dynamic sql with quotes and execute immediate - oracle

I get tripped up using dynamic sql and quotes. When I dbms_output the sql_stmt, it outputs valid/working code. How should the sql_stmt := line be written so that I can dynamically execute it? I have tried ":1 using" bind variable syntax as well with no luck.
The point of this code is to gather stats for a subset of tables.
set serveroutput on
--create this test table for working example.
--create table test3 as select table_name from user_tables where rownum <= 5;
declare
sql_stmt varchar2(500);
begin
for rec in (select table_name from test3)
loop
sql_stmt := 'exec dbms_stats.gather_table_stats (''SCOTT'',''' || rec.table_name || ''')';
dbms_output.put_line(sql_stmt);
execute immediate sql_stmt; -- <---Error is here---
end loop;
end;
The errors I get from the execute immediate sql_stmt; line is:
ORA-00900: invalid SQL statement
ORA-06512: at line 8

EXEC is an SQL*Plus command. You may want to wrap the call to DBMS_STATS.GATHER_TABLE_STATS in an anonymous block instead if you insist on using dynamic SQL.
However, you should be able to call the procedure directly, like so:
declare
sql_stmt varchar2(500);
begin
for rec in (select table_name from test3)
loop
dbms_stats.gather_table_stats ('SCOTT',rec.table_name);
end loop;
end;

Use
sql_stmt := 'BEGIN dbms_stats.gather_table_stats (''SCOTT'','''
|| rec.table_name || '''); END;';
instead.

Related

Drop Index , then Insert Statement after that Create back Index, does not work in Procedure

create or replace PROCEDURE INSSEL_TBL_TEST AS
BEGIN
DECLARE
TBL varchar2(50):= 'ESSCSHSTMTBPTEST2';
tblNm varchar2(50);
CURSOR tableIndexList IS
(select ES_INDEX_NM,ES_TBL_NM,ES_CRT_INDEX_STMT,ES_DROP_INDEX_STMT FROM ESSP.ESSINDEXCONF WHERE ES_TBL_NM = TBL);
BEGIN
FOR drpInd in tableIndexList LOOP
EXECUTE IMMEDIATE 'drpInd.ES_DROP_INDEX_STMT';
COMMIT;
END LOOP;
execute immediate ('insert into ESSPREP.' ||UPPER(TBL)|| ' select * from ESSP.' ||UPPER(TBL)|| '#ESSPREPLINKESSP');
FOR drpInd in tableIndexList Loop
execute immediate 'drpInd.ES_CRT_INDEX_STMT';
COMMIT;
END LOOP;
END;
END;
above is my procedure to drop index before insert statement, after that create back the index.But it not work,anyone can help ?
Line
EXECUTE IMMEDIATE 'drpInd.ES_DROP_INDEX_STMT';
is wrong. You're trying to use value from cursor but as a fact you're using string literal. To fix this error just remove quotes:
EXECUTE IMMEDIATE drpInd.ES_DROP_INDEX_STMT;
Also, as #XING said, commit is superfluous here.
Your syntax is not correct. See below:
create or replace PROCEDURE INSSEL_TBL_TEST
AS
TBL varchar2(50):= 'ESSCSHSTMTBPTEST2';
tblNm varchar2(50);
CURSOR tableIndexList IS
(select ES_INDEX_NM,ES_TBL_NM,ES_CRT_INDEX_STMT,ES_DROP_INDEX_STMT FROM ESSP.ESSINDEXCONF WHERE ES_TBL_NM = TBL);
BEGIN
FOR drpInd in tableIndexList LOOP
EXECUTE IMMEDIATE drpInd.ES_DROP_INDEX_STMT;
--COMMIT;-- DROP is a DDL hence no need for COMMIT
END LOOP;
execute immediate 'insert into ESSPREP.' ||UPPER(TBL)|| ' select * from ESSP.' ||UPPER(TBL)|| '#ESSPREPLINKESSP';
FOR drpInd in tableIndexList Loop
execute immediate drpInd.ES_CRT_INDEX_STMT;
END LOOP;
END;

How can I make an entire PL/SQL code block dynamic with bind variables?

