I am trying to write a sql to select all data from a list of views for a particular view.
I'm getting all the user view this way:
select view_name from user_views
Say the output is:
emp_v
dept_v
countries_v
jobs_v
Is it possible for me to pass one of these views as parameter in the original sql(which is pulling all the views) so i can get all the data in this view?
Thanks
This might be what you are looking for. This will loop those views and select everything in them. NOTE: This can cause a lot of DBMS_OUTPUT. I suggest hardcoding the cursor for a specific view first to make sure it is what you are looking for.
(1) Create this procedure...
CREATE OR REPLACE procedure print_view(p_query in varchar2) is
l_theCursor integer default dbms_sql.open_cursor;
l_columnValue varchar2(4000);
l_status integer;
l_descTbl dbms_sql.desc_tab;
l_rowCnt number := 0;
l_colCnt number;
begin
dbms_sql.parse(l_theCursor, p_query, dbms_sql.native);
dbms_sql.describe_columns(l_theCursor, l_colCnt, l_descTbl);
dbms_output.put_line(l_colCnt);
for i in 1 .. l_colCnt loop
dbms_sql.define_column(l_theCursor, i, l_columnValue, 4000);
end loop;
l_status := dbms_sql.execute(l_theCursor);
while(dbms_sql.fetch_rows(l_theCursor) > 0) loop
l_rowCnt := l_rowCnt +1;
dbms_output.put_line('========== ROW '||l_rowCnt||' ==========');
for i in 1 .. l_colCnt loop
dbms_sql.column_value(l_theCursor, i, l_columnValue);
dbms_output.put_line(rpad(l_descTbl(i).col_name, 30)||': '||substr(l_columnValue, 1, 200));
end loop;
end loop;
end print_view;
/
(2) Then run this...
declare
/*
NOTE: Edit the where clause. You should try this with just a single view first to make sure this is what you want.
*/
cursor cursor1 is
select view_name from user_views
where view_name in ('emp_v','dept_v','countries_v','jobs_v');
begin
for c1 in cursor1 loop
print_view('select * from '|| c1.view_name); /* Pass the view as a parameter like requested. */
end loop;
end;
/
Related
I'd like to create an in-memory array variable that can be used in my PL/SQL code. I can't find any collections in Oracle PL/SQL that uses pure memory, they all seem to be associated with tables. I'm looking to do something like this in my PL/SQL (C# syntax):
string[] arrayvalues = new string[3] {"Matt", "Joanne", "Robert"};
Edit:
Oracle: 9i
You can use VARRAY for a fixed-size array:
declare
type array_t is varray(3) of varchar2(10);
array array_t := array_t('Matt', 'Joanne', 'Robert');
begin
for i in 1..array.count loop
dbms_output.put_line(array(i));
end loop;
end;
Or TABLE for an unbounded array:
...
type array_t is table of varchar2(10);
...
The word "table" here has nothing to do with database tables, confusingly. Both methods create in-memory arrays.
With either of these you need to both initialise and extend the collection before adding elements:
declare
type array_t is varray(3) of varchar2(10);
array array_t := array_t(); -- Initialise it
begin
for i in 1..3 loop
array.extend(); -- Extend it
array(i) := 'x';
end loop;
end;
The first index is 1 not 0.
You could just declare a DBMS_SQL.VARCHAR2_TABLE to hold an in-memory variable length array indexed by a BINARY_INTEGER:
DECLARE
name_array dbms_sql.varchar2_table;
BEGIN
name_array(1) := 'Tim';
name_array(2) := 'Daisy';
name_array(3) := 'Mike';
name_array(4) := 'Marsha';
--
FOR i IN name_array.FIRST .. name_array.LAST
LOOP
-- Do something
END LOOP;
END;
You could use an associative array (used to be called PL/SQL tables) as they are an in-memory array.
