Oracle 查询库中所有表信息

Oracle 查询库中所有表信息

查询所有表名：
select t.table_name from user_tables t;
查询所有字段名：
select t.column_name from user_col_comments t;
查询指定表的所有字段名：
select t.column_name from user_col_comments t where t.table_name = "BIZ_DICT_XB";
查询指定表的所有字段名和字段说明：
select t.column_name, t.column_name from user_col_comments t where t.table_name = "BIZ_DICT_XB";
查询所有表的表名和表说明：
select t.table_name,f.comments from user_tables t 
inner join user_tab_comments f on t.table_name = f.table_name;
查询模糊表名的表名和表说明：
select t.table_name from user_tables t where t.table_name like "BIZ_DICT%";
select t.table_name,f.comments from user_tables t 
inner join user_tab_comments f on t.table_name = f.table_name 
where t.table_name like "BIZ_DICT%";

--查询表的数据条数、表名、中文表名
select a.num_rows, a.TABLE_NAME, b.COMMENTS
from user_tables a, user_tab_comments b
WHERE a.TABLE_NAME = b.TABLE_NAME
order by TABLE_NAME;

原文链接 https://www.cnblogs.com/momoyan/p/9129169.html

Oracle日期时间范围查询

--字段为：字符串类型（char），长度为:10  
SELECT * FROM testdatetime t WHERE 1=1 AND t.createdate = "2011-07-01";  
SELECT * FROM testdatetime t WHERE 1=1 AND to_date(t.createdate,"yyyy-MM-dd") between to_date("2011-06-01","yyyy-MM-dd") and to_date("20110705","yyyymmdd") ;  
--字段为：字符串类型（char），长度为:20  
SELECT * FROM testdatetime t WHERE 1=1 AND t.usedate = "2011-07-01 10:00:00";  
SELECT * FROM testdatetime t WHERE 1=1 AND to_date(t.usedate,"yyyy-MM-dd HH24:MI:SS") 
between to_date("2011-07-01 12:00:00","yyyy-MM-dd HH24:MI:SS") and to_date("20110702 12:00:00","yyyymmdd HH24:MI:SS") ;  
--字段为：日期时间类型(date)
SELECT * FROM testdatetime t WHERE 1=1 AND t.startdate = to_date("2011-07-01","yyyy-MM-dd");
--字段为：字符串类
SELECT * FROM testdatetime t WHERE 1=1 AND to_char(t.startdate,"yyyy-MM-dd") = "2011-07-01";  

原文连接 https://www.cnblogs.com/james641/p/5805526.html

--获取现在时间
SELECT sysdate FROM dual;