Can someone tell me how I can drop a PROCEDURE in Oracle, but just if it exists ?
DROP PROCEDURE IF EXISTS XYZ;
The above does not work.
If your goal is to eliminate error messages in a script, then you can try
begin
execute immediate 'drop procedure xyz';
exception when others then
if sqlcode != -4043 then
raise;
end if;
end;
/
You can also check dictionary view before:
SELECT * FROM USER_PROCEDURES WHERE PROCEDURE_NAME = 'XYZ'
My solution:
DECLARE
V_NUM NUMBER;
BEGIN
SELECT COUNT(*)
INTO V_NUM
FROM USER_OBJECTS
WHERE OBJECT_NAME = 'XYZ'
AND OBJECT_TYPE = 'PROCEDURE';
IF V_NUM > 0 THEN
EXECUTE IMMEDIATE 'DROP PROCEDURE XYZ';
DBMS_OUTPUT.PUT_LINE('Dropped');
END IF;
END;
/
A complete example:
declare
c int;
begin
select count(*) into c from user_procedures where object_type = 'FUNCTION' and object_name = 'ABC';
if c = 1 then
execute immediate 'DROP FUNCTION ABC';
end if;
end;
Related
I'm trying to put together a procedure, which counts the rows for each PARTITION in a table but I'm getting a syntax error:
Errors: PROCEDURE COUNT_PARTITION
Line/Col: 14/31 PLS-00103: Encountered the symbol "(" when expecting one of the following:
I know this isn't the most efficient way and I can use the num_rows column along with gathering statistics to achieve the same results.
Below is my test CASE. I know the problem is with the construction of the 'cmd' call but I can't seem to get it to work. Any help would be greatly appreciated.
CREATE OR REPLACE PROCEDURE cmd(p_cmd varchar2)
authid current_user
is
BEGIN
dbms_output.put_line(p_cmd);
execute immediate p_cmd;
END;
/
CREATE OR REPLACE PROCEDURE
count_partition(
p_tab varchar2
) authid current_user
is
v_cnt integer;
BEGIN
for cur_rec in (select table_name, partition_name,
partition_position
FROM user_tab_partitions where table_name = p_tab order by partition_position) loop
cmd ('select count(*) /*+ parallel(a,8) */
from ' ||p_tab|| 'PARTITION ' ('||cur_rec.partition_name||')' INTO v_cnt);
DBMS_OUTPUT.PUT_LINE(cur_rec.table_name || ' ' || cur_rec.partition_name || ' ' || v_cnt || ' rows');
end loop;
END;
Created a procedure and wrapper
CREATE OR REPLACE PROCEDURE
count_partition(
p_tab varchar2
) authid current_user
is
sql_stmt varchar2(1024);
row_count number;
cursor get_tab is
select table_name,
partition_name
from user_tab_partitions
where table_name=p_tab;
BEGIN
for get_tab_rec in get_tab loop
BEGIN
sql_stmt := 'select count(*) /*+ parallel(a,4) */ from ' ||get_tab_rec.table_name||' partition ( '||get_tab_rec.partition_name||' )';
--dbms_output.put_line(sql_stmt);
EXECUTE IMMEDIATE sql_stmt INTO row_count;
dbms_output.put_line('Table '||rpad(get_tab_rec.table_name
||'('||get_tab_rec.partition_name||')',50)
||' '||TO_CHAR(row_count)||' rows.');
exception when others then
dbms_output.put_line
('Error counting rows for table '||get_tab_rec.table_name);
END;
END LOOP;
END;
/
BEGIN
FOR cur_r IN(
SELECT TABLE_NAME FROM USER_PART_TABLES
)
LOOP
--DBMS_OUTPUT.put_line('Table '|| cur_r.table_name);
count_partition (cur_r.table_name);
END LOOP;
END;
~~
I need to drop an Oracle table only if it 1) exists AND 2) Is NOT Empty
I wrote this code but if the table does not exist the code does not work:
DECLARE
rec_cnt1 NUMBER :=0;
rec_cnt2 NUMBER :=0;
BEGIN
SELECT COUNT(*) INTO rec_cnt1 FROM ALL_TABLES WHERE TABLE_NAME = 'MyTable';
SELECT num_rows INTO rec_cnt2 FROM USER_TABLES WHERE TABLE_NAME = 'MyTable';
IF rec_cnt1 = 1 THEN
BEGIN
IF rec_cnt2 < 1 THEN
EXECUTE IMMEDIATE 'DROP TABLE MyTable cascade constraints';
END IF;
END;
END IF;
END;
/
What am I doing wrong? Please help.
