-
编辑 删除
$1,890.55格式的显示
$1,890.55
-
编辑 删除
关于外键约束
FOREIGN KEY REFERENCES
-
编辑 删除
关于中文日期
SQL> SELECT next_day(sysdate,'星期五') 2 FROM DUAL 3 ;NEXT_DAY(SYSDATE,'星期五')--------------------------2018/3/9 10:55:59SQL> SELECT TO_DATE('01-1月-2007') FROM DUAL;TO_DATE('01-1月-2007')----------------------2007/1/1...
-
编辑 删除
functions
round trunc initcap
-
编辑 删除
null与index
今天在测试过程中遇到一问题, SQL该走Index的,没走. 加index hint也不行. 描述如下:1. 建立测试表create table t1asselect object_id, object_name from dba_objects;2. 在object_name列上建立b-tree indexcreate index idx_t1_name on t1(object_name);3. 如果我是select object_name from t1, 按理说CBO...
-
编辑 删除
关于INTERVAL DAY TO SECOND数据类型
INTERVAL DAY TO SECOND类型
-
编辑 删除
Cache buffer的状态
Buffer StatesThe database uses internal algorithms to manage buffers in the cache. A buffer can be in any of the following mutually exclusive states:■UnusedThe buffer is available for use because it has never been used or is currently unused. This type of buffer is the easiest for the database t...
-
编辑 删除
alter database create datafile
alter database create datafilerecover database using backup controlfile
