I am using with clause in my function where passing table name as parameter. So want use this table name in the query but giving table doesnot exits.Sample query
with EMP_A as(
select EMPNO, SAL
from EMP
where DEPTNO in (select DEPTNO from P_TABLE_NAME))
select * from EMP;
In your below posted query:
With emp_a as (
select empno,sal
from emp
where deptno in(select deptno from p_table_name)
)
select * from emp;
Firstly, you cannot have dynamic table name in SQL. Object names must be static. You need to (ab)use EXECUTE IMMEDIATE in PL/SQL to make it a dynamic SQL.
Secondly, your CTE and tablename are different. Your CTE is emp_a, while the table you are referring to is emp.
Thirdly, you use the WITH clause, i.e. subquery factoring when you have to use the subquery multiple times. Therefore, the CTE would act as a temporary taboe to hold the subquery resultset.
See the documentation to learn more about EXECUTE IMMEDIATE.
http://docs.oracle.com/cd/B19306_01/appdev.102/b14261/executeimmediate_statement.htm
UPDATE An example
You could use a string variable to assign the dynamic query.
DECLARE
p_table_name VARCHAR2(30);
l_sql VARCHAR2(32767);
l_value. NUMBER;
BEGIN
p_table_name := 'DEPARTMENT';
l_sql := 'WITH clause...' || p_table_name || ' with clause contunied';
EXECUTE IMMEDIATE l_sql INTO l_value;
Related
I have the following block of PL-SQL code in Oracle:
DECLARE TAB VARCHAR(100);
COL VARCHAR(100);
CURSOR C_COLS IS
select DISTINCT table_name, column_name
from all_tab_columns
where OWNER = 'MyDB' AND DATA_TYPE LIKE '%VARCHAR%';
BEGIN
OPEN C_COLS;
LOOP
FETCH C_COLS INTO TAB, COL;
EXIT WHEN C_COLS%notfound;
INSERT INTO TargetTable (TABLE_NAME, COLUMN_NAME, COLUMN_VALUE)
SELECT DISTINCT TAB,
COL,
(SELECT COL FROM TAB)
FROM TAB
WHERE REGEXP_LIKE(COL, '([ABCDEFGHIJKLMNOPQRSTUVWXYZ])\d\d\d\d\d\d([ABCDEFGHIJKLMNOPQRSTUVWXYZ])', 'ix');
END LOOP;
CLOSE C_COLS;
END;
The idea is to determine which tables in my rather large database contain a certain pattern of data and to find them.
So I want to return three columns: TableName, ColumnName, Value of ColumnName.
The above runs but returns no data and I can't understand why. The query in the cursor returns results, and if I hard code the table values into a simple select statement containing my Regex, I get results. I just want one result set that contains the thousands of results I expect.
Could it be the (SELECT COL FROM TAB) I'm using to dynamically find the column_value? I wasn't sure if I could express it this way.
If you want to select columns dynamically you may wish to try dynamic SQL.
DECLARE
w_sql VARCHAR2(32767);
BEGIN
DBMS_OUTPUT.enable(32767);
FOR s_cols IN (
select DISTINCT
table_name
, column_name
from all_tab_columns
where owner = 'MyDB'
AND data_type LIKE '%VARCHAR%'
)
LOOP
w_sql := q'!
INSERT
INTO TargetTable (TABLE_NAME, COLUMN_NAME, COLUMN_VALUE)
SELECT DISTINCT
':TAB'
, ':COL'
, :COL
FROM :TAB
WHERE REGEXP_LIKE(:COL, '([ABCDEFGHIJKLMNOPQRSTUVWXYZ])\d\d\d\d\d\d([ABCDEFGHIJKLMNOPQRSTUVWXYZ])', 'ix')
!';
w_sql := REPLACE(w_sql, ':TAB', s_cols.table_name);
w_sql := REPLACE(w_sql, ':COL', s_cols.column_name);
EXECUTE IMMEDIATE w_sql;
END LOOP;
COMMIT;
EXCEPTION
WHEN OTHERS THEN
DBMS_OUTPUT.put_line('Error for SQL :'|| w_sql ||'; error is :'|| SQLERRM);
END;
I'm using Pl/SQL with Oracle Database 11g.
I want to get a list of columns with alias by a query string.
There is a way to get all the column names of a query, using dbms_sql.describe_columns2 but only I get alias.
