Query Oracle view creation statement and how to insert data into the view [easy to understand]

Hello everyone , I meet you again , I'm your friend, Quan Jun .

Today, I will test the interface , Need to be in data Insert some test data into the Library . But when I was inserting data into the database , It is found that the interface queries the view, not the table , So the problems encountered are recorded here .

1. There are two situations when inserting data into the view

1.1 For simple views （ The view is built on a table ）, Just insert data directly like a table ;

1.2 For complex views （ View creation includes multiple table associations 、 grouping 、 Aggregate functions ）, You cannot insert data directly at this time , We should create a INSTEAD Type trigger to operate , Insert the data to be inserted into the tables that make up the view .

Format ：

create trigger [ Trigger Name ]
on [ View name ]
instead of insert
as
begin
-- Declare variables ;
-- from inserted Find the data of all columns in the table , Assign to the declared variables respectively ;

-- Insert data into the first table with the above data 
-- Use the above data to insert data into the second table 
end

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And we need to know whether this view is a simple view or a complex view , You need to look at the view creation statement .

2. View view created sql Statement also has the following two methods

2.1 The first one is （ Be careful The view name needs to be fully capitalized ）

select dbms_metadata.get_ddl('VIEW', ' View name ') from dual;

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After execution, click the button below to see the statement ：

2.2 The second kind

select text from user_views where view_name = ' View name ';

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The same is true after execution. You need to click the button to see it ：

Okay , Let's share today , Impropriety , I hope you can give me more suggestions .

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