DECLARE
TYPE employee_arraytype IS TABLE OF employee%ROWTYPE
INDEX BY PLS_INTEGER;
employee_array employee_arraytype;
BEGIN
SELECT *
BULK COLLECT INTO employee_array
FROM employee
WHERE department = 10;
--
FOR i IN employee_array.FIRST .. employee_array.LAST
LOOP
-- Do something
END LOOP;
END;
The associative array can hold any make up of record types.
Hope it helps,
Ollie.
You can also use an oracle defined collection
DECLARE
arrayvalues sys.odcivarchar2list;
BEGIN
arrayvalues := sys.odcivarchar2list('Matt','Joanne','Robert');
FOR x IN ( SELECT m.column_value m_value
FROM table(arrayvalues) m )
LOOP
dbms_output.put_line (x.m_value||' is a good pal');
END LOOP;
END;
I would use in-memory array. But with the .COUNT improvement suggested by uziberia:
DECLARE
TYPE t_people IS TABLE OF varchar2(10) INDEX BY PLS_INTEGER;
arrayvalues t_people;
BEGIN
SELECT *
BULK COLLECT INTO arrayvalues
FROM (select 'Matt' m_value from dual union all
select 'Joanne' from dual union all
select 'Robert' from dual
)
;
--
FOR i IN 1 .. arrayvalues.COUNT
LOOP
dbms_output.put_line(arrayvalues(i)||' is my friend');
END LOOP;
END;
Another solution would be to use a Hashmap like #Jchomel did here.
NB:
With Oracle 12c you can even query arrays directly now!
Another solution is to use an Oracle Collection as a Hashmap:
declare
-- create a type for your "Array" - it can be of any kind, record might be useful
type hash_map is table of varchar2(1000) index by varchar2(30);
my_hmap hash_map ;
-- i will be your iterator: it must be of the index's type
i varchar2(30);
begin
my_hmap('a') := 'apple';
my_hmap('b') := 'box';
my_hmap('c') := 'crow';
-- then how you use it:
dbms_output.put_line (my_hmap('c')) ;
-- or to loop on every element - it's a "collection"
i := my_hmap.FIRST;
while (i is not null) loop
dbms_output.put_line(my_hmap(i));
i := my_hmap.NEXT(i);
end loop;
end;
Sample programs as follows and provided on link also https://oracle-concepts-learning.blogspot.com/
plsql table or associated array.
DECLARE
TYPE salary IS TABLE OF NUMBER INDEX BY VARCHAR2(20);
salary_list salary;
name VARCHAR2(20);
BEGIN
-- adding elements to the table
salary_list('Rajnish') := 62000; salary_list('Minakshi') := 75000;
salary_list('Martin') := 100000; salary_list('James') := 78000;
-- printing the table name := salary_list.FIRST; WHILE name IS NOT null
LOOP
dbms_output.put_line ('Salary of ' || name || ' is ' ||
TO_CHAR(salary_list(name)));
name := salary_list.NEXT(name);
END LOOP;
END;
/
Using varray is about the quickest way to duplicate the C# code that I have found without using a table.
Declare your public array type to be use in script
type t_array is varray(10) of varchar2(60);
This is the function you need to call - simply finds the values in the string passed in using a comma delimiter
function ConvertToArray(p_list IN VARCHAR2)
RETURN t_array
AS
myEmailArray t_array := t_array(); --init empty array
l_string varchar2(1000) := p_list || ','; - (list coming into function adding final comma)
l_comma_idx integer;
l_index integer := 1;
l_arr_idx integer := 1;
l_email varchar2(60);
BEGIN
LOOP
l_comma_idx := INSTR(l_string, ',', l_index);
EXIT WHEN l_comma_idx = 0;
l_email:= SUBSTR(l_string, l_index, l_comma_idx - l_index);
dbms_output.put_line(l_arr_idx || ' - ' || l_email);
myEmailArray.extend;
myEmailArray(l_arr_idx) := l_email;
l_index := l_comma_idx + 1;
l_arr_idx := l_arr_idx + 1;
END LOOP;
for i in 1..myEmailArray.count loop
dbms_output.put_line(myEmailArray(i));
end loop;
dbms_output.put_line('return count ' || myEmailArray.count);
RETURN myEmailArray;
--exception
--when others then
--do something
end ConvertToArray;
Finally Declare a local variable, call the function and loop through what is returned
l_array t_array;
l_Array := ConvertToArray('email1#gmail.com,email2#gmail.com,email3#gmail.com');
for idx in 1 .. l_array.count
loop
l_EmailTo := Trim(replace(l_arrayXX(idx),'"',''));
if nvl(l_EmailTo,'#') = '#' then
dbms_output.put_line('Empty: l_EmailTo:' || to_char(idx) || l_EmailTo);
else
dbms_output.put_line
( 'Email ' || to_char(idx) ||
' of array contains: ' ||
l_EmailTo
);
end if;
end loop;
I have a general SYS_REFCURSOR that I want to check if it is empty or not.
