In the following PL/SQL block, a bind variable is used in the WHERE clause:
declare
symbol varchar2(6) := 'EPIC';
begin
execute immediate 'delete from stock where symbol = :symbol'
using symbol;
end;
/
This block executes successfully, however, something like the following will fail:
declare
symbol varchar2(15) := 'employees';
begin
execute immediate 'delete from :symbol where last_name = ''Kochar'''
using symbol
end;
/
My question is: can we use bind variables in any other context besides passing a value to a WHERE clause like in the first example?
You can bind into your SQL statement only those expressions(literals,
variables, complex expressions) that replace placeholders for data
values inside the dynamic string. you cannot bind in the names of
schema elements(tables, columns, etc) or entrie chunks of the SQL
statement. For those parts of your string, you must use
concatenation(operator)
So Use as in the following :
SQL> create table employees(empid int,last_name varchar2(50));
Table created
SQL> insert into employees values(111,'Kochar');
1 row inserted
SQL> select * from employees;
EMPID LAST_NAME
----- ----------
111 Kochar
SQL>
SQL> declare
2 symbol varchar2(15) := 'employees';
3 begin
4 execute immediate 'delete '||symbol||' where last_name = ''Kochar''';
5 end;
6 /
PL/SQL procedure successfully completed
SQL> select * from employees;
EMPID LAST_NAME
----- ----------
-- i.e. no row(s) returned.
Bind Variables is only transmit values .
It allow to reuse the same query , but with different values .
A table name is not a value .
Related
Table 1
ID
----------
1
2
3
4
5
Table 2
ID Desc
------------------------------
A1 Apple
A2 Pear
A3 Orange
I am trying to create a Function in Oracle, so that it add the prefix 'A' in Table 1, and after that I want to look up in Table 2 to get the DESC returned. It has to be a function.
Thank you!!!
You may use the following for creation of such a function :
Create or Replace Function Get_Fruit( i_id table2.description%type )
Return table2.description%type Is
o_desc table2.description%type;
Begin
for c in ( select description from table2 where id = 'A'||to_char(i_id) )
loop
o_desc := c.description;
end loop;
return o_desc;
End;
where
no need to include exception handling, because of using cursor
instead of select into clause.
using table_name.col_name%type for declaration of data types for
arguments or variables makes the related data type of the columns
dynamic. i.e. those would be able to depend on the data type of the
related columns.
the reserved keywords such as desc can not be used as column names
of tables, unless they're expressed in double quotes ("desc")
To call that function, the following might be preferred :
SQL> set serveroutput on
SQL> declare
2 i_id pls_integer := 1;
3 o_fruit varchar2(55);
4 begin
5 o_fruit := get_fruit( i_id );
6 dbms_output.put_line( o_fruit );
7 end;
8 /
Apple
PL/SQL procedure successfully completed
I am not sure with your question- Are you trying to achieve something like this:-
CREATE OR REPLACE FUNCTION Replace_Value
(
input_ID IN VARCHAR2
) RETURN VARCHAR2
AS
v_ID varchar(2);
BEGIN
begin
SELECT distinct a.ID into v_id from Table 2 a where a.ID in (select 'A'||b.id from table1 b where b.id=input_ID);
exception
when others then
dbms_output.put_line(sqlcode);
end;
RETURN v_id;
END Replace_Value;
Are you trying for something like this?
CREATE OR replace FUNCTION replace_value (table_name IN VARCHAR2,
input_id IN INTEGER)
RETURN VARCHAR2
AS
v_desc VARCHAR(20);
BEGIN
SELECT descr
INTO v_desc
FROM table2
WHERE id = 'A' || input_id
AND ROWNUM = 1; -- only needed if there are multiple rows for each id.
RETURN v_desc;
END replace_value;
You may also add an exception handling for NO_DATA_FOUND or INVALID_NUMBER
My test function is this
CREATE OR REPLACE FUNCTION MULTI_VAL
(MYNAME OUT EMP2017.ENAME%TYPE)
RETURN NUMBER AS
MYSAL EMP2017.SAL%TYPE;
BEGIN
SELECT SAL, ENAME INTO MYSAL, MYNAME FROM EMP2017 ;
RETURN MYSAL;
END;
/
When I run it like
variable mynm varchar2(20)
SELECT MULTI_VAL(:mynm) FROM dual;
it gives this error
ERROR at line 1:
ORA-06553: PLS-561: character set mismatch on value for parameter 'MYNAME'
The error you get now indicates a datatype mismatch.
