ALTER TABLE vs DROP/CREATE statements

Hello Everyone,
I have created a script in order to update our database which includes adding new columns to a table. However, database changes and script generation must now be done using the Erwin data modeler and script generated using a compare option (within Erwin) which compares the model with the actual database.
I had a script of a few lines with a few ALTER TABLE ...ADD COLUMN statements to add the new columns.
Now, in Erwin, instead of generating 'ALTER TABLE...ADD COLUMN statements, Erwin has generated an ALTER TABLE...RENAME and CREATE TABLE statements which as a side effect will drop/re-create the table, all of it's indexes, constraints, foreign keys, etc.
Instead of a few simple "hand written" lines to run a fast script, the script is a few pages long with all of those DROP/CREATE statements, which makes the script way too much complicated and takes much longer to run.
And this, even though the Erwin option "USE ALTER TABLE ADD COLUMN" statement to create columns.
I was told that the DROP/CREATE is normal and that this is the way it should be done.
Am I out of it by thinking that it should use ALTER TABLE ADD COLUMN statements to add new columns to a table and not the DROP/CREATE methodology ? Am I missing something ? Do these new "data thinkers" know something that I am missing ?
Makes me think of the 80s when people were generating dBase application with the included application generator and were ending up with all kinds of useless and non efficient code.
Any though on this ? Am I out in the field ?
Thank you.

Thank you both for your replies.
Neil,
I didn't think that adding new blank columns using the ALTER TABLE ADD COLUMN statement would make the table more fragmented than it already was to begin with.
I would have think that this kind of maintenance would take place on it's own, outside of a new deployment release.
I have always used the ALTER TABLE ADD COLUMN instead of the DROP/CREATE TABLE statements to add new columns to a table because of the simplicity, speed and lower risk involved compare to dropping a table and all of it's objects then re-create all of them and doing an import.
What do any of you do when you need to add new columns to a table ? Use the drop table and re-create or the ALTER TABLE ADD COLUMN ?
Any comments welcome.
Thanks again.

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Alter table tablename drop column col

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Hi,
I am looking for some detailed info regarding the below previleges
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I got the answer for my second question, I have an option to grant 'Alter ANY table' privilege to the user.Yes, but you should not do that.
Regarding question one, Suppose I have two schemas A and B and I want Schema A to have alter table privilege on all tables of Schema B.
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Hi,
Is it necessary to put the a commit after the following statement or is it automatically committed:
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Thanks

Khurram,
Isnt Eric you are , i mean isnt yours synonym :)Erm...simple answer. No. We are not the same person. I just know that Eric, like yourself, makes good contributions to these threads and then someone like that is coming on the forums and trying to make himself look better and put down the regular contributors which isn't really on is it, I think you'll agree.
CREATE PUBLIC SYNONYM Eric FOR Blushadow;
hehe.

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Hi,
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CREATE TABLE privilege grants complete control on owner's tables :
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Hi:
Version 3.1.0.691 on Windows 7 Enterprise 64-bit SP1
I'm trying to import a DDL file with syntax similar to what's below. The <name> notes that I've replaced the actual names for obfuscation purposes.; the real names are in the script.
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RENAME CONSTRAINT SYS_C0041150
TO <name2>_CK;
ALTER TABLE <name>
RENAME CONSTRAINT AVCON_1281559518_ACTIV_022
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Oracle SQL Developer Data Modeler 3.1.0.691
Oracle SQL Developer Data Modeler Import Log
Date and Time: 2012-01-13 16:29:05 PST
Design Name: <name>
RDBMS : Oracle Database 11g
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          Imported Statements:      0
          Failed Statements:           0
          Not Recognized Statements:      819
<<<<< Not Recognized >>>>>
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RENAME CONSTRAINT SYS_<name>
TO <name2>_CK
ALTER TABLE <name>
RENAME CONSTRAINT AVCON_1281559518_QVI_A_000
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Doc

Hi:
The file was indeed comprised of just alter statements. As a test, I trimmed the file down to just one alter statement:
ALTER TABLE <name> RENAME CONSTRAINT SYS_C0041413 TO <name2>_CK;
The output file contained exactly the following, where the <<BEGIN OF FILE>> and <<END OF FILE>> were simply added here for clarity. There was no section called
<<<<< ERRORS >>>>> and the ddl file contained no create table statements.
<<BEGIN OF FILE>>
Oracle SQL Developer Data Modeler 3.1.0.691
Oracle SQL Developer Data Modeler Import Log
Date and Time: 2012-01-16 10:16:42 PST
Design Name: <name>
RDBMS : Oracle Database 11g
          All Statements:           1
          Imported Statements:      0
          Failed Statements:           0
          Not Recognized Statements:      1
<<<<< Not Recognized >>>>>
ALTER TABLE <name> RENAME CONSTRAINT SYS_C0041413 TO <name2>_CK
<<END OF FILE>>
Other info.
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DROP CONSTRAINT SYS_C0041413
ALTER TABLE <name>
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That last line should have read as follows due to the constraint_name I added for it in DM.
ALTER TABLE <name>
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In the example directly above, <name2>_CK is the name I explicity set via DM and would have expected the compare to have used to recreated the constraint since it referenced the target constraint name when it constructed the drop constraint syntax.
I believe at least one bug is involved here, most likely two.
The first bug is that model imports are not capturing not null check constraint names.
The second bug is that the source constraint name is not being used when generating the ddl necessary to change the not null constraint name in the target model.
All of this is assuming that I haven't just goofed and forgotten to check a box somewhere telling it to do what I've been talking about here. :-)
Doc

