #{tablename} 包含某个字段的表 select * from user_tab_columns where UPPER(column_name)='CREATE_TIME' 特定表是否包含字段 select * from user_tab_columns where UPPER(column_name)='CREATE_TIME' AND TABLE_NAME = 'S
注意点:1.被update主表一定要加上过滤条件.2.查询出来更新结果集,同时也要作为被更新主表的条件,作为同步大家都是更新这部分数据.update student stu set (stu.name,stu.sex) = (select bak.name,bak.sex from student_bak bak where bak.id = stu.id and stu.age = 20 ) where exists (select 1 from student_bak bak where b
1.Oracle查询数据库中所有表的记录数,但是有可能不准建议用第二种方式进行查询 select t.table_name,t.num_rows from user_tables t 2.创建oracle函数,通过函数中查询词表记录数显示当前记录数 create or replace function count_rows(table_name in varchar2, owner in varchar2 default null) return number authid current_us
Oracle查询库中记录数大于2千万的所有表 假如当前用户拥有select any table权限,则可以使用下列sql语句: select table_name, num_rows from dba_tables t where t.owner = upper('hr') and num_rows > 20000000; 或 select table_name, num_rows from all_tables t where t.owner = upper('hr') and num_row