oracle sql dynamic query to select column in cursor - oracle

I've declared the below cursor and variables:
l_level VARCHAR2(100);
l_level_value VARCHAR2(100);
l_select_clause CLOB;
CURSOR l_data IS
SELECT LEVEL1, LEVEL2, LEVEL3
FROM LEVELS;
Then I loop through the cursor:
FOR c1line IN l_data
LOOP
CASE WHEN c1line.LEVEL1 IS NULL THEN l_level := 'c1line.LEVEL2'
WHEN c1line.LEVEL2 IS NULL THEN l_level := 'c1line.LEVEL3'
WHEN c1line.LEVEL3 IS NULL THEN l_level := 'c1line.LEVEL4'
ELSE l_level := NULL
END CASE;
END LOOP;
l_select_clause := 'SELECT ' || l_level || ' INTO l_level_value FROM dual;';
EXECUTE IMMEDIATE l_select_clause;
And then I have some other statements that execute depending on what is selected into the variable l_level_value
My problem is that when execute my procedure I get the following error:
ORA-00904: "C1LINE"."LEVEL2": invalid identifier
ORA-06512: at "MY_PROCEDURE", line 110
ORA-06512: at line 2
Does anyone know what I have done wrong?
Thanks

About the Actual Error c1line.LEVEL1 , you open the cursor dynamically? it seems valid in thee code you have shown
Then..
EXECUTE IMMEDIATE Accepts bind variable, whereas INTO should be after Execution only. To mention, Semicolon (;) is not needed in the Query String
l_select_clause := 'SELECT ' || l_level || ' FROM dual';
EXECUTE IMMEDIATE l_select_clause INTO l_level_value;

My Question is, do you really need dynamic script? I mean same operation can be performed as
FOR c1line IN l_data
LOOP
CASE WHEN c1line.LEVEL1 IS NULL THEN l_level_value := c1line.LEVEL2
WHEN c1line.LEVEL2 IS NULL THEN l_level_value := c1line.LEVEL3
WHEN c1line.LEVEL3 IS NULL THEN l_level_value := c1line.LEVEL4
ELSE l_level_value := NULL
END CASE;
END LOOP;
Why taking two steps? First assign the value to l_level and then assign same value to l_level_value? That too using dynamic scripts?
Always remember, dynamic script should be the last and last options. You should avoid it.

Related

Oracle pl/sql Array

let's see if somebody can help me, I need to delete rows from different tables and I did think to do it using an array so i wrote this :
DECLARE
TYPE mytype_a IS TABLE OF VARCHAR2(32) INDEX BY BINARY_INTEGER;
mytype mytype_a;
BEGIN
mytype(mytype.count + 1) := 'MYTABLE';
FOR i IN 1 .. mytype.count
LOOP
DELETE mytype(i) WHERE valid = 'N';
END LOOP;
END;
Trying to run this piece of code using sqldeveloper I get the ORA-00933 command not properly ended, if I put directly the table name it works, what am I doing wrong?
Thank you.
Thank you very much guys, it works perfectly.
This is not the correct approach. You have to use Dynamic SQL for this -
DECLARE
type mytype_a is table of varchar2(32) index by binary_integer;
mytype mytype_a;
stmt varchar(500) := NULL;
BEGIN
mytype (mytype.count + 1) := 'MYTABLE';
for i in 1..mytype.count loop
stmt := 'DELETE FROM ' || mytype(i) || ' where valid =''N''';
EXECUTE IMMEDIATE stmt;
end loop;
END;
You would need to use dynamic SQL, concatenating the table name from the collection into the statement, inside your loop:
execute immediate 'DELETE FROM ' || mytype(i) || ' where valid = ''N''';
Or you can put the statement into a variable so you can display it for debugging purposes, and then execute that, optionally with a bind variable for the valid value:
stmt := 'DELETE FROM ' || mytype(i) || ' where valid = :valid';
dbms_output.put_line(stmt);
execute immediate stmt using 'N';
dbms_output.put_line('Deleted ' || sql%rowcount || ' row(s)');
... which I've made also display how many rows were deleted from each table. Note though that you shoudln't rely on the caller being able to see anything printed with dbms_output - it's up to the client whether it shows it.
The whole anonymous block would then be:
DECLARE
type mytype_a is table of varchar2(32) index by binary_integer;
mytype mytype_a;
stmt varchar2(4000);
BEGIN
mytype (mytype.count + 1) := 'MYTABLE';
for i in 1..mytype.count loop
stmt := 'DELETE FROM ' || mytype(i) || ' where valid = :valid';
dbms_output.put_line(stmt);
execute immediate stmt using 'N';
dbms_output.put_line('Deleted ' || sql%rowcount || ' row(s)');
end loop;
END;
/
You could use a built-in collection type to simplify it even further.
db<>fiddle showing some options.
Hopefully this doesn't apply, but if you might have any tables with quoted identifiers then you would need to add quotes in the dynamic statement, e.g.:
stmt := 'DELETE FROM "' || mytype(i) || '" where valid = :valid';
... and make sure the table name values in your collection exactly match the names as they appear in the data dictionary (user_tables.table_name).

