Oracle常用查看表结构命令

获取表： 
select table_name from user_tables; //当前用户的表       
select table_name from all_tables; //所有用户的表   
select table_name from dba_tables; //包括系统表 
select table_name from dba_tables where owner='用户名' 
user_tables： 
table_name,tablespace_name,last_analyzed等 
dba_tables： 
ower,table_name,tablespace_name,last_analyzed等 
all_tables： 
ower,table_name,tablespace_name,last_analyzed等 
all_objects： 
ower,object_name,subobject_name,object_id,created,last_ddl_time,timestamp,status等 
获取表字段： 
select * from user_tab_columns where Table_Name='用户表'; 
select * from all_tab_columns where Table_Name='用户表'; 
select * from dba_tab_columns where Table_Name='用户表'; 
user_tab_columns： 
table_name,column_name,data_type,data_length,data_precision,data_scale,nullable,column_id等 
all_tab_columns ： 
ower,table_name,column_name,data_type,data_length,data_precision,data_scale,nullable,column_id等 
dba_tab_columns： 
ower,table_name,column_name,data_type,data_length,data_precision,data_scale,nullable,column_id等 
获取表注释： 
select * from user_tab_comments 
user_tab_comments：table_name,table_type,comments 
--相应的还有dba_tab_comments，all_tab_comments，这两个比user_tab_comments多了ower列。 
获取字段注释： 
select * from user_col_comments 
user_col_comments：table_name,column_name,comments