Oracle

next_day (date, char): returns the date of the first day of the week (specified by char) after the specified date (specified by date). Char can also be 1 ~ Replace 7. 1 indicates Sunday. Duzz $ Scott @ orcl> select sysdate, to_char (sysdate, 'day')

  When creating an instance, you can save it as a template. In fact, you can also use the dbca command to create an instance template and use this function to copy the instance. This feature is rarely noticed.     Here we choose

Having is mainly used to filter grouped data, Generally, we connect the aggregate function (sum, Count, etc.) after it ), In addition, we can use the fields following group by to form the having filter conditions.   SQL> select * from Dept; deptno

Why use? 1. If you need to apply the same query multiple times in a complex query, use with to implement code reuse; 2. With query is similar to retaining the query results to the user's temporary table. Io can be reduced in large and complex

Reprinted: http://www.hellodb.net/2011/09/oracle-database-appliance.html Since Oracle acquired sun, it not only obtained MySQL, Java, Solaris, but also Sun's hardware products. It has truly become a service provider of hardware and software kill.

Put the Escape Character (^) out of square brackets ([]) to match strings starting with any character in square brackets; Put the Escape Character (^) in square brackets ([]) to match strings containing any characters not in square brackets. SQL>

  The Oracle version in this document is 11.2.0.1. No OEM was installed before. An error is reported when dbca is used for installation today. The error page is as follows:     I have previously reviewed an OEM reconstruction method: Oracle OEM

  In Oracle10g, if the installation example is not selected during instance creation, you can create an instance using the script under $ ORACLE_HOME/demo/Schema after the instance is created. For details about the creation method, the official

 1. Oracle 11G default audit description An article on auditing is as follows: Oracle Audit audit description Http://blog.csdn.net/tianlesoftware/article/details/4712932 On Maclean's blog, I saw two articles about Oracle 11G default audit. The

You can view an all_parameters table in dbsnake's blog. You can use this table to view hidden parameters. But I confirmed later that this table is not available. Therefore, this is a view created by dbsnake.   How to view Oracle parameter categories

Suppose a subprogram declaresINParameter,OUTParameter, andIN OUTParameter. When you call the subprogram,INParameter is passed by reference. That is, a pointer toINActual parameter is passed to the corresponding formal parameter. So, both parameters

  Toad 10.6 queries the Oracle 10g tablespace. The following message is displayed on the toad return page: Selectprivileges on following are required: dba_data_files, dba_free_space, V $ temp_space_header, V $ temp_extent_pool,

 I. RBA description I have prepared a description document for rdba and DBA. For details, refer: Oracle rdba and DBA description Http://blog.csdn.net/tianlesoftware/article/details/6529346   In the mos documentation, question about RBA (redo block

Duzz $ Scott @ orcl> select employee_id, last_name, job_id, manager_id 2 from employees 3 Start With employee_id = 101 4 connect by prior employee_id = manager_id; (Prior: Previous, first, perform recursive queries based on the previous employee_

SET transaction read only is actually a means of implementing isolation (isolation) in four major acid databases, which is used to set the read consistency of data at a certain time point, that is, no matter how the data of other transactions is

One mistake can lead to a lot of work. when you 've installed Oracle Database 11g, you can't change the Windows hostname without reinstalling Oracle Enterprise Manager. these are the steps: 1. change the % ORACLE_HOME % \ Network \ admin \

Test code: Declare type list_of_names_t is table of varchar2 (100) index by pls_integer; happyfamily list_of_names_t; l_row pls_integer; begin -- Build table data which index is not consecutive. happyfamily (2020202020): = 'lil'; happyfamily (

Rollup literally means to roll to, used in group by can play a cumulative sum role:   If no rollup exists, the following query sums the groups by department_id and job_id: Select department_id, job_id, sum (salary) from employees where

The use of group by grouping sets is equivalent to Union all for the set requiring group. When there are more grouping elements in grouping sets, the performance of using grouping sets is better than using Union all, which may be related to using

NullNoGreater than/less than/equal to/not equal to any value (including null itself), and only:Null is null SQL> set serveroutput on SQL> begin 2 if (2> null) 3 then 4 dbms_output.put_line ('>'); 5 elsif (2 6 then 7 dbms_output.put_line (' 8