ORA-01008: not all variables bound - "not all variables bound"

This is my plsql block, dynamic SQL. I can't find a reason why it comes up with an error 'no ORA-01008: not all variables bound ORA-06512: at line 23'.
I can't find the error on my EXECUTE IMMEDIATE statement.
DECLARE
form_name VARCHAR2(225) := 'MUST AS';
ad_no VARCHAR2(225) := :ad_no;
sql_stmt VARCHAR2(4000);
sql_output VARCHAR2(4000);
db_table VARCHAR(225) := inp_reminder_pkg.form_db_table(form_name);
col_id VARCHAR(225) := inp_reminder_pkg.get_col_id(form_name);
BEGIN
sql_stmt := '
SELECT :1
FROM #tableName
WHERE advno = :2
AND created = ( SELECT MAX(CREATED)
FROM #tableName
WHERE advno = :2 )'
;
sql_stmt := replace(sql_stmt, '#tableName', db_table);
EXECUTE IMMEDIATE sql_stmt
INTO sql_output
USING col_id, ad_no;
dbms_output.put_line(sql_output);
EXCEPTION
WHEN no_data_found THEN
dbms_output.put_line('no-data');
END;
Let me know what I am missing. thanks you
There are three bind variables (even though two have the same name), you need to send 3 arguments for them in the execute immediate statement.
Note that you probably didn’t mean for the column name to be input as a bind variable, this is something that has to be dynamically executed if you want to have a variable column being selected.
There are two problems with your code:
The dynamic query has two instances of the placeholder :advno so you need to pass two values in the USING clause. Yes this is a bit rubbish, but I guess Oracle felt parsing dynamic SQL is hard enough without asking the compiler to match placeholder names.
We can't pass column names or other identifiers as parameters. We have to break up the statement to reference the column name variable. For the same reason you have the replace() call to substitute the table name.
So you need to change your procedure so it looks like this:
DECLARE
form_name VARCHAR2(225) := 'MUST AS';
ad_no VARCHAR2(225) := :ad_no;
sql_stmt VARCHAR2(4000);
sql_output VARCHAR2(4000);
db_table VARCHAR(225) := inp_reminder_pkg.form_db_table(form_name);
col_id VARCHAR(225) := inp_reminder_pkg.get_col_id(form_name);
BEGIN
sql_stmt := '
SELECT ' || col_id || '
FROM #tableName
WHERE advno = :2
AND created = ( SELECT MAX(CREATED)
FROM #tableName
WHERE advno = :2 )'
;
sql_stmt := replace(sql_stmt, '#tableName', db_table);
EXECUTE IMMEDIATE sql_stmt
INTO sql_output
USING ad_no, ad_no;
dbms_output.put_line(sql_output);
EXCEPTION
WHEN no_data_found THEN
dbms_output.put_line('no-data');
END;