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2 /
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alter table test_1 modify (col1 clob)
ERROR at line 1:
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SQL> Edited by: AP on Aug 24, 2010 7:41 AM

Cannot ALTER TABLE

I cannot alter tables that I created, add and modify give me a
syntax error. How can this be? Does anyone have anything
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null

Ranga Rao (guest) wrote:
: David Kachuck (guest) wrote:
: : I cannot alter tables that I created, add and modify give me
a
: : syntax error. How can this be? Does anyone have anything
: : positive to say about Personal Oracle Lite?
: Mr David,
: Please give me details about the problem and what exactly the
: message is?
: --Ranga Rao V.
1 alter table title_copy
2* modify (customer varchar2(30));
SQL> /
alter table title_copy
ERROR at line 1:
OCA-30021: error preparing/executing SQL statement
[POL-5228] syntax error
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How to alter table in sql server2008

Hi Friends, I have import one table and want to alter table. How do i do this

Hi ,
YOu need Alter Command for the same. but you have to specify what you want to Alter.
For Reference
To add a column in a table, use the following syntax:
ALTER TABLE table_name
ADD column_name datatype
To delete a column in a table, use the following syntax (notice that some database systems don't allow deleting a column):
ALTER TABLE table_name
DROP COLUMN column_name
To change the data type of a column in a table, use the following syntax:
ALTER TABLE table_name
ALTER COLUMN column_name datatype
http://www.techonthenet.com/sql/tables/alter_table.php
http://www.tutorialspoint.com/sql/sql-alter-command.htm
Thanks
Please Mark This As Answer or vote for Helpful Post if this helps you to solve your question/problem.

How to check if a constraint existed in the table and drop it?

Hi all,
I want to drop a constraint from a table. I do not know if this constraint already existed in the table. So I want to check if this exists first.
Below is my query:
DECLARE
itemExists NUMBER;
BEGIN
itemExists := 0;
SELECT COUNT(CONSTRAINT_NAME) INTO itemExists
FROM ALL_CONSTRAINTS
WHERE UPPER(CONSTRAINT_NAME) = UPPER('my_constraint');
IF itemExists > 0 THEN
ALTER TABLE my_table DROP CONSTRAINT my_constraint;
END IF;
END;
Here is the error I got when I executed the above query:
ORA-06550: line 11, column 5: PLS-00103: Encountered the symbol "ALTER" when expecting one of the following: ( begin case declare exit for goto if loop mod null pragma raise return select update while with <an identifier> <a double-quoted delimited-identifier> <a bind variable> << continue close current delete fetch lock insert open rollback savepoint set sql execute commit forall merge pipe purge
Please help me with this!
Greatly appreciate!
Khoi Le

Yes, I also tried to put the pl-sql in the Execute Immediate. However, the error still remains
EXECUTE IMMEDIATE 'DECLARE
itemExists NUMBER;
BEGIN
itemExists := 0;
SELECT COUNT(CONSTRAINT_NAME) INTO itemExists
FROM ALL_CONSTRAINTS
WHERE UPPER(CONSTRAINT_NAME) = UPPER('my_constraint');
IF itemExists > 0 THEN
ALTER TABLE my_table DROP CONSTRAINT my_constraint;
END IF;
END';
I execute the above code via running the batch file.
Here is the error after I ran the batch file:
ORA-06550: line 11, column 5:
PLS-00103: Encountered the symbol "ALTER" when expecting one of the following:
( begin case declare exit for goto if loop mod null pragma
raise return select update while with <an identifier>
<a double-quoted delimited-identifier> <a bind variable> <<
continue close current delete fetch lock insert open rollback
savepoint set sql execute commit forall merge pipe purge
The symbol "lock was inserted before "ALTER" to continue.
ORA-06550: line 11, column 53:
PLS-00103: Encountered the symbol "DROP" when expecting one of the following:
. , @ in <an identifier>
<a double-quoted delimited-identifier> partition subpartition
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Difference between alter table statements to add primary keys

Hi,
Can someone explain what the difference between these 2 statements are and if & when one should be used over the other?
Also, are the brackets around the column name necessary?
Thanks!
ALTER TABLE xyz ADD CONSTRAINT id_pk PRIMARY KEY (id);
ALTER TABLE xyz ADD PRIMARY KEY (id);

