Application of SQL statements related to Oracle table replication

This article describes the SQL statements related to Oracle table replication. This article describes the five types of tables that are frequently used in Oracle table replication SQL, if you are interested in the application of SQL statements related to Oracle table replication, you can browse my article.

As shown in the following figure, Table a is an existing table in the database, and table B is the table to be copied and created based on table:

1. copy only the SQL statements of the Table Structure

 
 

  
  
create table b as select * from a where 1<>1 
 
 

2. SQL statement used to copy the table structure and data in the table

 
 

  
  
create table b as select * from a 
 
 

3. Copy the SQL statement used to create fields in the table

 
 

  
  
create table b as select row_id,name,age from a where 1<>1 
 
 

The premise is that row_id, name, and age are all columns in table.

4. SQL statement used to copy the specified fields and data of the specified fields in the Oracle table

 
 

  
  
create table b as select row_id,name,age from a 
 
 

Although the preceding statements can easily replicate and Create Table B according to the structure of Table a, the index of Table a cannot be copied and must be manually created in table B.

5. insert into saves the query result to an existing table.

 
 

  
  
insert into t2(column1, column2, ....)
 select column1, column2, .... from t1 
 
 

The above content is an introduction to the SQL statements of Oracle copy tables.