The code is like this:
declare
v_cursor SYS_REFCURSOR;
begin
OPEN v_cursor FOR <any select statement>.
check if v_cursor is empty.
end;
Can someone tell me how to check if the weak cursor is empty, please?
I have to mention that the base SELECT statement can be anything from any table.
The column numbers or type it is known only at runtime.
Thank you,
You can't see if a ref cursor contains data without fetching, and consuming at least one row from it.
If you really need to determine this at the point the cursor is opened, without knowing the structure at that point, you could execute a modified query that just counts the rows returned by your real query - possibly limited to a single row if that helps performance - either as a simple execute immediate ... into ... or with a separate open/fetch/close for consistency; something like:
declare
v_cursor SYS_REFCURSOR;
v_query VARCHAR2(4000);
v_count PLS_INTEGER;
begin
v_query := <any select statement>;
-- see if the query finds any data
OPEN v_cursor FOR 'select count(*) from (' || v_query || ')'; -- could limit rows
FETCH v_cursor INTO v_count;
CLOSE v_cursor;
if v_count = 0 then
dbms_output.put_line('No data');
return;
end if;
dbms_output.put_line('Found data, opening cursor for real');
OPEN v_cursor FOR v_query;
-- loop over results, return to caller, etc.
end;
/
db<>fiddle
Try to fetch a row and then use v_cursor%NOTFOUND to determine of the cursor is empty:
DECLARE
v_cursor SYS_REFCURSOR;
v_value DUAL.DUMMY%TYPE;
BEGIN
OPEN v_cursor FOR SELECT DUMMY FROM DUAL WHERE 1 = 0;
FETCH v_cursor INTO v_value;
IF v_cursor%NOTFOUND THEN
DBMS_OUTPUT.PUT_LINE('Cursor empty');
ELSE
DBMS_OUTPUT.PUT_LINE('Cursor not empty');
END IF;
END;
/
or
DECLARE
CURSOR v_cursor IS
SELECT DUMMY FROM DUAL WHERE 1 = 0;
v_row v_cursor%ROWTYPE;
BEGIN
OPEN v_cursor;
FETCH v_cursor INTO v_row;
IF v_cursor%NOTFOUND THEN
DBMS_OUTPUT.PUT_LINE('Cursor empty');
ELSE
DBMS_OUTPUT.PUT_LINE('Cursor not empty');
END IF;
END;
/
Both output:
Cursor empty
db<>fiddle here
I'm completely new to SQL, and am currently taking a class in it right now for databases. I am told to create a trigger signature that would capture information when anyone creates or drops an object.
I have no idea where to start, anything will help! I'm looking into trigger signatures right now but how do I know when someone creates/drops an object? So far I have been thinking it might be something like:
BEFORE CREATE OR DROP
Thanks!
