I wrote a UNIX batch job which updates a table with some "where" conditions. Before updating those records, i need to take the backup (insert statements) of the records that is returned with the "where conditions" and store it in ".dat" file. Could you please help on this???
The most straightforward way to create a backup of the table would be to use a create table statement using the where condition(s) of your update statement. For example, let's take a sample update statement:
UPDATE sometable
SET field1 = 'value'
WHERE company = 'Oracle'
This update would update the field1 column of every row where the company name is Oracle. You could create a backup of sometable by issuing the following command:
CREATE TABLE sometable_backup AS (SELECT * FROM sometable WHERE company = 'Oracle');
This will create a table called sometable_backup that will contain all of the rows that match the where clause of the update.
You can then use Data Pump or another utility to create an export .dat file of that specific table. You can use that .dat file to import into other databases.
Related
Hi I want to create a csv file using plsql utl file. For that I am creating cursor in utl file but I dont want to enter duplicate data. Because I want to create that csv file daily from the same table. Please help
I tried by cursor but I have no idea how to restrict duplicate entries because I want to create the csv file from same table on daily basis
A cursor selects data; it is its where clause that filters which data it'll return.
Therefore, set it so that it fetches only rows you're interested in. For example, one option is to use a timestamp column which tells when was that particular row inserted into the table. Cursor would then
select ...
from that_table
where timestamp_column >= trunc(sysdate)
to select data created today. It is up to you to set it to any other value you want.
How to compare table data structure.
1. Any table added or deleted.
2. Any column in the tables added or deleted.
So my job is to verify if any table or columns are added/deleted on 1st of every month.
My plan is to run a sql query and take a copy of entire list of tables and it's data type only (NO DATA) and save it in txt file or something and use it as base line, and next month run the same sql query and get the results and compare the file. is it possible? please help with the sql query which can do this job.
This query will give you a list of all tables and their columns for a given user (just replace ABCD in this query for the user you have to audit and providing you have access to all that users tables this will work).
SELECT table_name,
column_name
FROM all_tab_columns
WHERE owner = 'ABCD'
ORDER
BY table_name,
column_id;
This answers your question but I have to agree with a_horse_with_no_name that is not a good way implement change control, most notably because the changes have already happened.
This query is very basic and doesn't give you all the information you'd need to see if a column has changed (or any information about other objects types etc), but then you only asked about additions and deletions of tables and columns and you can compare the output of this script to previous outputs to find the answer to your allotted task.
When I need to change a column into a partition (convert normal column as partition column in hive), I want to create a new table to copy all columns except one. I currently have >50 columns in the original table. Is there any clean way of doing that?
Something like:
CREATE student_copy LIKE student EXCEPT age and hair_color;
Thanks!
You can use a regex:
CTAS using REGEX column spec. :
set hive.support.quoted.identifiers=none;
CREATE TABLE student_copy AS SELECT `(age|hair_color)?+.+` FROM student;
set hive.support.quoted.identifiers=column;
BUT (as mentioned by Kishore Kumar Suthar :
this will not create a partitioned table, as that is not supported with CTAS (Create Table As Select).
Only way I see for you to get your partitioned table is by getting the complete create statement of the table (as mentioned by Abraham):
SHOW CREATE TABLE student;
Altering it to create a partition on the column you want. And after that you can use the select with regex when inserting into the new table.
If your partition column is already part of this select, then you need to make sure it is the last column you insert. If it is not you can exclude that column in the regex and including it as last. Also if you expect several partitions to be created based on your insert statement you need to enable 'dynamic partitioning':
set hive.support.quoted.identifiers=none;
set hive.exec.dynamic.partition=true;
set hive.exec.dynamic.partition.mode=nonstrict;
INSERT INTO TABLE student_copy PARTITION(partcol1) SELECT `(age|hair_color|partcol1)?+.+`, partcol1 FROM student;
set hive.support.quoted.identifiers=column;
the 'hive.support.quoted.identifiers=none' is required to use the backticks '`' in the regex part of the query. I set this parameter to it's original value after my statement: 'hive.support.quoted.identifiers=column'
CREATE TABLE student_copy LIKE student;
It just copies the source table definition.
CREATE TABLE student_copy AS select name, age, class from student;
Target cannot be partitioned table.
Target cannot be external table.
It copies the structure as well as the data
I use below command to get the create statement of existing table.
SHOW CREATE TABLE student;
Copy the result and modify that based on your requirement for new table and run the modified command to get the new table.
I am using CREATE GLOBAL TEMPORARY TABLE script to create a temporary table in the oracle DB but its showing SQL Error: ORA-01031: insufficient privileges. I Want to create a temp table with Read only access. Plz help me out in this.
What we are trying to achieve is:
We have to create a table in the destination database which is always GreenPlum.
In source database(Oracle) we are getting a select query from the USER for example: "select * from ABC A join DEF D on A.Col1=D.col1" then we are creating TEMP TABLE(In case of Oracle) on top of it for example "CREATE GLOBAL TEMPORARY TABLE table101 AS (select * from ABC A join DEF D on A.Col1=D.col1)".
Then using this TEMP table we get the required information from INFORMATION_SCHEMA for example "select * from ALL_TAB_COLUMNS where table_name='table101' ".By this we will get the column_name,data_type,character_maximum_length etc information. Using this information we can get "create table Statement" using Javascript .
Then we store this Create table statement in a variable & run it in Execute Row script(Step in pentaho data integration tool) which will create the Table in the destination DB.
Problem is that we have read only access in oracle. now what to do.
NOTE: In short, we are creating a table in the destination DB using the select statement from the source DB. Means structure of the table in Dest DB depends on the select query in Source DB.
If the target database is also an oracle database then you should be able to set up a database link there to the source database and use a "CREATE TABLE AS SELECT * FROM +source table+#+database link+;"
Whoops, I just noticed that this is from 2014. Oh well, maybe it well help future inquirers.
I want to create a table (lets say table_copy) which has same columns as other table (lets call it table_original) in Oracle database, so the query will be like this :
create table table_copy as (select * from table_original where 1=0);
This will create a table, but the constraints of table_original are not copied to table_copy, so what should be done in this case?
Only NOT NULL constraints are copied using Create Table As Syntax (CTAS). Others should be created manually.
You might however query data dictionary view to see the definitions of constraints and implement them on your new table using PL/SQL.
The other tool that might be helpful is Oracle Data Pump. You could import the table using REMAP_TABLE option specifying the name for the new table.
Use a database tool to extract the DDL needed for the constraints (SQL Developer does the job). Edit the resulting script to match the name of the new class.
Execute the script.
If you need to do this programmatically you can use a statement like this:
DBMS_METADATA.GET_DDL('TABLE','PERSON') from DUAL;