Oracle

Oracle gets the current date and date formatGet system Date: Sysdate ()Formatted Date: To_char (Sysdate (), ' Yy/mm/dd HH24:MI:SS)or To_date (Sysdate (), ' Yy/mm/dd HH24:MI:SS)Formatted number: To_number                Note:      to_char  Convert a

View definition:-- view is a virtual table. -- The view is based on existing tables, and the tables on which the views are built are called base tables.-- The statement that provides the data content to the view is a SELECT statement that can be

Or the use of silent installation, manually built the library after completion. This error has been reported at the time of installation of the OEM. Here is a slightly documented solution:Database connection through listener failed. Fix the error

Oracle Note One, Oracle installation, sqlplus useOracle Note II, Common DBA command lineOracle notes three, function, selectOracle notes Iv. Deletions, transactionsOracle Notes v. Create tables, constraints, views, indexes, sequences, synonyms,

I. OverviewIn the company, we often face a situation. After we have worked out the operation of the database, we can not execute it on the real database, we need to test it in the standby database, the data on the backup data and the real database

# su-oracleOracle> sqlplus "/as sysdba"sql> exec dbms_scheduler.disable (' Monday_window ');sql> exec dbms_scheduler.disable (' Tuesday_window ');sql> exec dbms_scheduler.disable (' Wednesday_window ');sql> exec dbms_scheduler.disable ('

"Odp.net Managed" has been released for some time, recently there is a new project, want to try to use, refer to the Garden article: ". NET Oracle Developer Gospel--odp.net Managed officially launched" to the Oracle website download ODP.NET_Managed12

Tomcat 5.5.23Oracle 10gGlobal configurationA. Tomcat directory \common\lib add package Ojdbc14.jar.Two. The Tomcat directory \conf\server.xml tags are insertedConnection parameters for Oracle:Type= "Javax.sql.DataSource"Driverclassname=

Simple Introduction to ConstraintsConstraints are used to ensure that database data meets specific business logic or enterprise rules, assumptions define constraints, and data does not match, the DML operation (INSERT, UPDATE, DELETE) will not run

When we process the results of the query, (for example: Sal*13+comm expression), because some employees may not have a bonus, only 1 March salary, so that we investigate the results will be incorrect, the results only show that there are both

Oracle Cluster Ready Service (Oracle Cluster Readiness Services)Amnesia: Amnesia, configuration information in multiple nodes is not uniform, with the old configuration file, resulting in configuration loss.Use OCR to resolve in RAC.Split Brain:

1. Create packages (Package)Function:Create or replace package name as functionNote: Multiple functions can be added after asStored procedures:Create or replace package name as stored procedureNote: Multiple stored procedures can be added after as2,

--Create Session temp TableCreate global temporary table tmp_user_session (user_id int, user_name varchar2 (), User_email varchar2 (30))--This sentence indicates that the data is persisted when the transaction commitsOn commit Preserve

A tablespace is a logical division of a database, and a table space can belong to only one database. All database objects are stored in the specified table space. But the main storage is the table, so called table space. There is at least one

This paper collects common database queries and requires database administrator privileges:1. Query Temporary tablespace usageSELECT tablespace_name, tablespace_size/1024/1024 tablespace_size_mb, allocated_space/1024/1024 ALLOCATED _SPACE_MB,

1. Delete the primary key ALTER table TABLENAME drop primary_key Run the above SQL to remove the primary key; Assuming that the ALTER TABLE TABLENAME drop CONSTRAINTS COLUMN Cascad is not successful E --delete constraint alter TABLE TABLENAME

--------System Permissions--------Create userCreate user Zc Identifid by ZC; --Create UserGrant create session to zc;--creating user login PermissionsRevoke create session from zc;--Contact User Login permissionAlter user account unlock; --Modify

[Index] basic knowledge of joint index and joint index 0. Preparation Suppose we have the table user (id, name) Column 1. What is composite index? We know that you can index a single column (such as id) of a table,For multiple columns (combination

Oracle foreign key constraint child table and parent table Create table employees ( Employee_id NUMBER (6 ), Last_name VARCHAR2 (25) not null, Email VARCHAR2 (25 ), Salary NUMBER (8, 2 ), Commission_pct NUMBER (2, 2 ), Hire_date date not null,

Use of rownum in Oracle for sorting in result setsUse of rownum in Oracle for sorting in result setsFor the rownum problem in Oracle, many documents do not support>, >=, =, between... and. The preceding symbols can only be used (,> =, =, .. and will