Oracle

This article transferred from: http://blog.csdn.net/ludongshun2016/article/details/71453125The fields in the database are number types, and the corresponding integers and bigdecimal in the Java type will appear;The test found that when the database

Case: Open card information in the bank Field Field type Id Number Name VARCHAR2 (64) Sex CHAR2 () Birth Date Money Number (10,2)

1. After extracting the Oracle compressed files, open the directory and double click "Setup.exe" to start the installation.2. "Oracle Universal Installer" window pops up3, e-mail prompts, follow the default next action4, the second step directly

　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　Cursor Properties and Restrictions/*1. Cursor Properties%found%notfound%isopen to determine if the cursor is open%rowcount the number of rows affected2, the cursor limitBy default, the Oracle database allows only 300

Many times, we do a small batch of data migration will use the data pump, but 12C we want to configure TNS to specify the PDB import, but the public service we are through the cluster using SRVCTL to create. At this time preferred instances may have

Recently, because the table space of the customer data in the business is occupied too large, and want to reduce the size of the tablespace file by deleting some data, it is possible to use partition table to implementPartitioned tables are divided

Transfer from http://www.cnblogs.com/advocate/archive/2010/08/20/1804066.htmlDeepen your understandingThe database is a photographic film.Example is photo paperA film can be used to punch multiple photographic papers, but a photo paper is a maximum

1. Stitching strings1) You can use the "| |" To stitch a string2) through the concat () functionNote: Oracle's CONCAT function only supports two parameter methods, that is, only two parameters can be stitched together, if you want to stitch multiple

Delete statementBasic syntax:Delete from table name where conditionPrecautions:1, if you do not use the WHERE clause, all data in the table is deletedDelete from test;2, if you want to delete the value of a column, delete is not possible3, delete

CREATE TABLE Space--View all users, and the corresponding permanent table space, temporary tablespaceSelect Username,default_tablespace,temporary_tablespace from Dba_userswhere username= ' SYSTEM ';1.1 Creating a temporary table spaceCREATE

1.oracle View OperationsCreating view: Create view name as query data;Delete view: Drop view name;Cases:CREATE VIEW MyView as SELECT * fromTest_person;(You can modify the view, the modified data will affect the base table)CREATE VIEW MyView as

Is archiving mode really that important?For Oracle database, must be set to the archive mode, especially the production library, only in order to achieve a valid database full recovery, for security, remember.It is dangerous for some databases to be

Attempt to load Oracle client libraries threw badimageformatexception. This problem would occur when running in a bit mode with the-the-bit Oracle client components installed. ---> system.badimageformatexception: An attempt was made to load an

--Execution in---sqlplus (awr time period)@?/Rdbms/Admin/Awrrpt.sql-----Generate snapshots manuallyexecDbms_workload_repository.create_snapshot ();--statement Three executions, grouped into snapshots--Querying SnapshotsSelect *

1. First we can log in to Oracle as SYSDBA as a Scott user.Conn Scott/ as Sysdba 2. Then I'll be able to create the user.Create User by 123; 3. Create a good user we can then modify the user's password.Alter User by Chen; 4. By default, the

Recently contacted Oracle again for work reasons, so re-acquainted with Oracle's basic commands.--Change Password1. Run-type "cmd" carriage return2. Type "Sqlplus/nolog" carriage return3. Type "Conn/as sysdba" carriage return4. Type "ALTER user

/*oracle user Lock, database lock sometimes compared to eat resources, if a large number of resources consumed, then other applications will not have the resources to use, it will be abnormally closed or unable to open. When Oracle has a lock

Enter the machine and set the environment variables, such as:Export oracle_home=/main/app/oracle/product/11.2. 0/db_1export oracle_sid=devdbThen switch Oracle user, admin mode login Sqlplussu - oracle[[email protected]~]$ sqlplus/nologsql>

When Oracle performs some DML operations, it has the flag of the active transaction on the Oracle block, if a transaction commits, because some blocks have been written back to DataFile before commit, or if the transaction affects too many blocks,

1. Login: sqlplus/@orcl as Sysdba2. Snapshot: Exec dbms_workload_repository.create_snapshot3.AWR report: @ $ORACLE _home/rdbms/admin/awrrpt.sqlIf you don't set Oracle_home, you'll find the exact