I want to use LOOP to go trough all partitions in a table to change some data per partitions.
I am starting like:
BEGIN
FOR n in (here is the select statement which chooses the partition names)
LOOP
UPDATE table_name
PARTITION (n)
SET
here are columns to change with new values;
COMMIT;
END LOOP;
END;
I get error ORA 02149 and ORA 06512 that partition does not exist.
Is it related to some declaration? How I should solve it?
Why bother with a partition name? What benefit do you expect? Simply
update table_name set
col1 = ...,
col2 = ...
where condition_goes_here --> this condition will "determine" the partition
You can use execute immediate and user_tab_partitions data dictionary view together as
Begin
for c in ( select *
from user_tab_partitions p
where p.table_name = 'TABLE_NAME'
order by p.partition_position )
loop
execute immediate 'update '||c.table_name||' partition('||c.partition_name||')
set col1 = ''xYz'' ';
commit;
end loop;
End;
Related
I need to take the count from multiple tables(1000+ Tables) and Sum up the same into a single value.
For example: Tables starting with TA .. Only these tables needs to be considered.
I want the actual counts and hence dont want to use DBA_TABLES/ALL_TABLES.
Please suggest me the best way to do this. I just need the single value of Sum of all the records in those tables.
Thanks
An example:
CREATE TABLE TA_1 AS select * FROM all_objects;
CREATE TABLE TA_2 AS select * FROM TA_1;
CREATE TABLE TA_abcd AS select * FROM TA_1;
select count(*) FROM TA_1;
COUNT(*)
----------
73701
DECLARE
partial_cnt NUMBER;
final_cnt NUMBER := 0;
BEGIN
FOR tab_name IN ( SELECT table_name FROM user_tables WHERE table_name LIKE 'TA%' )
LOOP
EXECUTE IMMEDIATE 'SELECT count(*) FROM '|| tab_name.table_name INTO partial_cnt;
final_cnt := final_cnt + partial_cnt;
END LOOP;
DBMS_OUTPUT.PUT_LINE( 'Total count = ' || final_cnt );
END;
/
Total count = 221103
From table1 I would like to gather values from certain columns. First of all I have tried to copy one table to another but I stuck when tried to:
for row in row_count
for column in column_count
insert into table2 at (x,y) value from (row,column)
column++
end
row++
end
My first function to count how many rows is:
create or replace FUNCTION func_count_rows(table_name IN varchar2,
debug boolean default false)
RETURN number IS
total number(2) := 0;
BEGIN
IF debug = true THEN
DBMS_OUTPUT.put('Function count rows: ');
DBMS_OUTPUT.PUT_LINE('select count(*) from ' || table_name || ';');
DBMS_OUTPUT.put('Returns: ');
DBMS_OUTPUT.PUT_LINE('');
END IF;
execute immediate 'select count(*) from ' || table_name into total;
RETURN total;
END;
Then my procedure to first print values but I stuck here:
create or replace procedure gather_values (rows_quantity in VARCHAR2,
column_count in VARCHAR2,
debug boolean default false
)
is begin
select
FOR i IN 1..rows_quantity LOOP
DBMS_OUTPUT.PUT_LINE('#### ROW 1 ####');
FOR i IN 1..94 LOOP
END LOOP;
END LOOP;
end;
I don't know how to get column quantity and value from exact (x,y) of table.
Could you kindly help me? Thank you.
I have forget to tell that I'm using oracle SQL enviroment.
First of all, this has nothing in common with PL/SQL:
for row in row_count
for column in column_count
insert into table2 at (x,y) value from (row,column)
column++
end
row++
end
See documentation here.
To copy all rows from one table to another:
insert into table2 (x,y)
select a, b
from table1;
It is a simple SQL query, it can be used as is or inside a PL/SQL procedure.
There is a lot of possibilities to iterate all rows of a table. The most simple:
for i in (select column1, column2, ... from table1) loop
dbms_output.put_line(i.column1);
end loop;
Another ways:
Using cursors
Using collections
Using dynamic SQL and dbms_sql package
To count rows in a table, you can use SQL query:
select count(*)
from table1
or almost the same PL/SQL code (you don't need to use execute immediate):
declare
total number;
begin
select count(*)
into total
from table1;
dbms_output.put_line('count of rows: ' || total);
end;
/
But in any case you don't need to know, how many rows and columns a table contains, to iterate them. You need only to know, how to filter, which of them you want to iterate.
I need to create a table if it does not exist, and when it is created add a single row to it.
I'm new to oracle and PL/SQL so I basically need an equivalent of the following T-SQL:
IF OBJECT_ID('my_table', 'U') IS NULL
BEGIN
CREATE TABLE my_table(id numeric(38,0), date datetime)
INSERT INTO my_table
VALUES (NULL, 0)
END
if you want to check table creation
DECLARE count NUMBER;
BEGIN
count := 0;
SELECT COUNT(1) INTO count from user_tables WHERE table_name= 'MY_TABLE';
IF COL_COUNT = 0 THEN
EXECUTE IMMEDIATE 'create table ....';
END IF;
END;
/
A checking for DML .please note you have to sepcify your pk columns and values.