However there is a fundamental problem with your code. We cannot use functions which have OUT parameters in SQL. So once you have fixed the datatype issue you will get this error: ORA-06572: Function MULTI_VAL has out arguments.
You can run it like this:
declare
n varchar2(20);
x number;
begin
x := multi_val(n);
end;
/
Generally, functions with OUT parameters are considered bad practice. The syntax allows them, but the usage is hard to understand. It's better to use a procedure with two OUT parameters (because we can only call the program in PL/SQL anyway) or else have the function return a user-defined type.
CREATE TABLE EMP2017(ENAME VARCHAR2(10),SAL NUMBER);
INSERT INTO EMP2017 VALUES ('SMITH',5000);
INSERT INTO EMP2017 VALUES ('JOHNS',1000);
COMMIT;
CREATE TYPE RET_MULT AS OBJECT
(ENAME VARCHAR2(10),SAL NUMBER);
CREATE TYPE T_RET_MULT AS TABLE OF RET_MULT;
CREATE OR REPLACE FUNCTION MULTI_VAL RETURN T_RET_MULT PIPELINED IS
MYSAL RET_MULT;
BEGIN
FOR I IN(SELECT SAL, ENAME FROM EMP2017) LOOP
MYSAL := RET_MULT(I.ENAME,I.SAL);
PIPE ROW(MYSAL);
END LOOP ;
RETURN ;
END;
SELECT * FROM TABLE(MULTI_VAL());
I think this question can be solved without using pipeline functions. Just like this. All pre required data as described #Sedat.Turan except function. Sorry for copy/past.
CREATE TABLE EMP2017(ENAME VARCHAR2(10),SAL NUMBER);
INSERT INTO EMP2017 VALUES ('SMITH',5000);
INSERT INTO EMP2017 VALUES ('JOHNS',1000);
COMMIT;
CREATE TYPE RET_MULT AS OBJECT
(ENAME VARCHAR2(10),SAL NUMBER);
CREATE TYPE T_RET_MULT AS TABLE OF RET_MULT;
create or replace function MULTI_VAL return T_RET_MULT is
RET_SET T_RET_MULT;
begin
select RET_MULT(ENAME, SAL) bulk collect into RET_SET from EMP2017;
return RET_SET;
end;
In oracle PLSQL , how to pass a column name and column value to a procedure .
The procedure executes select command based on the where clause
such that Select * from FOO where columnname=columnnvalue
and the procedure stores the resultset (refcursor) in a OUT parameter.
here columnname and columnvalue are passed by user
As i can see you have not shared any inputs. I have tried to replicate
scenario as per your requirements. Please check below snippet. Hope it
helps
set serveroutput on;
CREATE OR REPLACE PROCEDURE USER_INPUT_PROC(
p_col_name_input IN VARCHAR2,
p_col_val_input IN VARCHAR2,
p_lst_out OUT sys_refcursor )
AS
lv_col VARCHAR2(10000 CHAR);
BEGIN
NULL;
SELECT DECODE(p_col_name_input,'empno',' AND EMPNO = '||''''||p_col_val_input||'''','ename',' AND ENAME = '||''''||p_col_val_input||'''','')
INTO lv_col
FROM DUAL;
OPEN p_lst_out FOR 'SELECT * FROM EMP
WHERE 1 = 1 '||lv_col;
END;
To do this safely you need to use the dbms_sql package. The coding becomes pretty involved.
I am using Toad. I have a declaration of a table in a package as follows:
TYPE MyRecordType IS RECORD
(ID MyTable.ID%TYPE
,FIELD1 MyTable.FIELD1%TYPE
,FIELD2 MyTable.FIELD2%TYPE
,FIELD3 MyTable.FIELD3%TYPE
,ANOTHERFIELD VARCHAR2(80)
);
TYPE MyTableType IS TABLE OF MyRecordType INDEX BY BINARY_INTEGER;
There is a procedure (lets say MyProcedure), that is using an object of this table type as input/output. I want to run the procedure and see the results (how the table is filled). So I am thinking I will select the results from the table:
declare
IO_table MyPackage.MyTableType;
begin
MyPackage.MyProcedure (IO_table
,parameter1
,parameter2
,parameter3);
select * from IO_table;
end;
I get the message:
Table or view does not exist (for IO_table). If I remove the select line, the procedure runs successfully, but I cannot see its results. How can I see the contents of IO_table after I call the procedure?
