Is there a DB2 v9.1 equivalent for sp_rename?
It depends on the object.
For tables and indexes, you can use the RENAME sql statement.
If you want to rename a column, you can use ALTER TABLE ... RENAME COLUMN.
For other objects, you probably have to drop and recreate it.
Hope that helps.
Related
I would like to rename a column in DB2 on the iSeries platform. The link below is related, however, I do not have a primary key or constraint defined on the columns I would like to rename. In addition, I'm not certain that they are on the iSeries as well.
Rename column in DB2
However, I decided to give it a go with the following statement:
ALTER TABLE MYLIB.MYFILE RENAME COLUMN COL0001 TO COL0002;
Post execution, I am given the following warning:
Additionally, I do not see a RENAME COLUMN in the docs:
https://www.ibm.com/support/knowledgecenter/en/ssw_ibm_i_71/db2/rbafzatabl.htm
Is this something that is not possible on V7R1 DB2?
There is no RENAME COLUMN clause in the ALTER TABLE statement in DB2 for IBM i.
You may probably achieve the same with the following:
ALTER TABLE MYLIB.MYFILE ADD COLUMN COL0002 ...;
UPDATE MYLIB.MYFILE SET COL0002 = COL0001;
ALTER TABLE MYLIB.MYFILE DROP COLUMN COL0001;
It's been a while.
Using DB2 10 for z/OS, I've been asked to change a specific column in a table from decimal(7,2) to decimal(7,4). Sounds easy, right?
alter table MySchema.MyTable
alter column myColumn
set data type decimal(7,4);
But, DB2 responds with this error: "Attributes specified for column 'MYCOLUMN' are incompatible with existing column definition."
I had thought that converting from decimal(7,2) to decimal(7,4) would be pretty straightforward, but DB2 disagrees.
Outside of dropping the table and recreating it from scratch, what alternatives do I have?
Thanks in advance!
Dave
The reason Db2 doesn't like that change is you're going from from 99999.99 to 999.9999
Is that really what you want? Going from (7,2) to (9,4) would just add two more decimal places without losing any data and should be allowed by the Db.
Db2 for i gives a warning, but allows you to ignore the warning...
Create a new column ALTER ADD COLUMN of the right type, use an UPDATE to populate it, ALTER DROP COLUMN the old column. RENAME COLUMN so set the name of the original column.
I am trying to rename a table in db2 like so
rename table schema1.mytable to schema2.mytable
but getting the following error message:
the name "mytable" has the wrong number of qualifiers.. SQLCODE=-108,SQLSTATE=42601
what is the problem here.... I am using the exact syntax from IBM publib documentation.
You cannot change the schema of a given object. You have to recreate it.
There are severals ways to do that:
If you have only one table, you can export and import/load the table. If you use the IDX format, the DDL will be included in the generated file. If using another format, the table has be created.
You can recreate the table by using:
Create table schema2.mytable like schema1.mytable
You can extract the DDL with the db2look tool
If you are changing the schema name for a schema given, you can use ADMIN_COPY_SCHEMA
These last two options only create the table structure, and you still need to import the data. After having create the table, you insert the data by different ways:
Inserting directly
insert into schema2.mytable select * from schema1.mytable
Via load from cursor
Via a Load or import from file (The file exported in the previous step)
The problem is the foreign relations, because they have to be recreated.
Finally, you can create an alias. It is easier, and you do not have to deal with relations.
You can easily rename a table with this statement:
RENAME TABLE SCHEMA.TABLENAME TO NEWTABLENAME;
You're not renaming table in provided example, you're trying to move to different schema, it's not the same thing. Look into db2move tool for this.
if you want to rename a table in the same schema, you can use like this.
RENAME TABLE schema.table_name TO "new_table_name";
Otherwise, you can use tools like DBeaver to rename or copy tables in a db2 db.
What if you leave it as is and create an alias with the new name and schema.
Renaming a table means to rename a table within same schema .To rename in other schema ,db2 call its ALIAS:
db2 create alias for
When I alter a table in db2, I have to reorganize it
so I execute the next query:
Call Sysproc.admin_cmd ('reorg Table myTable');
I m searching an appropriate solution to reorganize a table when it s altered, or reorganize all the schema after making various modifications
You can determine when tables will require a REORG by looking at SYSIBMADM.ADMINTABINFO:
select tabschema, tabname
from sysibmadm.admintabinfo
where reorg_pending = 'Y'
You may also want to look at the NUM_REORG_REC_ALTERS column as this may show you additional tables that don't require reorganization due to various ALTER TABLE statements.
The reorg operation is similar to a defrag in hard disk. It frees empty spaces in pages, and eventually it could reorganize data according to an index. Depending on the features, it creates the compression dictionary and compress data.
As you can see, reorg operation is an administrative task, and it is not necessary each time data is modified. A database could run without reorg.
It order to ease this, DB2 included autonomic features like automatic backup, however this doesn't answer you own question. This will only trigger reorg on tables that need that.
To reorg a table explicitly you need to execute the command reorg http://publib.boulder.ibm.com/infocenter/db2luw/v10r1/topic/com.ibm.db2.luw.admin.cmd.doc/doc/r0001966.html
or via the admin_cmd http://publib.boulder.ibm.com/infocenter/db2luw/v10r1/topic/com.ibm.db2.luw.sql.rtn.doc/doc/r0023582.html
in db2 config we have:
Automatic reorganization (AUTO_REORG) = OFF
we can set auto_reorg to on
How to delete all the records in SQL Server 2008?
To delete all records from a table without deleting the table.
DELETE FROM table_name use with care, there is no undo!
To remove a table
DROP TABLE table_name
from a table?
You can use this if you have no foreign keys to other tables
truncate table TableName
or
delete TableName
if you want all tables
sp_msforeachtable 'delete ?'
Use the DELETE statement
Delete From <TableName>
Eg:
Delete from Student;
I can see the that the others answers shown above are right, but I'll make your life easy.
I even created an example for you. I added some rows and want delete them.
You have to right click on the table and as shown in the figure Script Table a> Delete to> New query Editor widows:
Then another window will open with a script. Delete the line of "where", because you want to delete all rows. Then click Execute.
To make sure you did it right right click over the table and click in "Select Top 1000 rows". Then you can see that the query is empty.
If you want to reset your table, you can do
truncate table TableName
truncate needs privileges, and you can't use it if your table has dependents (another tables that have FK of your table,
For one table
truncate table [table name]
For all tables
EXEC sp_MSforeachtable #command1="truncate table ?"
Delete rows in the Results pane if you want to delete records in the database. If you want to delete all of the rows you can use a Delete query.
Delete from Table_name
delete from TableName
isn't a good practice.
Like in Google BigQuery, it don't let to use delete without "where" clause.
use
truncate table TableName
instead
When the table is very large, it's better to delete table itself with drop table TableName and recreate it, if one has create table query; rather than deleting records one by one, using delete from statement because that can be time consuming.
The statement is DELETE FROM YourDatabaseName.SomeTableName; if you are willing to remove all the records with reasonable permission. But you may see errors in the constraints that you defined for your Foreign Keys. So that you need to change your constraints before removing the records otherwise there is a command for MySQL (which may work for others) to ignore the constraints.
SET foreign_key_checks = 0;
Please be aware that this command will disable your foreign keys constrain check, so this can be dangerous for the relationships you created within your schema.