Table t1 is partitioned and has data.
I am using this command to transfer data from t1 to t2:
CREATE TABLE t2
TABLESPACE ts1
AS
select * from t1;
However this copies all the data but does not create partitions as in t1. Is there a command to copy all the data plus partitions and indexes from t1 to t2?
Use dbms_metadata to get the whole structure.
SELECT dbms_metadata.get_ddl( 'TABLE', 'SOURCE_TABLE_NAME' ) FROM DUAL;
Run the DDL generated from this query replacing the table name with new table name.
If your source_table is in a different schema, then
SELECT dbms_metadata.get_ddl( 'TABLE', 'SOURCE_TABLE_NAME', 'SOURCE_SCHEMA_NAME' ) FROM DUAL;
It's not possible in the same schema - it will fail with an object already exists error. If it is a different schema, then try this:
export and import by renaming the table while importing to another schema.
Otherwise try with DBMS_METADATA.GET_DDL.
I want to duplicate a table schema, but only if the target table does not yet exist:
CREATE TABLE IF NOT EXISTS my_table_secondary as select * from my_table_primary
Problem: running this if the my_secondary_table exists results in:
ERROR: Syntaxerror at "as".
What could I do to make this sql statement work?
(postgres 9.4)
To duplicate the schema of a table, you need a completely different syntax.
create table if not exists my_table_secondary (
like my_table_primary including all
);
INCLUDING ALL is an abbreviated form of INCLUDING DEFAULTS INCLUDING
CONSTRAINTS INCLUDING INDEXES INCLUDING STORAGE INCLUDING COMMENTS.
It doesn't duplicate foreign key constraints. See CREATE TABLE. Search for "The LIKE clause".
Try this approach:
CREATE OR REPLACE VIEW my_view AS SELECT * FROM my_table_primary;
CREATE TABLE IF NOT EXISTS my_table_secondary LIKE my_view;
INSERT INTO my_table_secondary
SELECT * FROM my_view
WHERE NOT EXISTS ( SELECT * FROM my_table_secondary );
More on CREATE TABLE ... LIKE: http://www.postgresql.org/docs/9.1/static/sql-createtable.html
I want to create a table using CTAS of partitioned table.
New table must have all the data and partitions, subpartitions of old table.
How to do this?
You need to first create the new table with all the partitions, there is no way you can add partition definitions to a CTAS. Once the table is created you can populate it using insert into .. select.
You can use dbms_metadata.get_ddl to get the definition of the old table.
select dbms_metadata.get_ddl('TABLE', 'NAME_OF_EXISTING_TABLE')
from dual;
Save the output of that into a script, do a search and replace to adjust the table name, then run the create table and then run the insert into ... select ...
How can I efficiently copy a table within an informix database? I would like to do something like
create table new_table as (select * from old_table)
but that doesn't work.
If you only need a temporary table, then:
SELECT * FROM old_table INTO TEMP new_table;
If you need a permanent table, then there isn't (yet) a simple way to do it. You have to determine the schema of the old table, use it to create the new table, then use:
INSERT INTO new_table SELECT * FROM old_table;
The fiddly bit is determining the schema of the old table. dbschema -d database -t old_table more or less provides the information you need.
in informix 12.10 you can now
create table newtable as select * from oldtable;
I know the statement:
create table xyz_new as select * from xyz;
Which copies the structure and the data, but what if I just want the structure?
Just use a where clause that won't select any rows:
create table xyz_new as select * from xyz where 1=0;
Limitations
The following things will not be copied to the new table:
sequences
triggers
indexes
some constraints may not be copied
materialized view logs
This also does not handle partitions
I used the method that you accepted a lot, but as someone pointed out it doesn't duplicate constraints (except for NOT NULL, I think).
A more advanced method if you want to duplicate the full structure is:
SET LONG 5000
SELECT dbms_metadata.get_ddl( 'TABLE', 'MY_TABLE_NAME' ) FROM DUAL;
This will give you the full create statement text which you can modify as you wish for creating the new table. You would have to change the names of the table and all constraints of course.
(You could also do this in older versions using EXP/IMP, but it's much easier now.)
