Oracle

--View the single table structure of an Oracle databaseSelect Dbms_metadata.get_ddl (' TABLE ', ' table_name ') from dual;There are two parameters in parentheses, the first parameter is the object we want to query, here is the table structure, so it

Oracle Import failed, the length of the ORA-12899, is the character set caused by the Chinese in the UTF-8 accounted for 3 bytes, zhs16gbk accounted for 2 bytes, and the source DMP file character set is ZHS16GBK the data poured out of the

Primary users and their roles in Oracle databases No. User name Default password Describe 1 Sys Change_on_install Super Administrator of the database 2 System Manager

Common versions of Oracle databases In the development of Oracle database, the database has been in a state of continuous upgrade, with the following versions: Oracle 8,oracle 8i:oracle 8i means Oracle is formally evolving to the

1--1. Creating a Test Table 2 CREATE TABLE job_test (ID integer,add_time date); 3 4--2. Creating a Stored procedure5 Create or Replace procedurePrc_job_test is 6 begin 7 Insert intoJob_testValues(Seq_tm_id.nextval, sysdate); 8 Commit; 9

Installing Oracle-database-server-12cr2-preinstallwget http://public-yum.oracle.com/public-yum-ol7.repo -O /etc/yum.repos.d/public-yum-ol7.repowget http://public-yum.oracle.com/RPM-GPG-KEY-oracle-ol7 -O /etc/pki/rpm-gpg/RPM-GPG-KEY-oracleyum clean

--To view the maximum number of connections to a databaseSelectValue fromV$parameterwhereName ='Processes';--change the number of database connectionsAlter systemSetprocesses = theScope =SPFile;--to view locked

1 Install Oracle Client on Windows.2 Ensure that the 1521 ports on the Linux server are open.3 See your window machine is enough to ping the IP address of the Linux server 4 in the Oracle client's Tnsnames.ora in Windows add the Oracle (that is,

View database Character Set encodingSelect USEREVN (' language ') from dual;Oracle Common functions:LOWER (' AAAAA '), convert all characters to lowercaseUPPER (' aaaaasss ') to convert all characters to uppercaseInitcap (' Atsichuan Chengdu '),

--Each month in the time period, {0}: Start date, {1}: End Date Select To_char (Add_months (To_date ('{0}','yyyy-mm'), ROWNUM-1), 'yyyymm'As monthlist from DUAL CONNECT by ROWNUMMonths_between (To_date ('{1}','yyyy-mm'), To_

prompt Create a function F_getprocnameCREATE ORREPLACEFUNCTION f_getprocname RETURN VARCHAR2-- gets the name and caller of the function or stored procedure itself isL_ownerVARCHAR2( 30);L_nameVARCHAR2( 30);L_linenonumber; L_typeVARCHAR2( 30);

table spaces and data files1. Tablespace is a disk logical space for a database.2. Each table space consists of one or more data files.3. A data file can only belong to one table space.After completing the Oracle system installation and creating an

StaticOracleConnection mqracleconnecting =NULL; Public Staticoracleconnection qracleconnecting {Get { Try { if(Mqracleconnecting = =NULL) mqracleconnecting=NewOracleConnection (JKSG);

The dump function is used to determine whether a character type in a string belongs to number or stringStored ProceduresCreate or Replace procedurePro_isnum (i_stringinch varchar2, O_note outvarchar2) asstring1varchar2( +);--after the field is

1. Basic dataSELECT * from Table_muen TID CODE NAME Parentcode0 first-sbzhyw Social Security integrated ROOT1 Second-sbzhyw-zzyw self-service first-sbzhyw2 Third-sbzhyw-ywcxydy business Query and print Second-sbzhyw-zzyw3 Four-sbzhyw-grcbzmdy

Numeric functions:1.round: Returns the value after roundingRound (number, parameter) parameter does not write default to 0The following parameter specifies the precision of the return value, or the start of rounding from the beginning of the decimal

One, sys users and system usersThe Oracle installation automatically generates SYS users and system users(1), sys user is superuser, has the highest privileges, has the SYSDBA role, has the rights to create database, the user's default password is

How to modify the field order in an Oracle database table Preface Some time ago, someone asked me a question about the order adjustment of table fields in Oracle. The problem is that after the table structure is designed, if you need to add a field

Oracle where condition execution sequence analysis 1, oraclewhere (1) execution sequence of statement ParsingCreate a function for testingCreate or replace function F1 (v_in in varchar2)Return varchar2 ISV_out varchar2 (20 );BeginV_out: =

Solve the Oracle string Sorting Problem that contains numbers and special symbols. Problem description: A residential area needs to be sorted by the residential area, building, unit number, and room number. However, when sorted by the address