Summary of Oracle query statement Application Experience

The following articles mainly describe the practical application experience of Oracle query statements. If you are interested in the actual application of Oracle query statements, you can click the following articles to view them. I hope it will help you in this regard.

1. select * from table_name where rownum> begin and rownum <end

2. SQL = "select * from table"

 
 

  
  
con.prepareCall("SELECT * FROM(SELECT A.*, rownum r FROM("+sql+") A WHERE rownum <=  
  
  
"+intPage*intPageSize+") B WHERE r > "+(intPage-1)  
  
  
*intPageSize);  
 
 

Today, I want to query all the table names under the OOracle database or all the tables under a user. I haven't thought about it for a long time. I still found the answer online.

 
 

  
  
select table_name from all_tables; 
 
 

All

 
 

  
  
select table_name from user_all_tables; 
 
 

All tables of a user in an Oracle query statement

The following is a post on the SQL statement.

Select * from user_objects; // query all tables

Select * from dba_tables; // query all tables

Select * from all_tables; // query all tables

Select * from user_users // find a user

Select * from all_users // query all users

Select * from dba_users // query all users

Select name, dbid from v $ database; // query the database name and its ID

Select * from sys. user_tab_columns; // query the table name and display the column name.

Describe table name // query the table structure

Select * from sys. user_tab_columns where table_name = table name

Queries the fields of a specified table name.

2: query database Parameters

 
 

  
  
show parameter db; 
 
 

3: The instance name of the database queried by the Oracle query statement.

 
 

  
  
select instance_name from v$instance; 
 
 

4: Database Domain Name

After the database is installed, you can use

 
 

  
  
select value from v$parameter where name='db_domain' 
  
  
show parameter domain  
 
 

5: Database Service name

If the database has a domain name, the Database Service name is the global database name. If no domain name is defined for the database, the Database Service name is the same as the database name.

 
 

  
  
show parameter service_name 
 
 

6: display the current user

 
 

  
  
show user 
 
 

7: Direct Login

 
 

  
  
sqlplus "/as sysdba" 
 
 

8: Current OOracle system time

 
 

  
  
select sysdate from dual; 
 
 

9: query the database dictionary v $ nls_parameter to view character set parameters

 
 

  
  
select * from v$nls_parameters;  
 
 

The above content is an introduction to the Oracle query statement book. I hope you will have some gains.