DECLARE count NUMBER;
BEGIN
count := 0;
SELECT COUNT(1) INTO count from MY_TABLE WHERE id= 0 and name='Something';
IF COL_COUNT = 0 THEN
EXECUTE IMMEDIATE 'insert into MY_TABLE (id,name) values(0,''something'') ';
END IF;
END;
/
also note I recomand to specify columns when you insert into a table
Another approach is to use exception logic. I changed field names and types according to Oracle rules
declare
eAlreadyExists exception;
pragma exception_init(eAlreadyExists, -00955);
begin
execute immediate 'CREATE TABLE my_table(id number, dateof date)';
execute immediate 'INSERT INTO my_table VALUES (NULL, sysdate)';
exception when eAlreadyExists then
null;
end;
but may be it is not a good idea to create tables dynamically
In my opinion, you should not be creating objects on the fly. You should think about your design before implementing it.
Anyway, if you really want to do it this way, then you need to do it programmatically in PL/SQL (ab)using EXECUTE IMMEDIATE.
However, I would prefer the CTAS i.e. create table as select if you want to create a table ta once with a single row. For example,
SQL> CREATE TABLE t AS SELECT 1 id, SYSDATE dt FROM DUAL;
Table created.
SQL> SELECT * FROM t;
ID DT
---------- ---------
1 29-MAY-15
SQL>
The table is created permanently.
If you are looking for a temporary table, which you could use to store session specific data , then look at creating Global temporary table.
From documentation,
Use the CREATE GLOBAL TEMPORARY TABLE statement to create a temporary
table. The ON COMMIT clause indicates if the data in the table is
transaction-specific (the default) or session-specific
You can use NOT EXISTS with select statement:
IF NOT EXISTS(SELECT 1 FROM my_table) THEN
CREATE TABLE my_table(id NUMBER, date date);
COMMIT;
INSERT INTO my_table(id, date) values (NULL, O);
COMMIT;
END IF;
UPDATE
According to the comment, I cannot use Exist directly in PL/SQL. So this is another way to do it:
begin
select case
when exists(select 1
from my_table)
then 1
else 0
end into l_exists
from dual;
if (l_exists = 1)
then
-- anything
else
EXECUTE IMMEDIATE 'CREATE TABLE my_table(id NUMBER, date date)';
EXECUTE IMMEDIATE 'INSERT INTO my_table(id, date) values (NULL, O)';
end if;
end;
I have a table with 2 varchar2 columns. I have added new number column to existing table to make this column primary key. This table now includes 3 columns. I gave a try to use anonymous block as following:
declare
cnt number;
begin
select nvl(count(*),0) into cnt from sometable;
for i in 1..cnt
loop
update sometable set id=i where i=rownum;
end loop;
end;
Using this anonymous block updates this table unexpectedly.
My solution was to use the following statement:
create table sometablecopy as select row_number() over(order by sometable.col1) as id, sometable.* from sometable;
Nevertheless I am curios why doesn't anonymous block produce expected primary key values with the help of rownum pseudocolumn? It must be rownum related issue.
Rownum is a pseudocolumn. Its assigned to rows as they are returned from the select. So you can't say "select * from my_table where rownum = 42" since the row with rownum=42 hasn't been defined yet, it will vary depending on your select and predicate (and "select * from my_table where rownum = 1" will return a single row, not the "first" row, whatever that would be). You could do something like (untested):
declare
cursor sel_cur is
select rowid as row_id
from my_table
order by orderby_col;
v_ctr pls_integer := 0;
begin
for rec in sel_cur
loop
v_ctr := v_ctr + 1;
update my_table set pk_col = v_ctr where rowid = rec.row_id;
end loop;
commit;
exception
when others then
rollback;
raise;
end;
This assumes you have sufficient rollback to update the entire table.
Hope that helps.
You cannot use ROWNUM like that (see ROWNUM in SQL).
What you could have done is this:
UPDATE sometable SET id = ROWNUM;
I would like to find the distinct CLOB values that can assume the column called CLOB_COLUMN (of type CLOB) contained in the table called COPIA.
I have selected a PROCEDURAL WAY to solve this problem, but I would prefer to give a simple SELECT as the following: SELECT DISTINCT CLOB_COLUMN FROM TABLE avoiding the error "ORA-00932: inconsistent datatypes: expected - got CLOB"
How can I achieve this?
