Oracle

Oracle in Start With...connect by prior clause usageconnect by is used in structured queries, and its basic syntax is:1 Select from TableName 2 start with condition 1 3 Connect by Condition 2 4 where condition 3;Example:1 Select from Table 2 start

--undo Table Space Summary--View all tablespace namesSELECT NAME from V$tablespace;--Create a new undo table space and set your own active extension parameters;CREATE UNDO tablespace UNDOTBS2 datafile ' D:\ORACLE\PRODUCT\10.1.0\ORADATA\ORCL\UNDOTBS02

rowID is the detailed address of the data, the location of the specific data of a row can be quickly located by Rowid,oracle.rowID can be divided into two kinds of physical rowid and logic rowID . The rowid in a normal heap table is a physical rowid,

Pick up an article3 Configuring Environment Variables for OracleOracle_base=/u01/app/oracletmp=/tmptmpdir=/tmporacle_home= $ORACLE _base/product/12.1.0/dbhome_1oracle_sid= Orclexport oracle_sid oracle_base oracle_home TMP tmpdirpath= $PATH:.:

Because you want to update the database to add a table, Remote Desktop can not connect ... Therefore, remote to another computer, and then use Navicat through the intranet to modify the target database.has been using the navicat operation of the

Typical bug Analysis of Oracle character garbled and data out-of-bounds accessPreface: As party B, we found two strange bugs in the acceptance stage of party A's customers. Here's a detailed description of the source of the problem, the root cause

Issue: WIN8 64 uses bit system PLSQL developer Local connection Oracle inexplicably problems occur in the database. The error message box may even be empty.Reason: It indicates that the Internet, for reasons, is expected to be installed on a 64-bit

1. SOURCE Library:Sql> Show PDBscon_id con_name OPEN MODE RESTRICTED---------- ------------------------------ ---------- ----------2 pdb$seed READ only NO3 PDB READ WRITE NO4 TEST READ WRITE NO2. Target Library:Sql> Show PDBscon_id con_name

Et define off override variable functionThe default "&" in Sql*plus represents an alternative variable, that is, Sql*plus will ask you to enter an alternate value whenever the symbol appears in the command. This means that you cannot enter a string

Get table field:SELECT *From User_tab_columnswhere table_name= ' user table 'ORDER BY column_nameGet Table Comments:SELECT *From User_tab_commentswhere table_name= ' user table 'ORDER BY table_nameGet field Comments:SELECT *From

Data grouping,grouping function max, min, avg, SUM, Count Find the name of the person with the highest pay Select ename from emp where sal = (select Max (SAL) from EMP); 10% increase in salary for all employees below average

First, download: http://www.oracle.com/technetwork/database/features/instant-client/index-097480.htmlThis is the homepage of the Oracle Instant client download, and there are many versions available for download.But pay attention to third-party

One, the use of sys login,Second, Chan session_idFind stored procedure operationdata_imp by which sessionLocked and unable to compileSELECT * from dba_ddl_locks where name =upper (' Operationdata_imp ');third, Sid serial# detectedThus getting

Oracle 数据库审计功能非常强大，通常包括标准审计(包括用户级审计和系统级审计)和细粒度审计。尽管如此，一不小心就容易造成性能问题。同时会把系统表空间给撑爆。下面的内容描述的是如何将审计从系统表空间剥离以及清理Oracle审计记录，供大家参考。I. Audit-related configuration--EnvironmentSql>Select* FROM V$version where rownum=1; BANNER----------------------------------

The Lpad function fills the string with the specified character from the leftbasic Syntax: Lpad (String, Padded_length, [pad_string])String : Preparing the filled stringsPadded_length: The length of the string after padding, that is, the length of

There are different types of CLOB and Clob in Oracle.(oracle.jdbc.internal.OracleCallableStatement) Oraclecallablestatement can receive the CLOB data type,(java.sql.CallableStatement) The CallableStatement can receive CLOB data types.code

--1. Random numberSelect Dbms_random.value from dual;Select mod (Dbms_random.random, ten) from dual;--0-9 Random NumberSelect ABS (mod (DBMS_RANDOM.RANDOM)) from dual;--40-49 Random NumberSelect + ABS (mod (DBMS_RANDOM.RANDOM)) from

When Oracle is not installed on the computer, C # Calls oracle database and Oracle customer tools, The installation packages of Oracle are usually relatively large and time-consuming. If errors occur during the installation process, the installation

Database SQL optimization Summary-millions of database optimization solutions, Database SQL (1) select the most efficient table name sequence (only valid in the rule-based seo/'target = '_ blank'> Optimizer ): the ORACLE parser processes the table

Oracle Study Notes eight tablespaces and oracle Study NotesA tablespace is a collection of one or more data files. All data objects are stored in a specified tablespace. However, they are mainly stored in tables, which are called