Edited to add
If the table you are after is in a different schema:
SELECT dbms_metadata.get_ddl( 'TABLE', 'MY_TABLE_NAME', 'OTHER_SCHEMA_NAME' ) FROM DUAL;
create table xyz_new as select * from xyz where rownum = -1;
To avoid iterate again and again and insert nothing based on the condition where 1=2
Using sql developer select the table and click on the DDL tab
You can use that code to create a new table with no data when you run it in a sql worksheet
sqldeveloper is a free to use app from oracle.
If the table has sequences or triggers the ddl will sometimes generate those for you too. You just have to be careful what order you make them in and know when to turn the triggers on or off.
You can do this
Create table New_table as select * from Old_table where 1=2 ;
but be careful
The table you create does not have any Index, PK and so on like the old_table.
DECLARE
l_ddl VARCHAR2 (32767);
BEGIN
l_ddl := REPLACE (
REPLACE (
DBMS_LOB.SUBSTR (DBMS_METADATA.get_ddl ('TABLE', 'ACTIVITY_LOG', 'OLDSCHEMA'))
, q'["OLDSCHEMA"]'
, q'["NEWSCHEMA"]'
)
, q'["OLDTABLSPACE"]'
, q'["NEWTABLESPACE"]'
);
EXECUTE IMMEDIATE l_ddl;
END;
Simply write a query like:
create table new_table as select * from old_table where 1=2;
where new_table is the name of the new table that you want to create and old_table is the name of the existing table whose structure you want to copy, this will copy only structure.
SELECT * INTO newtable
FROM oldtable
WHERE 1 = 0;
Create a new, empty table using the schema of another. Just add a WHERE clause that causes the query to return no data:
WHERE 1 = 0 or similar false conditions work, but I dislike how they look. Marginally cleaner code for Oracle 12c+ IMHO is
CREATE TABLE bar AS
SELECT *
FROM foo
FETCH FIRST 0 ROWS ONLY;
Same limitations apply: only column definitions and their nullability are copied into a new table.
If one needs to create a table (with an empty structure) just to EXCHANGE PARTITION, it is best to use the "..FOR EXCHANGE.." clause. It's available only from Oracle version 12.2 onwards though.
CREATE TABLE t1_temp FOR EXCHANGE WITH TABLE t1;
This addresses 'ORA-14097' during the 'exchange partition' seamlessly if table structures are not exactly copied by normal CTAS operation. I have seen Oracle missing some of the "DEFAULT" column and "HIDDEN" columns definitions from the original table.
ORA-14097: column type or size mismatch in ALTER TABLE EXCHANGE
PARTITION
See this for further read...
you can also do a
create table abc_new as select * from abc;
then truncate the table abc_new. Hope this will suffice your requirement.
Using pl/sql developer you can right click on the table_name either in the sql workspace or in the object explorer, than click on "view" and than click "view sql" which generates the sql script to create the table along with all the constraints, indexes, partitions etc..
Next you run the script using the new_table_name
copy without table data
create table <target_table> as select * from <source_table> where 1=2;
copy with table data
create table <target_table> as select * from <source_table>;
In other way you can get ddl of table creation from command listed below, and execute the creation.
SELECT DBMS_METADATA.GET_DDL('TYPE','OBJECT_NAME','DATA_BASE_USER') TEXT FROM DUAL
TYPE is TABLE,PROCEDURE etc.
With this command you can get majority of ddl from database objects.
Create table target_table
As
Select *
from source_table
where 1=2;
Source_table is the table u wanna copy the structure of.
create table xyz_new as select * from xyz;
-- This will create table and copy all data.
delete from xyz_new;
-- This will have same table structure but all data copied will be deleted.
If you want to overcome the limitations specified by answer:
How can I create a copy of an Oracle table without copying the data?
The task above can be completed in two simple steps.
STEP 1:
CREATE table new_table_name AS(Select * from old_table_name);
The query above creates a duplicate of a table (with contents as well).
To get the structure, delete the contents of the table using.
STEP 2:
DELETE * FROM new_table_name.
Hope this solves your problem. And thanks to the earlier posts. Gave me a lot of insight.