I am using XMLType column in some of my oracle database table. Earlier(in 11.2.0.2) the default storage type considered is CLOB. So If you issue a query for the XMLType columns, I can see the content of the column as XML string. But when I drop and re-create all the tables and inserted some data, I could not get the content of the XMLType columns. It simpley display the XMLType in the cloumn value. I have a doubt that whether the storage type is chaged in BINARY XML? So I issue the following alter statement:
ALTER TABLE "MYSCHEMA"."SYSTEMPROP"
MODIFY ("XMLCOL")
XMLTYPE COLUMN "XMLCOL" STORE AS CLOB;
Please note that there are already some data present in the table. Event after when I delete and insert a row, the content is showing as XMLType. I am using SQL developer UI tool. Can anybody suggest a way to fix this issue?
Edit:
Ok, Now we have decided that we will store the XMLType column content as SECURE FILE BINARY XML. So we have table like this:
CREATE TABLE XMYTYPETEST
(
ID NUMBER(8) NOT NULL,
VID NUMBER(4) NOT NULL,
UserName VARCHAR2(50),
DateModified TIMESTAMP(6),
Details XMLType
)XMLTYPE COLUMN Details STORE AS SECUREFILE BINARY XML;
Insert into XMYTYPETEST values(10001,1,'XXXX',sysdate,'<test><node1>BLOBTest</node1></test>');
Select * from XMYTYPETEST;
The XMLType colum is displayed as "SYS.XMLType" in sql developer. So how to get the content of the binary XML?
Edit:
SELECT x.ID,x.Vid, x.details.getCLOBVal() FROM XMYTYPETESTx where x.ID=100000;
The above query works out for me finally.
The underlying storage for xmldata inside oracle database is either CLOB or Binary.
And it defaults to Binary storage in 11g.
But irrespective of the storage, your queries on the xmltype column should yield you consistent results.
>>>> So how to get the content of the binary XML?
The way to get the content of an xmltype column using queries does not change.
select xmlquery(..)
select xmlcast(xmlquery(...))
select extract(), extractValue(), ...
These are some of the ways data within xml is extracted.
Hope this helps.
Related
I have a partitioned external Hive table. It has data loaded from parquet files. I have a few columns in that table that require a datatype change (TIMESTAMP -> STRING). Currently, when you query these columns, it returns NULL values because of the wrong data-type.
I ran ALTER TABLE table_name CHANGE col_1 col_1 STRING; to successfully change the datatype for that column to STRING, but when I query the table again, the data in that table is still showing NULL. Is there a way to update the data without dropping the partitions and re-loading the data from scratch?
There is a table with a XMLTYPE column (NOT NULL), XML (string) can be inserted using SQLPLUS but SQL Developer inserts 'null' when XML is loaded from a file.
There is a workaround:- Set XMLTYPE column nullable
, insert null first time , COMMIT and insert XML after that.
I have to copy data from one table to another which one table is in Oracle and one is in MSSQL Server. I want to copy the data from MSSQL Server table to Oracle table. The problem is that the MSSQL Server table has one column which is of data type ntext and the destination column in Oracle table is clob.
When I use the query
insert into oracle.table select * from sqlserver.table#mssql; I get the following error:
SQL Error: ORA-00997: illegal use of LONG datatype
Can anyone advice on this please?
I tried it through a PL/SQL Procedure and it worked. I created a cursor, passed in the values to my variables declared in VARCHAR2 and then run an EXECUTE IMMEDIATE for the INSERT INTO....SELECT * FROM <TABLE_NAME>#MSSQL.
I have an encountered an issue where the data I was trying to store in my varchar2(4000) column was too big, so I wish to change the column to one more suitable for storing large amounts of textual data. Specifically, a serialized array.
Firstly, is CLOB the best data type for me to use for this purpose? Is there a more appropriate data type?
Secondly, when I try to alter the column using the usual snyntax:
ALTER TABLE table MODIFY column CLOB
I get the following error: ORA-22858: invalid alteration of datatype
What's the most straightforward way to alter this table without losing any data?
The most straightforward way, given that the operation of moving from a varchar column to a CLOB is disallowed, would be to create a new column and move the data from the old column to the new column:
ALTER TABLE some_table ADD (foo CLOB);
UPDATE some_table SET foo = old_column;
ALTER TABLE some_table DROP COLUMN old_column;
ALTER TABLE some_table RENAME COLUMN foo TO old_column;
The VARCHAR2 column cannot be directly converted to CLOB but it can be done in 2 steps:
Convert column datatype from VARCHAR2 to LONG.
Convert column datatype from LONG to CLOB.
ALTER TABLE table MODIFY column long;
ALTER TABLE table MODIFY column clob;
For Oracle 11g:
ALTER TABLE table MODIFY column long;
ALTER TABLE table MODIFY column clob;
I'm trying to update some existing code that is supposed to write data to a variety of Databases (SQL, Access, Oracle) via ODBC, but I'm having a few problems with Oracle and am looking for any suggestions.
I've set my Oracle database up using a Trigger (basic tutorial online, which I'd like to support).
CREATE TABLE TABLE1 (
RECORDID NUMBER NOT NULL PRIMARY KEY,
ID VARCHAR(40) NULL,
COUNT NUMBER NULL
);
GO
CREATE SEQUENCE TABLE1_SEQ
GO
CREATE or REPLACE TRIGGER TABLE1_TRG
BEFORE INSERT ON TABLE1
FOR EACH ROW
WHEN (new.RECORDID IS NULL)
BEGIN
SELECT TABLE1_SEQ.nextval
INTO :new.RECORDID
FROM dual;
end;
GO
I then populate a DataTable using a SELECT * FROM TABLE1. The first problem is that this DataTable doesn't know that the RecordId column is auto-generated. If I have data in my table then I can't alter it because I get a error
Cannot change AutoIncrement of a DataColumn with type 'Double' once it
has data.
If I continue, ignoring this, then I quickly get stuck. If I create a new DataRow and try to insert it, I can't set RecordID to DBNull.Value because it complains that the column has to be non-null (NoNullAllowedException). I can't however generate a value myself, because I don't know what value I should be using really, and don't want to screw up the trigger by using the next available value.
Any suggestions on how I should insert data without ODBC complaining?
It does not appear that your first problem is with an Oracle database. There is no such thing as an "Autoincrement" column in Oracle. Are you sure that message is coming from an Oracle database?
With Oracle, you should be able to provide any dummy value on insert for the primary key, and the trigger will overwrite it.
There is also nothing in your provided description that would prevent you from updating this value in Oracle (since your trigger is on insert only) unless you have foreign key references to the key.