Oracle

Query, disable, enable, and delete Foreign keys in Oracle 1. query the Foreign keys of all tables: Select table_name, constraint_name from user_constraints where constraint_type = 'R ';   2. Disable all foreign key constraints and use the

-- Enter the following commands on the terminal in sequence: Sqlplus -- Enter the username to be deleted -- Enter the password Set head off; Set feedback off; Spool c: \ drop_tables. SQL; -- CHR (13) ASCII = newline CHR (10) ASCII = carriage

Assume that the database network connection string is db_wending, the password is DBA/123, @ lk.comSqlplus (the password is enclosed in a pair of double quotation marks ):SQL> alter user u_test identified by "DBAs/123, @ lk.com ";SQL> conn

Connect role: -- is the most basic and typical right granted to end users.Alter session -- modify a sessionCreate Cluster -- create a clusterCreate database link -- create a database linkCreate sequence -- create a sequenceCreate session -- create a

I heard that SQL Server and MySQL have top keywords and can return the first N records of sorting records. For example, select top 10 * From table_name order by col_name. I think Oracle must have similar functions, oracle uses the rownum keyword

Create or replace type mytable as table of varchar2 (100) Create or replace function split (SRC varchar2, delimiter varchar2)Return mytable isPsrc varchar2 (500 );A mytable: = mytable ();I number: = 1 ;--J number: = 1;BeginPsrc: = rtrim (ltrim (SRC,

The start with... connect by clause recursive query is generally used for a table to maintain a tree structure. Create example Table: Create Table tbl_test ( ID number, Name varchar2 (100 byte ), PID Number default 0 ); Insert test data: insert

A sequence is a database object that can be used to generate a unique integer. Generally, the sequence is used to automatically generate the primary code value. The value of a sequence is composed of special Oracle Program Automatic Generation, so

Create Table Areas ( Radius number (5 ), Area Number (14,2) ); Method 1: Use GOTO DeclarePi constant number (9, seven): = 3.1415927;Radius INTEGER (5 );Area Number (14, 2 );BeginRADIUS: = 0;LoopRADIUS: = radius + 1;If radius = 4ThenGoto

-- Create TableCreate Table hkb_test3(User_id number (4 ),Age number (4 ),User_number number (4)) SQL> select * From hkb_test3; User_id age user_number-----------------------1 122 143 164 11Example: Update hkb_test3Set user_number = (select B.

Oracle segment:First, create a package and package body in Oracle, and define the function and the returned result set of the stored procedure.1: Create a package:Create or replace package Scott. pk_wtIsType mytype is ref cursor;Procedure p_wt (MYCS

My colleague encountered a strange problem. A join query of three tables took about several seconds, and a restriction condition should be added to the query faster, but the results would not end up being executed. Then I looked at the execution

In the past few days, a project using nhib.pdf has been transplanted from SQL Server to Oracle (using odp.net). After transplantation, it is found that the unit test is much slower, determine whether it is related to nhib.pdf and odp.net. In the

Copyright (c) 2007 Dorian Deng. Signature Sharing is not commercially available.Reprinted please indicate the source: http://www.cnblogs.com/doriandeng/archive/2007/10/05/914834.html Preface: During project development using databases, query

When I am working on a project today, I need to insert multiple data records to the database (the database is Oracle 8.0.5) at a time,ProgramAn error occurred while running: ORA-00911: invalid characters. The SQL statement is as follows: Delete

With the query syntax unique to Oracle, you can get twice the result with half the effort. 1. Tree Query Create   Table Tree (ID Number ( 10 ) Not   Null   Primary   Key ,Name Varchar2 ( 100 ) Not  

During SQL Execution, sometimes the automatic optimization method is not optimal. We need to manually add hint to improve query efficiency.1./* + all_rows */It indicates that the overhead-based optimization method is selected for the statement block,

1. Usage Overview Why access WebService in Oracle? In system implementation, sometimes data transmission and distribution services are directly performed on the database using triggers, stored procedures, and other methods, which may involve some

This blog is a summary of the previous Linux Shell common skills and advanced skills series blogs. It will explain and explain the script of Oracle database server startup line by line, to help us better learn and understand the common skills and

Symptom:SQL> select rownum, emp. * from emp; ROWNUM--------------------1 12 23 14 1 SQL> select rownum, emp. * from emp where rownum ROWNUM--------------------1 12 2 SQL> select rownum, emp. * from emp where rownum = 2; Unselected row Explanation (