Many thanks in advance
If you want to drop a table if it exists and empty(as the title of the question states) you could do this as follows:
create or replace procedure DropTableIfEmpty(p_tab_name varchar2)
is
l_tab_not_exists exception;
pragma exception_init(l_tab_not_exists, -942);
l_is_empty number;
l_query varchar2(1000);
l_table_name varchar2(32);
begin
l_table_name := dbms_assert.simple_sql_name(p_tab_name);
l_query := 'select count(*)
from ' || l_table_name ||
' where rownum = 1';
execute immediate l_query
into l_is_empty;
if l_is_empty = 0
then
execute immediate 'drop table ' || l_table_name;
dbms_output.put_line('Table "'|| p_tab_name ||'" has been dropped');
else
dbms_output.put_line('Table "'|| p_tab_name ||'" exists and is not empty');
end if;
exception
when l_tab_not_exists
then dbms_output.put_line('Table "'|| p_tab_name ||'" does not exist');
end;
When you are trying to drop a table, or query a table, which does not exist, Oracle will raise ORA-00942 exception and execution of a pl/sql block halts. We use pragma exception_init statement to associate ORA-00942 exception with our locally defined exception l_tab_not_exists in order to handle it appropriately.
Test case:
SQL> exec droptableifempty('tb_test'); -- tb_test table does not exists
Table "tb_test" does not exist
SQL> create table tb_test(
2 col number
3 );
table TB_TEST created.
SQL> exec droptableifempty('tb_test');
Table "tb_test" has been dropped
As a side note. Before querying num_rows column of [dba][all][user]_tables in order to determine number of rows a table has, you need to gather table statistic by executing dbms_stats.gather_table_stats(user, '<<table_name>>');, otherwise you wont get the actual number of rows.
In PL/SQL it is 'normal' to catch the exception.
If it is the correct exception then continue with the next part of your code.
DECLARE
rec_cnt1 NUMBER :=0;
rec_cnt2 NUMBER :=0;
BEGIN
SELECT COUNT(*) INTO rec_cnt1 FROM ALL_TABLES WHERE TABLE_NAME = 'MyTable';
SELECT num_rows INTO rec_cnt2 FROM USER_TABLES WHERE TABLE_NAME = 'MyTable';
IF rec_cnt1 = 1 THEN
BEGIN
IF rec_cnt2 < 1 THEN
EXECUTE IMMEDIATE 'DROP TABLE MyTable cascade constraints';
END IF;
END;
END IF;
EXCEPTION
DBMS_OUTPUT.PUT_LINE('OH DEAR AN EXCEPTION WAS THROWN DUE TO' || SQLERRM);
DBMS_OUTPUT.PUT_LINE('THE ORACLE CODE IS ' || SQLCODE);
-- if it is the oracle code for no such table, or no data selected
-- everything is fine.
END;
Of course it won't work if the table doesn't exist. Your second select would get a "No data found" exception, and you're not doing any exception handling. At least you should move the second select inside the first IF block. Best to add exception handling.
here is an easy way to solve this problem:
BEGIN
EXECUTE IMMEDIATE 'DROP TABLE [sssss]';
EXCEPTION WHEN OTHERS THEN NULL;
END;
CREATE OR REPLACE PROCEDURE ResetVersionNumberValue IS
sql_stmt VARCHAR2(2000);
BEGIN
FOR sql_stmt IN (select 'update '|| table_name ||
' set version = 0'
from user_tables
where table_name like 'MY_%')
LOOP
EXECUTE IMMEDIATE sql_stmt;
END LOOP;
COMMIT;
END;
Why the about procedure is not compiling? Its giving error saying
Error(8,26): PLS-00382: expression is of wrong type
How to resolve this?