How to handle cursor exception when the select query returns "zero" records

How to handle cursor exception when the select query returns "zero" records
I have a cursor in a procedure, and after cursor initialization I'm iterating through the cursor to access the data from it.
But the problem is when the cursor select query returns 0 records then it throws exception
ORA-06531: Reference to uninitialized collection.
How to handle this exception?
---procedure code
create or replace PROCEDURE BIQ_SECURITY_REPORT
(out_chr_err_code OUT VARCHAR2,
out_chr_err_msg OUT VARCHAR2,
out_security_tab OUT return_security_arr_result ,
)
IS
l_chr_srcstage VARCHAR2 (200);
lrec return_security_report;
CURSOR cur_security_data IS
SELECT
"ID" "requestId",
"ROOM" "room",
"FIRST_NAME" "FIRST_NAME",
"LAST_NAME" "LAST_NAME",
FROM
"BI_REQUEST_CATERING_ACTIVITY" ;
TYPE rec_security_data IS TABLE OF cur_security_data%ROWTYPE
INDEX BY PLS_INTEGER;
l_cur_security_data rec_security_data;
begin
OPEN cur_security_data;
LOOP
FETCH cur_security_data
BULK COLLECT INTO l_cur_security_data
LIMIT 1000;
EXIT WHEN l_cur_security_data.COUNT = 0;
lrec := return_security_report();
out_security_tab := return_security_arr_result(return_security_report());
out_security_tab.delete;
FOR i IN 1 .. l_cur_security_data.COUNT
LOOP
BEGIN
l_num_counter := l_num_counter + 1;
lrec := return_security_report();
lrec.requestid := l_cur_security_data(i).requestId ; lrec.room := l_cur_security_data(i).room ; lrec.firstName := l_cur_security_data(i).firstName ;
IF l_num_counter > 1
THEN
out_security_tab.extend();
out_security_tab(l_num_counter) := return_security_report();
ELSE
out_security_tab := return_security_arr_result(return_security_report());
END IF;
out_security_tab(l_num_counter) := lrec;
EXCEPTION
WHEN OTHERS
THEN
DBMS_OUTPUT.PUT_LINE('Error occurred : ' || SQLERRM);
END;
END LOOP;
END LOOP;
EXCEPTION
WHEN OTHERS
THEN
DBMS_OUTPUT.PUT_LINE ('HERE INSIIDE OTHERS' || SQLERRM);
END;
Can you please explain how handle it.
You must be using out_security_tab, which is an output parameter in some other code where the procedure is called.
In your procedure, If cursor returns zero rows then the loop will not be executed and your code will not even initialize the out_security_tab which will lead to the error that you are facing.
There is a simple way to avoid:
initialize out_security_tab outside the loop -- which will definitely initialize it
You can create one out variable containing details as Y or N based on if cursor rows count -- Not recommended
Cheers!!

Passing dynamic input parameters to 'execute Immediate'

I have a table where I am storing certain conditions along with input parameters as shown below:
CONDITION | INPUT_PARAMS
---------------------------------------------------------
:p_end_date < :p_start_date | v_end_date, IN v_start_date
:p_joining_day = 'MONDAY' | v_joining_day
I want to use execute immediate to evaluate the conditions.
select condition, input_param
into v_execute_condition, v_input_param
From table;
v_execute_statement :=
'IF '||v_execute_condition ||' '||
'THEN :o_flag := ''Y'';' ||' '||
'ELSE :o_flag := ''N'';' ||' '||
'END IF;';
v_execute_statement := 'BEGIN '||v_execute_statement||' END;';
dbms_output.put_line(v_execute_statement);
EXECUTE IMMEDIATE v_execute_statement USING IN input_param OUT v_flag;
This gives me an error. If I do not pass input parameters dynamically it works.
How can I pass the list of input parameters dynamically?
You can't supply a string list of bind values as a using parameter, so the only way I can see to do this is with nested dynamic SQL calls, which is a bit messy, and means having to declare (and bind) all possible parameters in the inner. nested, dynamic statement.
declare
v_execute_statement varchar2(4000);
v_flag varchar2(1);
v_start_date date := date '2018-01-01';
v_end_date date := date '2018-01-31';
v_joining_day varchar2(9) := 'MONDAY';
begin
-- loop over all rows for demo
for rec in (
select condition, input_params
From your_table
)
loop
v_execute_statement := q'[
DECLARE
v_start_date date := :v_start_date;
v_end_date date := :v_end_date;
v_joining_day varchar2(9) := :v_joining_day;
BEGIN
EXECUTE IMMEDIATE q'^
BEGIN
IF ]' || rec.condition || q'[ THEN
:o_flag := 'Y';
ELSE
:o_flag := 'N';
END IF;
END;^'
USING ]' || rec.input_params || q'[, OUT :v_flag;
END;]';
dbms_output.put_line('Statement: ' || v_execute_statement);
EXECUTE IMMEDIATE v_execute_statement
USING v_start_date, v_end_date, v_joining_day, OUT v_flag;
dbms_output.put_line('Result flag: ' || v_flag);
end loop;
end;
/
I've used the alternative quoting mechanism here to reduce confusion from escaped single quotes. There are two nested levels of quoting - the outer one delimited by q'[...]' and the inner one delimited by q'^...^', but you can use other characters if those are a problem because of your actual table contents. Escaping those quotes for two levels would be quite ugly and hard to follow/get right; and you'd also have to worry about further escaping quotes in your condition strings, which would already be a problem with your existing code for the second sample you provided as that contains a text literal within it.
With your two sample table rows and the dummy date/day values I showed above the output from running that is:
Statement:
DECLARE
v_start_date date := :v_start_date;
v_end_date date := :v_end_date;
v_joining_day varchar2(9) := :v_joining_day;
BEGIN
EXECUTE IMMEDIATE q'^
BEGIN
IF :p_end_date < :p_start_date THEN
:o_flag := 'Y';
ELSE
:o_flag := 'N';
END IF;
END;^'
USING v_end_date, IN v_start_date, OUT :o_flag;
END;
Result flag: N
Statement:
DECLARE
v_start_date date := :v_start_date;
v_end_date date := :v_end_date;
v_joining_day varchar2(9) := :v_joining_day;
BEGIN
EXECUTE IMMEDIATE q'^
BEGIN
IF :p_joining_day = 'MONDAY' THEN
:o_flag := 'Y';
ELSE
:o_flag := 'N';
END IF;
END;^'
USING v_joining_day, OUT :o_flag;
END;
Result flag: Y
The first thing to note in the generated statement is the declare section, which has to list all the possible variable names you might have in input_params, and set them from new bind variables. You must know these already in the main block/procedure, either as local variables or more likely procedure arguments; but they all have the be duplicated here, since at this point you don't know which will be needed.
Then that statement has its own inner dynamic SQL which is essentially what you were originally doing, but concatenates in the input_params string as well as condition.
The important part here is the quoting. In the first one, for example, both :p_end_date and :p_start_date are inside the second level of quotes, within the q'^...^', so they are bound for the inner dynamic SQL, with values from the local v_end_date and v_start_date from that inner execute immediate.
That entire generated block is executed with bind values for all the possible variable names, which provide values for the local variables (via v_start_date date := :v_start_date; etc.) while preserving data types; plus the output flag.
That block then executes its internal execute immediate statement using only the relevant local variables, which now have bound values; and the output flag which is still a bind variable from the outer execute immediate, so the outer block can still see its result.
You can see that the second generated statement uses a different condition and bind variables and values to the first, and the flag is evaluated based on the relevant condition and parameters in each case.
Incidentally, you could remove the duplicate reference to :o_flag (which isn't a problem but I find slightly confusing) by using a case expression instead:
v_execute_statement := q'[
DECLARE
v_start_date date := :v_start_date;
v_end_date date := :v_end_date;
v_joining_day varchar2(9) := :v_joining_day;
BEGIN
EXECUTE IMMEDIATE q'^
BEGIN
:o_flag := CASE WHEN ]' || rec.condition || q'[ THEN 'Y' ELSE 'N' END;
END;^'
USING OUT :v_flag, ]' || rec.input_params || q'[;
END;]';