In your sys or system schema, you can try trigger below;
create or replace trigger trg_adm_ddl before ddl on database
declare
begin
pr_ddl_oper;
end;
*where* pr_ddl_oper is ;
create or replace procedure pr_ddl_oper as
v_oty varchar2(75) := ora_dict_obj_type;
v_don varchar2(75) := ora_dict_obj_name;
v_evt varchar2(75) := ora_sysevent;
v_olu varchar2(75) := nvl(ora_login_user,'Unknown Schema');
v_sql ora_name_list_t;
v_stm clob;
v_sct owa.vc_arr;
n pls_integer;
n_max pls_integer := 10000;
begin
v_sct(1) := 'SESSIONID';
v_sct(2) := 'IP_ADDRESS';
v_sct(3) := 'TERMINAL';
v_sct(4) := 'OS_USER';
v_sct(5) := 'AUTHENTICATION_TYPE';
v_sct(6) := 'CLIENT_INFO';
v_sct(7) := 'MODULE';
for i in 1..7
loop
v_sct(i) := sys_context('USERENV',v_sct(i));
end loop;
select decode(v_sct(1),0,null,v_sct(1)),decode(upper(v_sct(3)),'UNKNOWN',null,v_sct(3)) into v_sct(1),v_sct(3) from dual;
n := ora_sql_txt( v_sql );
if n > n_max then
n := n_max;
end if;
for i in 1..n
loop
v_stm := v_stm || v_sql(i);
end loop;
insert into usr_audit.log_ddl(col_datetime,col_user,col_evnt,col_statement,col_sessionid,col_ip,col_terminal,col_osuser,col_auttype,col_objecttype,col_objectname,col_clientinfo,col_moduleinfo)
values(sysdate,v_olu,v_evt,v_stm,v_sct(1),v_sct(2),v_sct(3),v_sct(4),v_sct(5),v_oty,v_don,v_sct(6),v_sct(7));
end;
after constructing this mechanism, you may enquiry the results with a sql like this one;
select * from usr_audit.log_ddl t
where lower(t.stmt) like '%alter%table%modify%'
order by t.col_datetime desc
or you may use the below way easily (if your db is at least 11g);
$ alter system set enable_ddl_logging=true;
your DDL log file data is written in XML format to a file in your OS.
Dynamic SQL is not my friend, basically the idea is that I can use the procedure with the "p_in_table" paramter to get the number of rows contained in the table.
CREATE OR REPLACE PROCEDURE how_many_rows(p_in_table VARCHAR2)
IS
TYPE cur_cur IS REF CURSOR;
v_cur_cur cur_cur;
v_rowcount NUMBER(28);
v_cur_txt VARCHAR2(299);
BEGIN
v_cur_txt := 'SELECT * FROM ' || p_in_table;
OPEN v_cur_cur FOR v_cur_txt;
LOOP
v_rowcount := v_cur_cur%ROWCOUNT;
EXIT WHEN v_cur_cur%NOTFOUND;
END LOOP;
CLOSE v_cur_cur;
dbms_output.put_line(v_rowcount);
END;
Would preciate it if someone would tell me what am I doing wrong?