Thank you in advance for your kind cooperation. This is the procedural way I've thought:
-- Find the distinct CLOB values that can assume the column called CLOB_COLUMN (of type CLOB)
-- contained in the table called COPIA
-- Before the execution of the following PL/SQL script, the CLOB values (including duplicates)
-- are contained in the source table, called S1
-- At the end of the excecution of the PL/SQL script, the distinct values of the column called CLOB_COLUMN
-- can be find in the target table called S2
BEGIN
EXECUTE IMMEDIATE 'TRUNCATE TABLE S1 DROP STORAGE';
EXECUTE IMMEDIATE 'DROP TABLE S1 CASCADE CONSTRAINTS PURGE';
EXCEPTION
WHEN OTHERS
THEN
BEGIN
NULL;
END;
END;
BEGIN
EXECUTE IMMEDIATE 'TRUNCATE TABLE S2 DROP STORAGE';
EXECUTE IMMEDIATE 'DROP TABLE S2 CASCADE CONSTRAINTS PURGE';
EXCEPTION
WHEN OTHERS
THEN
BEGIN
NULL;
END;
END;
CREATE GLOBAL TEMPORARY TABLE S1
ON COMMIT PRESERVE ROWS
AS
SELECT CLOB_COLUMN FROM COPIA;
CREATE GLOBAL TEMPORARY TABLE S2
ON COMMIT PRESERVE ROWS
AS
SELECT *
FROM S1
WHERE 3 = 9;
BEGIN
DECLARE
CONTEGGIO NUMBER;
CURSOR C1
IS
SELECT CLOB_COLUMN FROM S1;
C1_REC C1%ROWTYPE;
BEGIN
FOR C1_REC IN C1
LOOP
-- How many records, in S2 table, are equal to c1_rec.clob_column?
SELECT COUNT (*)
INTO CONTEGGIO
FROM S2 BETA
WHERE DBMS_LOB.
COMPARE (BETA.CLOB_COLUMN,
C1_REC.CLOB_COLUMN) = 0;
-- If it does not exist, in S2, a record equal to c1_rec.clob_column,
-- insert c1_rec.clob_column in the table called S2
IF CONTEGGIO = 0
THEN
BEGIN
INSERT INTO S2
VALUES (C1_REC.CLOB_COLUMN);
COMMIT;
END;
END IF;
END LOOP;
END;
END;
If it is acceptable to truncate your field to 32767 characters this works:
select distinct dbms_lob.substr(FIELD_CLOB,32767) from Table1
You could compare the hashes of the CLOB to determine if they are different:
SELECT your_clob
FROM your_table
WHERE ROWID IN (SELECT MIN(ROWID)
FROM your_table
GROUP BY dbms_crypto.HASH(your_clob, dbms_crypto.HASH_SH1))
Edit:
The HASH function doesn't guarantee that there will be no collision. By design however, it is really unlikely that you will get any collision. Still, if the collision risk (<2^80?) is not acceptable, you could improve the query by comparing (with dbms_lob.compare) the subset of rows that have the same hashes.
add TO_CHAR after distinct keyword to convert CLOB to CHAR
SELECT DISTINCT TO_CHAR(CLOB_FIELD) from table1; //This will return distinct values in CLOB_FIELD
Use this approach. In table profile column content is NCLOB. I added the where clause to reduce the time it takes to run which is high,
with
r as (select rownum i, content from profile where package = 'intl'),
s as (select distinct (select min(i) from r where dbms_lob.compare(r.content, t.content) = 0) min_i from profile t where t.package = 'intl')
select (select content from r where r.i = s.min_i) content from s
;
It is not about to win any prizes for efficiency but should work.
select distinct DBMS_LOB.substr(column_name, 3000) from table_name;
If truncating the clob to the size of a varchar2 won't work, and you're worried about hash collisions, you can:
Add a row number to every row;
Use DBMS_lob.compare in a not exists subquery. Exclude duplicates (this means: compare = 0) with a higher rownum.
For example:
create table t (
c1 clob
);
insert into t values ( 'xxx' );
insert into t values ( 'xxx' );
insert into t values ( 'yyy' );
commit;
with rws as (
select row_number () over ( order by rowid ) rn,
t.*
from t
)
select c1 from rws r1
where not exists (
select * from rws r2
where dbms_lob.compare ( r1.c1, r2.c1 ) = 0
and r1.rn > r2.rn
);
C1
xxx
yyy
To bypass the oracle error, you have to do something like this :
SELECT CLOB_COLUMN FROM TABLE COPIA C1
WHERE C1.ID IN (SELECT DISTINCT C2.ID FROM COPIA C2 WHERE ....)
I know this is an old question but I believe I've figure out a better way to do what you are asking.
It is kind of like a cheat really...The idea behind it is that You can't do a DISTINCT of a Clob column but you can do a DISTINCT on a Listagg function of a Clob_Column...you just need to play with the partition clause of the Listagg function to make sure it will only return one value.
With that in mind...here is my solution.
SELECT DISTINCT listagg(clob_column,'| ') within GROUP (ORDER BY unique_id) over (PARTITION BY unique_id) clob_column
FROM copia;