Hi,
As every one has explained that there is no difference in the actual functioning of the two constraints except that the first statement will create Primary Key constraint with user defined name as id_pk whereas in the second statement Primary key will be created with system generated name like SYS....
Normally name for the constraints are needed when you are working on constraints like need to enable or disable the constraints or need to drop the constraints.
We can say that names for primary key are least required when it comes to the usage except better recognization.
Because we can drop primary key, disable primary key,enable primary key without giving the name for the primary key as there can only be one primary key in the table. So not much an issue with the name.
But as earlier post say its better than nothing,, i will add to it that its almost same as that with names constrained in case of Primary Keys taking into account the usage of the named primary key.
Regards

Create a table from another table and add constraint statement. Please help

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PCTFREE 10 PCTUSED 0 INITRANS 1 MAXTRANS 255 NOCOMPRESS LOGGING STORAGE
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TABLESPACE TAB_DATA
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create table my_table
CONSTRAINT "MY_TEMP" UNIQUE ("ID", "SNAME", "CNAME", "TIME", "SYSTEM_ID")
USING INDEX PCTFREE 10 INITRANS 2 MAXTRANS 255 COMPUTE STATISTICS STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645 PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT) TABLESPACE "TAB_DATA" ENABLE
CLUSTER MY_CLUSTER
"CNAME"
as (select t1, t5, t2, t3, t4 from orig_table;

Hi,
Why do you need to combine the two action togather. You can get the things done in two steps.
Create table tab1 as select * from tab2;
Then you create any contraint that you want to create on tab2 using 'alter table add constraint'.
Regards

Help with drop create and update table

Sir/Madam,
I have joined 5 tables and selected some columns ,then I need to update some columns in that. After updating I need to create a report with the new column values.
To do this my method is to create temp table with the select statement then update the temp table , use this temp table for the report and then drop the temp table.
Is there anyother way to do this ??
Can I create a cursor and update the cursor column ??
Does dynamic sql always be created as procedure ??

Hi,
you need to understand how eventing works in BSP and MVC architecture. Pls refer to the below link for a basic understanding of how BSP works - View, Controller and Model class concepts.
http://www.sapdev.co.uk/webapps/bsp/washome.htm
For your requirement -
1. you need a view on which you will create a drop down list UI element and a table view element
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Reg alter table move statement

Hi friends,
I am having a table with 10GB. i moved the table to the same tablespace using "alter table move" statement.
previously my tablespace had 6 GB freespace. To move the table i resized datafile to increase freespace in tablespace.
after moving, my table size reduced to 8GB. now i want to reduce the datafile size to 6GB again. but its throwing error
ORA-03297: file contains used data beyond requested RESIZE value
Can't i reduce the datafile size to 6GB again?
thanks in advance

resize will not released space below the high water mark.
The simpliest way how to proceed in this case is to move all tables to the new tablespace and drop the original including datafiles. And rename new tablespace back to the old ones name if You want.
You can read some more discussions here:
http://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:766625833673

Table compression and alter table statement

Friends
I am trying to add columns to a table which is compressed. Since Oracle treats compressed tables as Object tables, I cannot add columns directly so I tried to uncompress table first and then add columns. This doesnt seems to work.
What could be issue.
Thanks
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Script to test is here and results are below.
-- Test1 => add columns to uncompressed table -> Success
DROP TABLE TAB_COMP;
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-- Test2 =. try adding columns to compressed tables, uncompress it and then try again -> Fails
DROP TABLE TAB_COMP;
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ALTER TABLE TAB_COMP ADD (NAME VARCHAR2(10));
ALTER TABLE TAB_COMP move NOCOMPRESS;
ALTER TABLE TAB_COMP ADD (NAME VARCHAR2(10));
SQL> -- Test1 => add columns to uncompressed table -> Success
SQL> DROP TABLE TAB_COMP;
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SQL> CREATE TABLE TAB_COMP(ID NUMBER) NOCOMPRESS;
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SQL> ALTER TABLE TAB_COMP ADD (NAME VARCHAR2(10));
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SQL>
SQL> -- Test2 =. try adding columns to compressed tables, uncompress it and then try again -> Fails
SQL> DROP TABLE TAB_COMP;
Table dropped.
SQL> CREATE TABLE TAB_COMP(ID NUMBER) COMPRESS;
Table created.
SQL> ALTER TABLE TAB_COMP ADD (NAME VARCHAR2(10));
ALTER TABLE TAB_COMP ADD (NAME VARCHAR2(10))
ERROR at line 1:
ORA-22856: cannot add columns to object tables
SQL> ALTER TABLE TAB_COMP move NOCOMPRESS;
Table altered.
SQL> ALTER TABLE TAB_COMP ADD (NAME VARCHAR2(10));
ALTER TABLE TAB_COMP ADD (NAME VARCHAR2(10))
ERROR at line 1:
ORA-22856: cannot add columns to object tables

Which version of oracle you are using?
1* create table test1234(a number) compress
SQL> /
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Table altered.
Elapsed: 00:00:00.02

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