Oracle dynamic parameters

I'm struggling to create a dynamic sql parametrized query. It involves using 'IS NULL' or 'IS NOT NULL'
Here's a simple pl/sql query:
CREATE OR REPLACE PROCEDURE GET_ALL_INFORMATION
(
"PARAM_START_DATE" IN DATE,
"PARAM_END_DATE" IN DATE,
"PARAM_IS_SUBMITTED" IN NUMBER,
"EXTRACT_SUBMITTED_CONTACTS" OUT sys_refcursor
) IS
sql_stmt VARCHAR2(3000);
PARAM_CONDITION VARCHAR2(20);
BEGIN
IF PARAM_IS_SUBMITTED = 1 THEN
PARAM_CONDITION := 'NOT NULL';
ELSE
PARAM_CONDITION := 'NULL';
END IF;
sql_stmt := ' SELECT
REGISTRATION_NUMBER,
NAME PROVIDER_TYPE,
ORGANIZATION
FROM TABLE_A
WHERE
P.DATE_FINALIZED IS :A;
OPEN EXTRACT_SUBMITTED_CONTACTS FOR sql_stmt USING PARAM_CONDITION;
Whereas the parameter (:A) in (USING PARAM_CONDITION) should have 'NULL' or 'NOT NULL'. It does not seem to work the way I envisioned.
Am I missing something?
As explained by GriffeyDog in a comment above, bind parameters could only be used as place holder for values. Not to replace keywords or identifiers.
However, this is not really an issue here, as you are using dynamic SQL. The key idea ifs that you build your query as a string -- and it will be parsed at run-time by the PL/SQL engine when you invoke EXECUTE or OPEN .. FOR.
Simply said, you need a concatenation -- not a bound parameter:
...
sql_stmt := ' SELECT
REGISTRATION_NUMBER,
NAME PROVIDER_TYPE,
ORGANIZATION
FROM TABLE_A
WHERE
P.DATE_FINALIZED IS ' || PARAM_CONDITION;
-- ^^
OPEN EXTRACT_SUBMITTED_CONTACTS FOR sql_stmt;

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