Oracle

The sample code is as follows: --Create Public database link Test_link CONNECT to Scott identified by Tiger using ' (DESCRIPTION = (Address_list = (ADD RESS = (PROTOCOL = TCP) (HOST = 127.0.0.1) (PORT = 1521))) (Connect_data = (service_name = LEE)

C:/>sqlplus Sql*plus:release 9.2.0.1.0-production on Saturday September 29 15:08:34 2007 Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved. Please enter user name: SYS as SYSDBAPlease enter password: Connect to:Oracle9i Enterprise

Union/union All operation: Combines the query's return into one result, and union all does not filter the duplicates. Select product_id from Order_items UNION select product_id from inventories; Select location_id from locations UNION All

 --Query table space usageSelect UPPER (f.tablespace_name) "Table space name", D.TOT_GROOTTE_MB "Table space size (M)", D.tot_grootte_mb-f.total_bytes "used Space (M)", To_char (ROUND (d.tot_grootte_mb-f.total_bytes)/d.tot_grootte_mb * 100,2), ' 9

Approach One SELECT * FROM V$nls_parameters $conn = Oci_connect (' Scott ', ' Donkey ', ' demo ', ' ZHS16GBK '); while ($dat = Oci_fetch_row ($cur)) {Print_r (Iconv (' gb2312 ', ' utf-8 ', $dat [0])); $nickname = mb_convert_encoding ($dat [0], ' utf-

I. Introduction TO Cursors: A cursor is a control structure in a pl&sql. Can be divided into explicit and implicit cursors. Pl&sql creates an implicit cursor for each SELECT statement. But when we need to process more than one piece of data, we need

Binutils-2.20.51.0.2-5.11.el6 (x86_64) Compat-libcap1-1.10-1 (x86_64) Compat-libstdc++-33-3.2.3-69.el6 (x86_64) compat-libstdc++-33-3.2.3-69.el6.i686 Gcc-4.4.4-13.el6 (x86_64) Gcc-c++-4.4.4-13.el6 (x86_64) Glibc-2.12-1.7.el6 (

Determine if the table exists, if it does not exist, and then create: declare tableexist number;BeginSelect COUNT (1) into the tableexist from User_tables where Table_name=upper (' onecallprtcp ');If tableexist = 0 ThenExecute immediate' CREATE

Bitmap indexes apply to low cardinality (low-cardinality) columns, and the so-called low cardinality column means that the column has very few desirable values. Problem with bitmap indexing:With a bitmap index, one key points to multiple rows,

ALTER TABLE UserInfo Add (msn varchar2 (20)); 1, build the table CREATE TABLE UserInfo ( ID Number (6), Name VARCHAR2 (20), Sex number (1), Age Number (3), Birthday date, Address VARCHAR2 (50),

It is particularly important for Oracle-behind developers to understand Oracle multiple versioning and consistent reading, because it greatly improves the parallel operation of the database. If you are not aware of concurrency, you typically

With Oracle for several years, we've all heard about some of the day-to-day development and optimization techniques, and simply list 1: Query performance for Tanku To see the amount of data, query conditions, whether hit the primary key, index, if

Topic: Known Company Employees table EMP (EID, ename, Bdate, SEX, city), Department Table Dept (DID, Dname, dcity), Worksheet work (Eid,did,startdate,salary). Each field is described as follows: eid--employee number, up to 6 characters. For example

T_medflow table has 10 million data flowid is primary key has primary key index Total number of statistics Select COUNT (flowid) from T_medflow t Spents: 1.5 seconds Select COUNT (*) from T_medflow t Spents: 1.46 seconds Multiple test efficiency is

Logminer provides a process for processing a redo log file and translating its contents into an SQL statement that represents a logical operation on the database . Logminer is running in Oracle version 8.1 or later. one, how to use Logminer:

Bulk INSERT Data mode: One, MyBatis global set batch processing; Second, MyBatis local set batch processing; Three, MyBatis foreach BULK Insert: ①select UNION All; ②begin INSERT into ...; insert INTO ...; ...; End; Four, Java with the batch

Users have a requirement to access the Oracle database using C + +, and then open the C + + database programming book. C + + (VC) database access technology has Odbc,dao, ADO (OLE DB) and other technologies, these are common C + + database access

Pk: Primary key, cannot repeat, non-empty Fk: Foreign key, reference to another table PK, you can repeat. Union PRIMARY key: a 2-table PK is referenced as the primary key for this table. Application Example: Build three tables, increase the

1. Basic grammar This is a must, what select,insert,update,where and so on. Mastering this knowledge can basically do some work with validation and testing. Target positioning Yu YUNWI or testing. 2. Preparation of stored procedures To know how

  CREATE OR REPLACE FUNCTION f_pinyin (p_name in VARCHAR2) return VARCHAR2 as V_compare VARCHAR2 (100); V_return VARCHAR2 (4000); FUNCTION F_nlssort (P_word in VARCHAR2) return VARCHAR2 as BEGIN return Nlssort (P_word, '