create or replace view

This time, you must learn a new concept-VIEW ). As mentioned in previous notes, data objects include tables, views, sequences, indexes, and synonyms. The previous notes are all about table analysis, so this note will analyze the View world in depth.

Oracle study notes 9 database objects, oracle Study NotesOracle database objects are also called schema objects. database objects are a set of logical structures, and the most basic database objects are tables. Other database objects include:

First, Oracle's dictionary and Dynamic Data dictionary views can basically be divided into three levels. 1.x$ table This section of the table is the basis for the operation of the Oracle database, which is dynamically created by the Oracle

1. Why Use Views:To improve the reusability of complex SQL statements and the security of table operations (for example, the Payroll field does not want to be shown to anyone who can view the query's results), MySQL provides view features. A view,

The definition of a multiple-table view is a single table view when the data source for the view has only one datasheet, and the view is a multiple-table view when the data source of the view is multiple data tables.Updatable view definition: In the

Recurring problem A few days ago because someone deleted the records in the database, today shut down the remote access function of the database, received a development report today, said that the user specified as a definer (' air ' @ '% ') does

1.select statementsSELECT * FROM Dept D displays all fields in the dept (Alias D) TableSELECT deptno, loc from dept display deptno and LOC field contents in Dept tableYou can also use arithmetic operations with functions such as SAL+30,SAL+NVL (comm,

Multi-line Turn stringThis is relatively simple, with | | Or the CONCAT function can be implementedSQL CodeSelect Concat (id,username) str from App_userSelect Id| | Username Str from App_userString to multiple columnsis actually the problem of

Database--The basic concept and function of viewNovember 09, 2016 20:24:04Hits: 16506View (subquery): a virtual table that is exported from one or more tables whose contents are defined by the query. Has a structure of ordinary tables, but does not

Original: http://www.oracle.com/technetwork/issue-archive/2009/09-may/o39asktom-096149.htmlhow a constraint (constraints) in Oracle affects the query planOften people think that constraints are just about data integrity, no problem. But constraints

Reference article: http://blog.csdn.net/tianlesoftware/article/details/4704858Multi-line turn string This is relatively simple, with | | Or the CONCAT function can be implementedSelect Concat (id,username) str from App_userselect id| | Username Str

What are view "views"(1) A view is a virtual table(2) The view is based on existing tables, and the tables on which they are built are called base tables.(3) The statement that provides the data content to the view is a SELECT statement that can be

First, prefaceThe database currently used for the project is Oracle 12c, and one of the main reasons for selecting that version is to support JSON. One day, a perverted customer said to move to the cloud platform, but the cloud platform does not

In the afternoon, a table structure was exported from the production library to test for some problems, because the production library is connected to a table under other users, so by simulating it locally through the view, the view is

In the development of data integration, it is often necessary to create views for each other so that they can view some of the necessary data. Create a user in the database and assign permissions to the user to query the viewFirst, SQL

A view is a table that is visualized.This chapter explains how to create, update, and delete views.SQL CREATE View Statement What is a view?In SQL, a view is a table of visualizations based on the result set of an SQL statement.The view contains

A view is a table that is visualized.SQL CREATE View Statement What is a view?In SQL, a view is a table of visualizations based on the result set of an SQL statement.The view contains rows and columns, just like a real table. A field in a view is a

What is a view? ）1. A view is a database object, a virtual table that is exported from one or more data tables or views, and the data corresponding to the view is not really stored in the view, but is stored in the referenced data table, and the

In SQL, a view is a table of visualizations based on the result set of an SQL statement.The view contains rows and columns, just like a real table. A field in a view is a field from a real table in one or more databases. We can add SQL functions,

MySQL view of the study notes, learned to Tarena gold medal lecturer Heshan, Golden Dawn technology company technical Director Chalimoux Course notes synthesis.View and graphical tools1. definition of viewsA view is a table that is exported from one