Oracle

One, the string functionLower (string) lowercaseUpper (String) uppercaseInitcap (String) Capitalize first letterConcat (column 1, column 2) two-column mergeLength (string) by wordLENGTHB (String) in bytesLENGTHC (string) length of Unicodesubstr

The use of the--oracle trunc () function/************** Date ********************/1.select trunc (sysdate) from dual--2011-3-18 today's date is 2011-3-182.select trunc (sysdate, ' mm ') from dual--2011-3-1 returns the first day of the month.3.select

Prelude: The necessary concept: ORACLE provides the ability to store PL/SQL programs in a database. And be able to run it everywhere. This is called a stored procedure or function. Procedures and functions are collectively referred to as PL/SQL

Ratio_to_report--List Sales totals per month of the previous year, year-end sales, and monthly sales as a percentage of total annual sales--method ①:SelectAll_sales.*, - * round(Cust_sales/Region_sales,2)|| '%' Percent from (SelectO.CUST_NBR

I. Statistical aspects:Sum() Over([Partition by] [Order by])Sum() Over([Partition by] [Order by]RowsbetweenPreceding andfollowing)Sum() Over([Partition by] [Order by]RowsbetweenPreceding and CurrentRow)Sum() Over([Partition by] [Order

1) The simplest formSQL Code-- confirmed that all customer_id less than 1000 in the Customers table are ' Beijing ' --within 1000 of the company to the country before the old customers of the city:)update customersset city_name=' Beijing 'where

Tag: T-SQL statement cannot execute under stored procedure call instead of Div Note command executionWhat is a stored procedure? A stored procedure is a named PL/SQL program block, which is a block of code that consists of some T-SQL statements that

1 --Oracle Data Backup (three methods)2 --1. Logical backup and Recovery: Using Oracle-provided tools, import/Export (EXP,IMP), Data3 --Pump Import/Export (IMPDP,EXPDP), loader (Sql*loader)4 --2. Offline backup and Recovery: refers to the physical

Read consistency: Oracle guarantees read consistency through multiple versions and flashback mechanisms. Ensure that queries are consistent from one point in time. In Oracle, the version of the system modification is controlled primarily by the SCN

AuditTurn on switch parameters:Sql> Show Parameter Audit_trailSet audit options:Each time a new audit option is set, the test user needs to reconnectSYS preparation:sql> drop user User01 cascade;Sql> create user User01 identified by password;Sql>

Database managementThere are 4 ways to close the database:1.shutdown Modes shutdown mode2.shutdown Normal shutdown3.shutdown immediate immediately close ★ Common commands4.shutdown abort directly shuts down the databaseStartup: RestartDbstart:

Oracle The version is very many, first look at a version of the 11g description:Attention: after the Oracle 9.2 version number, Oracle's maintenance release numbers are changed at the second digit bit. And before that is in the third digit digit.1.

Introduction to Oracle DatabaseMaybe a lot of people are familiar with SQL Server, not much about Oracle database, here is a brief introductionThe founder of Oracle database is Lawrence Ellis.Oracle database can be used by multiple operating

1. Access to Computer Management >> services, stop all Oracle Services2. Start Menu >> program >>oracle>>oracle Install product >>universal Installer, run the programSelect "Uninstall Product";Select "Expand All" and then select "Delete" after all

Self-connect:Empid ename Mgridabc101 def 100102 XYZ 100Emp:mgr:Empid ename Mgrid Empid mgrnameABC (ABC)101 def 100102 XYZ 100101 DEF-ABC102 XYZ (ABC)Select Emp.ename, Mgr.mgrnameFrom EMP, Mgrwhere Emp.mgrid=mgr.empidEmp:mgr:Empid ename mgrid empid

An Oracle database object, also known as a schema object, is a collection of logical structures in which the most basic database object is a table. Common database objects include synonyms, sequences, views, and so on.1. ViewViews can restrict a set

Oracle Paging: Keyword rownumSELECTEMPNO,ENAME,JOB,MGR,HireDate,SAL,COMM,DEPTNOFrom(SELECT a.*, ROWNUM RNFrom (SELECT EMPNO,ENAME,JOB,MGR,To_char (hiredate, ' yyyy-mm-dd ') hiredate,SAL,COMM,DEPTNOFromEmpORDER by EMPNO) AWHERE ROWNUM

Silent Installation Reference: http://www.cnblogs.com/colmeluna/p/5686142.htmlIn the actual installation:1. Skip the second step to set the swap area space2. No prompt to execute orainstroot.sh after installation is complete, only root.shBuild

Error occurredORA-01034 ORACLE Not availableORA-27101 Shared Memory Realm does not exist　　　　WorkaroundStart monitoring:#lsnrctl startStart Oracle Services$sqlplus/nologSql> Conn/as SYSDBASql> StartupStart Oracle ServicesError

1. You can use the VI command to view files under Linux in a similar notepad.2.Redhat shut down the firewall, command systemctl Stop FIREWALLD view the Firewall status command systemctl status FIREWALLD3. Log in to the database Sqlplus/nolog