You cannot see the results for a PL/SQL table by using Select * from IO_table
You will need to loop through the collection in the annonymous block.
do something like, given in pseudo code below...
declare
IO_table MyPackage.MyTableType;
l_index BINARY_INTEGER;
begin
MyPackage.MyProcedure (IO_table
,parameter1
,parameter2
,parameter3);
l_index := IO_table.first;
While l_index is not null
loop
dbms_output.put_line (IO_table(l_index).id);
.
.
.
.
l_index :=IO_table.next(l_index_id);
end loop;
end;
You have to do it like this:
select * from TABLE(IO_table);
and, of course you missed the INTO or BULK COLLECT INTO clause
1) You can not use associated arrays in SELECT statement, Just nested tables or varrays declared globally.
2) You should use TABLE() expression in SELECT statement
3) You can't simply use SELECT in PL/SQL code - cursor FOR LOOP or REF CURSOR or BULK COLLECT INTO or INTO must be used.
4) The last but not least - please study the manual:
http://docs.oracle.com/cd/B28359_01/appdev.111/b28371/adobjcol.htm#ADOBJ00204
Just an example:
SQL> create type t_obj as object( id int, name varchar2(10));
2 /
SQL> create type t_obj_tab as table of t_obj;
2 /
SQL> var rc refcursor
SQL> declare
2 t_var t_obj_tab := t_obj_tab();
3 begin
4 t_var.extend(2);
5 t_var(1) := t_obj(1,'A');
6 t_var(2) := t_obj(2,'B');
7 open :rc for select * from table(t_var);
8 end;
9 /
SQL> print rc
ID NAME
---------- ----------
1 A
2 B
In the SQL Server, I can define local variables like this.
declare #id number := 1000
select * from tbl_A where id = #id;
select * from tbl_B where id = #id;
It is very convenient.
I tried to do same thing in PL/SQL but it doesn't work.
DECLARE id number;
select 1000 into id from dual;
Do you know how to do something similar? The simplest method is my objective.
If you want to define a local variable in PL/SQL, you need a complete PL/SQL block
DECLARE
id NUMBER;
BEGIN
SELECT 1000
INTO id
FROM dual;
END;
or just
DECLARE
id NUMBER := 1000;
BEGIN
<<do something that uses the local variable>>
END;
If you want to declare a variable in SQL*Plus
SQL> variable id number
SQL> begin
select 1000 into :id from dual;
end;
/
SQL> print id
ID
----------
1000
SQL> SELECT * FROM tbl_a WHERE id = :id
An alternative to DECLARE Block is to use a WITH Clause:
WITH my_params AS (
SELECT 123 AS min_id FROM DUAL
)
SELECT *
FROM some_table
WHERE id > (SELECT min_id FROM my_params)
It is more portable as many vendors support the WITH clause and you can change seamless from parameter to dynamic value. For example:
WITH my_params AS (
SELECT min(id) AS min_id FROM some_id_table
)
SELECT *
FROM some_table
WHERE id > (SELECT min_id FROM my_params)
Solution for Oracle SQL
DEF x = foo
SELECT '&x' FROM dual;
The result will be : foo
NB: The variable will keep the value even after execution. To clear variable run UNDEFINE x.
General syntax to declare variable in PL/SQL is
var_nm datatype [NOT NULL := var_value ];
var_nn is the name of the variable.
datatype is a valid PL/SQL datatype.
NOT NULL is an optional specification on the variable which this variable cannot be assigned null value.
var_value or DEFAULT value is also an optional specification, where you can initialize a variable with some specific value.
Each variable declaration is a separate statement and must be terminated by a semicolon.
We can assign value to variables in one of the following two ways -
direct assignment (Eg. var_nm:= var_value;)
Using select from (Eg. SELECT col_nm INTO var_nm FROM tbl_nm [WHERE clause];)
In you case as Justin Cave has already mentioned it can be
DECLARE
id number;
BEGIN
SELECT 1000 into id from dual;
dbms_output.put_line('id : '|| id );
END;
/
OR
DECLARE
id number := 1000;
BEGIN
dbms_output.put_line('id : '|| id );
END;
/
NOTE: '/' i.e Back slash after END keyword indicates to execute the above PL/SQL Block.
(Just stumbled across this thread.) Beginning with SQL*Plus 12.2, you can declare and assign a value at the same time:
SQL> var id number = 1000
SQL> select * from tbl_A where id = :id;
Oracle calls it input binding.
If you must do it in PL/SQL, the answer was given by others.