Oracle

How is duplicate data removed from the Oracle database? When working with data tables, there are often duplicate data, so how do you delete them? Let's talk about removing data duplication from Oracle databases. There are two ways we are going to

1.DML TriggerAs the name implies, DML triggers are triggered by DML statements. For example, a database's insert/update/delete operation can trigger a trigger of that type. They can be triggered either before or after these statements, or at the row

Generate a time in Java with a date and a month, and save the Hibernate object to the Date field in Oracle.The first method:The CreateDate property of the Java entity class, type Java.util.DateHibernate mapping file Command.setcreatedate (New

It is said that Oracle has implicit conversions of number and VARCHAR2 types, which need to be avoided in strict sense, but why it needs to be avoided and validated from the following experiments.1. Creating test tables and IndexesCREATE TABLE tn

Requirement: Automatically backs up the Doiido user's database at 23 50 per day, and keeps backup information for 30 days.1: Writing Oracle Environment scripts$ VI oracle_hj.shOracle_base=/doiido/oracle; Export Oracle_baseoracle_home= $ORACLE _base/1

After the first chapter of the basic data operation instructions are practiced, some operations of the database are performed. Create a table class has two columns: numbers and names: CREATE table Class (numbers number, names char (20));This

CREATE TABLE Products (ProductID Number (TEN) is not NULL,Name VARCHAR2 (255),Description CLOB);Query statement:Select T.productid, t.name from Products twhere Dbms_lob.instr (t.description, ' AAA ', 1, 1) > 0;In Oracle, you can use the InStr

export exported data, DMP file, is actually a select.Import imports data, is actually insertDefect: Export requires full table export, slow, not real-time, and logical backup1:expExp Export is divided into several modesTable mode: Export the table

The Oracle Intercept character (SUBSTR), which retrieves the character position (instr), when the then else End statement uses the favoriteCommon functions: Substr and InStr1.SUBSTR (String,start_position,[length]) to substring, return

Oracle implements database as a cloud service Wu Chengyang, vice president of Oracle and General Manager of the Greater China technology product department, supported the basic concept of database as a service to realize the cloud environment.

Powerful booster for Oracle database selection to optimize data centers In the era of cloud computing and big data, the ever-changing business environment puts more stringent requirements on enterprise IT infrastructure. In order to provide strong

OracleSPM Execution Plan Management **************************************** * ******************** Part 1: concept *************************************** * ******************* SQL scheduler management is a new function introduced with Oracle

Oracle flash back flashbackFlash back: fixed a logic error and returned from the current point.1. There are dedicated flashback logs stored in the FIA, but they are only used in the database. 2. If a full database flash is performed, it is

Oracle users unlock lockd The following error is reported when the user doiido connects to oracle: ORA-28000: the account is locked View user statusSQL> conn/as sysdba SQL> SELECT username, account_status FROM dba_users; USERNAME

Import/Export exp/imp from OracleExport: The dmp file is actually select.Import data is actually insert Defect: full table export is required during export, which is slow, not real-time, and logical backup 1: EXP Exp export is divided into several

Archivelog related to Oracle archive ModeEnable archive Mode> Archive log list;> Shutdown immediate;> Startup mount> Alter database archivelog> Alter database open;> Archive log list;View the archive mode and the archive storage path> Show parameter

Oracle automatic backup script Requirement: the user's database is automatically backed up at every day, and the backup information is retained for 30 days. 1: Write an oracle environment script $ Vi oracle_hj.sh ORACLE_BASE =/doiido/oracle;

Oracleasmalias file alias Today, I saw a friend on the Internet asking: Why did I set log_archive_dest_1 In the ASM storage management mode to specify the archiving path, but I found two archived log files in ASM? (Not flashing back) I checked

Oracle compares two table structure differences and data differences. oracle differences In the work, we need to fulfill the following requirement: compare the two tables with the same structure and find the difference. Compare the two tables with

Oracle Database Import When the system was deployed at the electronic Institute in March October, the export and import of the Oracle database were successful using the exp and imp export database commands, I also published an article on Oracle