Background
I'm trying to make a re-usable PL/SQL procedure to move data from one
database to another.
For this purpose, I'm using dynamic SQL.
The procedure executes perfectly if I use a REPLACE with placeholders.
However, for security reasons, I want to use bind variables.
Question
How can I make an entire PL/SQL code block dynamic (with bind
variables)? If I use a REPLACE instead of the bind variables, it works
fine.
How to replicate
To replicate this in your database, create the following procedure as it is:
create or replace procedure move_data(i_schema_name in varchar2, i_table_name in varchar2, i_destination in varchar2) as
l_sql varchar2(32767);
l_cursor_limit pls_integer := 500;
l_values_list varchar2(32767);
begin
select listagg('l_to_be_moved(i).' || column_name, ', ') within group (order by column_id)
into l_values_list
from all_tab_cols
where owner = i_schema_name and
table_name = i_table_name and
virtual_column = 'NO';
l_sql := q'[
declare
l_cur_limit pls_integer := :l_cursor_limit;
cursor c_get_to_be_moved is
select :i_table_name.*, :i_table_name.rowid
from :i_table_name;
type tab_to_be_moved is table of c_get_to_be_moved%rowtype;
l_to_be_moved tab_to_be_moved;
begin
open c_get_to_be_moved;
loop
fetch c_get_to_be_moved
bulk collect into l_to_be_moved limit l_cur_limit;
exit when l_to_be_moved.count = 0;
for i in 1.. l_to_be_moved.count loop
begin
insert into :i_table_name#:i_destination values (:l_values_list);
exception
when others then
dbms_output.put_line(sqlerrm);
l_to_be_moved.delete(i);
end;
end loop;
forall i in 1.. l_to_be_moved.count
delete
from :i_table_name
where rowid = l_to_be_moved(i).rowid;
for i in 1..l_to_be_moved.count loop
if (sql%bulk_rowcount(i) = 0) then
raise_application_error(-20001, 'Could not find ROWID to delete. Rolling back...');
end if;
end loop;
commit;
end loop;
close c_get_to_be_moved;
exception
when others then
rollback;
dbms_output.put_line(sqlerrm);
end;]';
execute immediate l_sql using l_cursor_limit, i_table_name, i_destination, l_values_list;
exception
when others then
rollback;
dbms_output.put_line(sqlerrm);
end;
/
And then you can execute the procedure with the following:
begin
move_data('MySchemaName', 'MyTableName', 'MyDatabaseLinkName');
end;
/
Due to many reasons(inability to generate an appropriate execution plan, security checking, etc.) Oracle does not allow identifiers binding (table names, schema names, column names and so on). So if it's really necessary, the only way is to hard code those identifiers after some sort of validation (to prevent SQL injection).
If I understand well, you could try a trick, by using a dynamic SQL inside a dynamic SQL.
setup:
create table tab100 as select level l from dual connect by level <= 100;
create table tab200 as select level l from dual connect by level <= 200;
create table tabDest as select * from tab100 where 1 = 2;
This will not work:
create or replace procedure testBind (pTableName in varchar2) is
vSQL varchar2(32000);
begin
vSQL := 'insert into tabDest select * from :tableName';
execute immediate vSQL using pTableName;
end;
But this will do the trick:
create or replace procedure testBind2 (pTableName in varchar2) is
vSQL varchar2(32000);
begin
vSQL := q'[declare
vTab varchar2(30) := :tableName;
vSQL2 varchar2(32000) := 'insert into tabDest select * from ' || vTab;
begin
execute immediate vSQL2;
end;
]';
execute immediate vSQL using pTableName;
end;
I think you can do it simpler.
create or replace procedure move_data(i_schema_name in varchar2, i_table_name in varchar2, i_destination in varchar2) as
l_sql varchar2(32767);
begin
select listagg('l_to_be_moved(i).' || column_name, ', ') within group (order by column_id)
into l_values_list
from all_tab_cols
where owner = i_schema_name and
table_name = i_table_name and
virtual_column = 'NO';
l_sql := 'insert into '||i_destination||'.'||i_table_name||' select * from '||i_schema_name||'.'||i_table_name;
execute immediate l_sql;
end;
If you are concerned about SQL-Injection, have a look at package DBMS_ASSERT. This PL/SQL package provides function to validate properties of input values.

Why the Oracle procedure not compiling?

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;

anonymous block in 11g

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;

using pl/sql to update sequences

We have a sql script to update a set of sequences after seed data populated our tables. The code below would not work:
declare
cursor c1 is
select
'select nvl(max(id),0) from '||uc.table_name sql_text,
uc.table_name||'_SEQ' sequence_name
from
user_constraints uc,
user_cons_columns ucc
where uc.constraint_type='P'
and ucc.constraint_name = uc.constraint_name
and ucc.column_name='ID'
and uc.owner='ME';
alter_sequence_text varchar2(1024);
TYPE generic_cursor_type IS REF CURSOR;
max_id number;
c2 generic_cursor_type;
begin
for r1 in c1 loop
open c2 for r1.sql_text;
fetch c2 into max_id;
close c2;
if( max_id != 0 ) then
dbms_output.put_line( 'seq name = '||r1.sequence_name );
execute immediate 'alter sequence '||r1.sequence_name||' increment by '||to_char(max_id);
dbms_output.put_line( 'max_id = '||to_char(max_id) );
execute immediate 'select '||r1.sequence_name||'.nextval from dual';
dbms_output.put_line( 'sequence value = '||to_char(next_id) );
execute immediate 'alter sequence '||r1.sequence_name||' increment by 1';
dbms_output.put_line( 'sequence: '||r1.sequence_name||' is at '||to_char(max_id+1) );
end if;
end loop;
end;
After searching I found a reference that stated I needed to change the line:
execute immediate 'select '||r1.sequence_name||'.nextval from dual'
and add 'into next_id;' (of course declaring next_id appropriately) so the result would be:
execute immediate 'select '||r1.sequence_name||'.nextval from dual into next_id;
I've only dealt lightly with pl/sql and sql in general and am interested to know why this change was necessary to make the script work correctly.
Thanks.
When you are using select inside PL/SQL block you have to place data returned by that select statement somewhere. So you have to declare a variable of appropriate data type and use select into clause to put data select returns into that variable even if select statement is executed by execute immediate statement.
Examples
declare
x number;
begin
select count(*)
into x
from all_objects;
end;
declare
x number;
begin
execute immediate 'select count(*)from all_objects' into x;
end;
So your execute immediate statement would be
execute immediate 'select '||sequence_name||'.nextval from dual' into newseqval;
If you are using Oracle 11g onward you can assign sequence's value directly to a variable, there is no need of using select into clause.
declare
x number;
begin
x := Sequence_Name.nextval;
end;
select seq_name.nextval from dual implies the implicit cursor creation and the results of the cursor should be fetched somewhere so you need fetch it into any externally declared bind variable.

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