For example:
DECLARE
l_cursor NUMBER := dbms_sql.open_cursor;
l_ignore NUMBER;
l_desc dbms_sql.desc_tab2;
l_cnt NUMBER;
BEGIN
dbms_sql.parse( l_cursor, 'select a.col1 column1, a.col2 column2 from table_test a', dbms_sql.native );
dbms_sql.describe_columns2( l_cursor, l_cnt, l_desc );
FOR i IN 1 .. l_cnt LOOP
dbms_output.put_line(l_desc(i).col_name);
END LOOP;
dbms_sql.close_cursor( l_cursor );
END;
/
Returns:
column1
column2
Is there any way to get the values a.col1, or a.col2 with alias in the query?
The column names used in a SQL statement can be retrieved using Rob van Wijk's custom view DBA_DEPENDENCY_COLUMNS.
Install the view as SYS and grant select on dba_dependency_columns to <your user>;.
The view only works on objects. Create a VIEW on the SELECT statement and then the dependencies will be available. For example:
create table table_test(col1 number, col2 number);
create or replace view test_view as
select a.col1 column1, a.col2 column2 from table_test a;
select referenced_column
from sys.dba_dependency_columns
where owner = user
and name = 'TEST_VIEW'
order by 1;
Results:
REFERENCED_COLUMN
-----------------
COL1
COL2
The above results get the "list of columns". But part of your answer also implies you may want to get the "column expressions". That would be a completely different task, but is possible. Parsing SQL can be ridiculously difficult so it might help to explain exactly what you want and why you want it.
Is there a way to count how many rows inserted into table by
Create table tbl1 as select * from tbl2;
statement which performed from PL\SQL function (execute immediate)?
When I'm using SQL%ROWCOUNT the result is 1.
Thanks.
You can try this. As mentioned in my comment you need to do it as followed. Remember that you need again to use Execute immediate else you get an issue that tab1 is undefined.
DECLARE
vsql VARCHAR2 (200);
cnt NUMBER;
BEGIN
vsql := 'create table tbl1 as select * from employee';
EXECUTE IMMEDIATE vsql;
vsql := 'select count(1) from tbl1';
EXECUTE IMMEDIATE vsql INTO cnt;
DBMS_OUTPUT.put_line (cnt);
END;
You can do one thing. You can first create an empty table tbl1 from tbl2. Then insert data using SELECT and then use- SQL%ROWCOUNT.
CREATE TABLE tbl1 AS SELECT * FROM tbl2 WHERE 1=2;
INSERT INTO tbl1 SELECT * FROM tbl2;
DBMS_OUTPUT.PUT_LINE ('No. of rows inserted in TBL2 from TBL1 = ' || SQL%ROWCOUNT);
I am new to Oracle and PL/SQL and am trying to do the following.
I am returning the column names from a table name that is stored in a variable
variable v_table varchar2(100)
begin
select 'mytable' into :v_table from dual;
end;
select column_name from all_tab_columns where table_name = :v_table
This returns a rowset
column_name
colname1
colname2
colname3
I would like to loop through the returned rowset and get some stats for each column.
select count distinct(colname1), min(colname1), max(colname1)
from :v_table
group by min(colname1), max(colname1)
However I cannot figure out how to loop through this rowset.
By using below you can display column names of a table and append your sql query as per your requirement...
declare
v_table varchar2(100):='TABLE_NAME';
TYPE NT_VAR1 IS TABLE OF VARCHAR2(30);
TYP_NT NT_VAR1;
begin
select column_name BULK COLLECT INTO TYP_NT from all_tab_columns where table_name =v_table
order by column_id;
FOR I IN 1..TYP_NT.COUNT
LOOP
DBMS_OUTPUT.PUT_LINE('COLUMN '||I||': '||TYP_NT(I));
END LOOP;
end;
Note: You should run select query dynamically means with the use of execute immediate why because you are passing table_name at run time.
Edit
After editing your query in for loop it will look like below.
declare
v_table varchar2(100):='TABLE_NAME';
TYPE NT_VAR1 IS TABLE OF VARCHAR2(30);
TYP_NT NT_VAR1;
var2 varchar2(2000);
var3 varchar2(2000);
begin
select column_name BULK COLLECT INTO TYP_NT from all_tab_columns where table_name =v_table
order by column_id;
FOR I IN 1..TYP_NT.COUNT
LOOP
DBMS_OUTPUT.PUT_LINE('COLUMN '||I||': '||TYP_NT(I));
EXECUTE IMMEDIATE 'SELECT to_char(min('||TYP_NT(I)||')),to_char(max('||TYP_NT(I)||')) from '||v_table into var2,var3;
dbms_output.put_line(var2||' '||var3);
END LOOP;
end;
Note: Find the max data length of a column present in your table and assign same data type to var2 and var3 variables.