Two things:
You need to remember that when iterating a cursor it returns a ROW, not a VALUE, and
The SELECT in the cursor needs to give a name to the value in the row being generated by the cursor.
Try:
CREATE OR REPLACE PROCEDURE ResetVersionNumberValue IS
BEGIN
FOR aRow IN (select 'update '|| table_name ||
' set version = 0' AS SQL_STMT
from user_tables
where table_name like 'MY_%')
LOOP
EXECUTE IMMEDIATE aRow.SQL_STMT;
END LOOP;
COMMIT;
END;
Share and enjoy.
CREATE OR REPLACE PROCEDURE ResetVersionNumberValue IS
BEGIN
FOR sql_stmt IN (
select 'update '|| table_name || ' set version = 0' as x
from user_tables
where table_name like 'MY_%')
LOOP
EXECUTE IMMEDIATE sql_stmt.x;
END LOOP;
COMMIT;
END;
I need a help on this.
I am trying to create a pl/sql anonymous block and when I run that it shows its completed but it don't run the code. It should give me an error saying name is already used by an existing object. Can someone help me on this.
I am actually creating procedures but just trying this code as a sample.
DECLARE
V_REF_TBL VARCHAR2(100);
V_SQL LONG;
begin
V_REF_TBL :='My_TABLE';
v_SQL :='truncate table '||V_REF_TBL ;
EXECUTE IMMEDIATE V_SQL;
EXECUTE IMMEDIATE 'CREATE TABLE '|| V_REF_TBL ||' parallel 9 nologging pctfree 0 as
select * from dual';
End;
Possibly you're looking for this:
<<my_block>>
Declare
table_name varchar2(30);
counter number;
Begin
table_name := 'my_table';
select count(*)
into counter
from user_tables
where table_name = Upper(Trim(my_block.table_name)) and
dropped = 'NO';
if counter = 0
then
execute immediate 'create table '||table_name||' as ... etc';
else
execute immediate 'truncate table '||table_name;
execute immediate 'insert into '||table_name' select ... etc';
end if;
end my_block;
I need to drop a table and make a new one. If I drop the table and the table doesn't exist, I get an error
How can I check if the table exists?
I'm working on Oracle 11g
Thanks in advance.
You could do something like this:
DECLARE v_exist PLS_INTEGER;
BEGIN
SELECT COUNT(*) INTO v_exist
FROM user_tables
WHERE table_name = 'YOURTABLEHERE';
IF v_exist = 1 THEN
EXECUTE IMMEDIATE 'DROP TABLE YOURTABLEHERE';
END IF;
DECLARE
eTABLE_OR_VIEW_DOES_NOT_EXIST EXCEPTION;
PRAGMA EXCEPTION_INIT(eTABLE_OR_VIEW_DOES_NOT_EXIST, -942);
BEGIN
EXECUTE IMMEDIATE 'DROP TABLE SCHEMA.WHATEVER';
EXCEPTION
WHEN eTABLE_OR_VIEW_DOES_NOT_EXIST THEN
NULL;
END;
Share and enjoy.
something like
select count(*) from user_tables
where table_name= :table name
or
select count(*) from dba_tables
where owner = :table owner
and table_name = :table name
or a heavy-handed alternative:
begin execute immediate 'drop table table_name';
exception when others then null;
end;
I have been using the following procedure to take care of this:
create or replace procedure drop_table_if_exists ( p_table_name varchar2 )
is
it_exist number;
begin
select count(*)
into it_exists
from user_tables
where table_name = p_table_name
;
if it_exists >= 1 then
execute immediate 'drop table '||p_table_name;
end if;
end;
/
exec drop_table_if_exists ( 'TABLE_TO_DROP' );