Oracle

As follows: BEGIN SELECT name into v_name from t_student WHERE id = ' 101 ' EXCEPTION when no_data_found Then v_name: = "; END;In this way, you do not have to select COUNT (1) from t_student where id = ' 101 ' in advance

Object Types for Oracle Object TypeIn PL/SQL, object-oriented programmers are based on object types. The object type is a user-defined composite data type that encapsulates the data structure and the procedures and functions used to manipulate those

Here's an example:Select substr (' ll$ $BOAT $ $he very handsome ', 1, InStr (' ll$ $BOAT $ $he very handsome ', ' $$ ', 1, 1)-1), substr (' ll$ $BOAT $ $he very handsome ', InStr (' ll$ $BOAT $ $he very

Create directory gives us the flexibility to read and write files in an Oracle database, greatly improving the ease of use and scalability of Oracle.Its syntax is:CREATE [OR REPLACE] Directory directory as 'pathname';This case is specifically

After restoring a database on the Oracle test server, a TNS-12541, tns-12560,tns-00511 error occurred when starting the listening service, as shown in the following scenario:[Email protected] admin]$ lsnrctl statusLsnrctl for linux:version 10.2.0.4.0

Oracle TIP error message ora-28001:the password has expiredLog in with Sqlplus/as SYSDBA on the Oracle server to view the account status using the following SQL statement:Select from Dba_users;Find the corresponding user name, if the status is

1. Client-side encodingView method: Open the registry of the server where the database resides (enter regedit in the Run window) Hkey_local_machine->software->oracle->home0->nls_lang, Check out what the database client code is.2. Server-side

Once encountered such a requirement: Request for method passed in string, content such as "user ID0, user ID1, user ID2 ...", and then according to these IDs return a result set as a data table for others to query.SELECT * FROM TBL WHERE ID IN

The Oracle 11g is usedIn fact, it has been a few, but not much study, now began to re-learn, including SQL statements and so on.Start after installation,I installed the client sqldeveloper, but I need to connect after entering, I forgot how to do it,

Oracle ora-01033:oracle initialization or shutdown in progress error resolution"ORA-01033" error when logging into databaseIn the command window, log in as sqlplus as sysdba--note that the value after the sqlnet.authentication_services parameter in

a) Date function [focus on the first four date functions]1.add_months[return date plus (minus) The date after the specified month (before)Add_months (D1,N1)"Function": Returns the new date after the date D1, plus N1 months."Parameters": D1, Date

Ii. Oracle's parameter file management1. Introduction of parameter FilesTwo types of parameter files:(1) spfile parameter file (binary file)(2) pfile parameter file (text file)Path to the parameter file store: $ORACLE _home/dbs[email protected] dbs]$

First, the principle of startup and shutdown of Oracle1. Oracle Boot Step AnalysisSql> Startup-This is the command to start the databaseORACLE instance started. --first stage, launch instance, Nomount stateTotal System Global area 608174080

Indexes in OracleIn a relational database, an index is a database structure that is related to a table and is another important schema object other than a table. An index is a helper object that is built on one or more columns of a table to increase

The structure of the Oracle IF statement is similar to most languagesIF condition then expr; elsif condition then expr; ELSE expr; END IF;As an example:Select count (Distinct index_name)  INTO CNT FROM USER_INDEXES WHERE  Table_name=c1. table_name;  

Decode function usage in OracleMeaning explanation:Decode (condition, value 1, return value 1, value 2, return value 2,... Value N, return value N, default value)The function has the following meanings:IF condition = value 1 ThenRETURN (translation

Oracle statistics collectionCollect statistics 1: Create an analysis table $ Cd $ ORACLE_HOME/rdbms/admin $ sqlplus/as sysdba> @ utlxplan. SQL 2: For convenience, you can create a synonymous table (by default, only sys users can use it) SQL>

Oracle inversion Function Oracle provides a reverse inversion function, reverse, but this function cannot be used for grouping inversion. This article provides a function that can be used for grouping inversion, as shown below: Create or replace

Some advanced management case studies of ORACLE11GDataGuardAfter setting up ORACLE 11G dataguard, I also conducted a Role Switching experiment. switchover has failover, and I feel a lot of benefits. Then I continue to study some of the advanced

Auto increment of ID fields in the SQL _Oracle table Objective: To automatically increment the ID field when inserting data into a table. Start the experiment: (1) Create an experiment table Createtable test_ID_add ( Id number (10 ), USERNAME