I have a table with a few hundred partitions and I am generally interested on the latest 35.
Accordingly I am trying to create views which would access these dynamically. i.e. always use the latest in case ones are created.
The query:
select PARTITION_NAME,
PARTITION_POSITION,
NUM_ROWS,
AVG_ROW_LEN
from all_tab_partitions
where
table_name = 'MY_TABLE'
AND PARTITION_NAME <> 'P_LAST'
AND PARTITION_POSITION < (SELECT MAX(PARTITION_POSITION)
FROM all_tab_partitions) - 35
order by 2 DESC
;
Seems to return me the partition names I'm interested, however, I don't manage to use it's results to select the partitions. e.g.:
CREATE OR REPLACE VIEW MY_VIIEW AS
WITH t AS ( [Above query] )
SELECT * FROM
MY_TABLE PARTITION (SELECT /*+ FIRST_ROWS(1) */ PARTITION_NAME
from t);
(not the actual view, just an example)
So how do I do that? How do I create a view which will acess always the latest partition (execpt of "MAX")?
I am using Oracle 10g
thanks
You can do it using PL/SQL only
create or replace package my_table_ is
type t_records is table of my_table%rowtype;
function getpart(c_parts sys_refcursor) return t_records pipelined;
end;
create or replace package body my_table_ is
function getpart(c_parts sys_refcursor) return t_records pipelined is
v_partition all_tab_partitions.partition_name%type;
v_row my_table%rowtype;
c_mytab sys_refcursor;
begin
loop
fetch c_parts into v_partition;
exit when c_parts%notfound;
open c_mytab for 'select * from my_table partition ('||v_partition||')';
loop
fetch c_mytab into v_row;
exit when c_mytab%notfound;
pipe row (v_row);
end loop;
end loop;
end;
end;
Now you can
select * from table(my_table_.getpart(cursor(<QUERY_RETURNING_PARTITION_NAMES>)));
May be you can construct view's query using batch of union all statements with partition name in each statement, e.g.
create view p as
select * from my_table partition (part1)
union all
select * from my_table partition (part1)
...
union all
select * from my_table partition (part35)
Ok... I don't think your can use the Partition-Names, but you can use the Starting-Values of the Partitions to select the Data matching these Partitions...
So you View would look like this:
SELECT * FROM my_table WHERE date_col > get_part_limit( 'my_table', 35 ):
Where date_col is the column you use for partitioning - and get_part_limit is a stored function you write like this:
...
BEGIN
SELECT high_value FROM all_tab_partitions
INTO local_var
WHERE table_name = parameter_name
AND PARTITION_POSITION = MAX... - 35
EXECUTE IMMEDIATE 'SELECT '||local_var||' FROM DUAL' INTO local_return_value;
RETURN local_return_value;
END;
partitions are designed to be transparent for the data, so when you write a query, you simply don't know how your data is stored.
I see only one possibility to hit a particular partition: your WHERE clause should match values to the partitioned columns of latest (or latest 5) partition.
Next question is to build this WHERE clause on the fly. You already know that there is plenty of information in oracle dictionary. So you will read that and create a constructor to convert metadata conditions back into SQL.
irl we do exactly the same thing and use falco's solution like.
Here is my code:
create or replace function longToDate( myOwner varchar2,
mytable_name in varchar2,
mypartition_name in varchar2
) return date
as
cDate date;
cvar varchar2(1024);
rq varchar2(1024);
infiniteValue EXCEPTION;
PRAGMA EXCEPTION_INIT(infiniteValue, -00904);
begin
select high_value into cvar FROM dba_tab_partitions t where t.table_owner=myOwner and table_name=mytable_name and partition_name=mypartition_name;
rq:='select '||cvar||' from dual';
execute immediate rq into cDate;
return cdate;
EXCEPTION
WHEN infiniteValue
then return'01 jan 3000';
when others
then return null;
end longToDate;
Ant the view is something like this
create or replace view last_35 as
with maxdate as
(select longToDate(p.table_owner,p.table_name,p.partition_name) mydate,
rank()over(order by p.partition_position desc) mypos,
p.* from all_tab_partitions p
where p.table_name='MY_TABLE'
)
select /*+full(a)*/* from MY_TABLE a, maxdate
where MY_TABLE.partition_name>maxdate.mydate
and maxdate.mypos=35