The problem is that you not iterating through cursor - no fetch statement or something like that, so, basically, you have an infinite loop. To avoid this you need to do something like this:
CREATE OR REPLACE PROCEDURE how_many_rows
(p_in_table VARCHAR2) IS
TYPE cur_cur IS REF CURSOR;
v_cur_cur cur_cur;
v_rowcount NUMBER(28);
v_cur_txt VARCHAR2(299);
v_row SOME_TABLE%ROWTYPE; --add row variable
BEGIN
v_cur_txt := 'SELECT * FROM '|| p_in_table;
OPEN v_cur_cur FOR v_cur_txt;
LOOP
v_rowcount := v_cur_cur%ROWCOUNT;
FETCH v_cur_cur INTO v_row; --fetch a row in it
EXIT WHEN v_cur_cur%NOTFOUND;
END LOOP;
CLOSE v_cur_cur;
DBMS_OUTPUT.PUT_LINE(v_rowcount);
END;
But, as you can see, to do this you need to know, what table you're quering, so this is not general solution. Maybe there is a workaround for this, but i suggest, you use more simple and efficient approach, for example with EXECUTE IMMEDIATE:
CREATE OR REPLACE PROCEDURE HOW_MANY_ROWS(p_in_table VARCHAR2)
IS
v_tmp NUMBER;
BEGIN
EXECUTE IMMEDIATE 'SELECT COUNT(1) FROM ' || p_in_table INTO v_tmp;
DBMS_OUTPUT.PUT_LINE(v_tmp);
END;
Ok, I gave a thought on how to achieve this using your way, and here is what i've ended up with - just fetch ROWNUM from your table, every table has it and you know it's type - NUMBER. So this procedure will work in general case:
CREATE OR REPLACE PROCEDURE how_many_rows
(p_in_table VARCHAR2) IS
TYPE cur_cur IS REF CURSOR;
v_cur_cur cur_cur;
v_rowcount NUMBER(28);
v_cur_txt VARCHAR2(299);
v_row NUMBER; --add rownum variable
BEGIN
v_cur_txt := 'SELECT ROWNUM FROM '|| p_in_table; --select only rownum from target table
OPEN v_cur_cur FOR v_cur_txt;
LOOP
v_rowcount := v_cur_cur%ROWCOUNT;
FETCH v_cur_cur INTO v_row; --fetch rownum in it
EXIT WHEN v_cur_cur%NOTFOUND;
END LOOP;
CLOSE v_cur_cur;
DBMS_OUTPUT.PUT_LINE(v_rowcount);
END;
I'm using Pl/SQL with Oracle Database 11g.
I'm writing a function that takes in a select statement as a parameter (varchar2). The function uses a for loop to go over the rows and apply formatting to specific columns, and output the whole thing. Basically, I need some way to get the column names so that I can display them at the top. I know there are various ways to do this for tables, but since this query is passed in, all columns may not have been selected, aliases may have been used, etc.
Is there a way I can select out the column names from this query?
Ideally something like:
select column_names from (subquery)
I believe you can use DESCRIBE_COLUMNS to do this. Just pass in the cursor and the other required parameters.
http://docs.oracle.com/cd/B19306_01/appdev.102/b14258/d_sql.htm#i1026120
declare
v_sql varchar2(32767) := 'select 1 column1, 2 column2 from dual';
v_cursor_id integer;
v_col_cnt integer;
v_columns dbms_sql.desc_tab;
begin
v_cursor_id := dbms_sql.open_cursor;
dbms_sql.parse(v_cursor_id, v_sql, dbms_sql.native);
dbms_sql.describe_columns(v_cursor_id, v_col_cnt, v_columns);
for i in 1 .. v_columns.count loop
dbms_output.put_line(v_columns(i).col_name);
end loop;
dbms_sql.close_cursor(v_cursor_id);
exception when others then
dbms_sql.close_cursor(v_cursor_id);
raise;
end;
/
Output:
COLUMN1
COLUMN2
Based on dseibert's answer, I created function for usage:
create type cols_name
as table of varchar2(32767)
/
CREATE OR REPLACE FUNCTION GET_COLUMNS_NAME(p_selectQuery IN VARCHAR2) RETURN cols_name PIPELINED IS
v_cursor_id integer;
v_col_cnt integer;
v_columns dbms_sql.desc_tab;
begin
v_cursor_id := dbms_sql.open_cursor;
dbms_sql.parse(v_cursor_id, p_selectQuery, dbms_sql.native);
dbms_sql.describe_columns(v_cursor_id, v_col_cnt, v_columns);
for i in 1 .. v_columns.count loop
pipe row(v_columns(i).col_name);
end loop;
dbms_sql.close_cursor(v_cursor_id);
return;
exception when others then
dbms_sql.close_cursor(v_cursor_id);
raise;
end;
/
Using it:
select * from TABLE(get_columns_name('select 1 column1, 2 column2 from dual'));
Results:
**COLUMN_VALUE**
COLUMN1
COLUMN2