I made this account just for this question because I'm really not sure how to word it properly for google to pick up on it. So here goes...
I was working on a query for a group project that I was assigned in my database II course. I made 2 and was working on a third when I wanted to see if I could do something like the following.
declare
Emp_ID := 03;
Salary_Increment := 2.0 --constants do not change
Salary_ID := 03;
Current_Salary := 47500
Updated_Salary := Current_Salary * 2.0
BEGIN
dbms_output.put_line('The Employee with the ID of' +Emp_ID 'will receive a 2% bonus.');
dbms_output.put_line('This Employees new salary will be: ' +Updated_Salary ');
end;
I attempted to do this previously but with a more simple code snippet. Figured I would see if I could do this just to simplify how much I have to type out.
TL;DR - Can I use a reference like +Emp_ID in a Oracle SQL dbms output?
In oracle, There are two ways of concating the string.
using || operator.
Like this.
dbms_output.put_line('The Employee with the ID of' || Emp_ID || ' will receive a 2% bonus.');
using CONCAT method.
Like this:
dbms_output.put_line(CONCAT(CONCAT('The Employee with the ID of', Emp_ID), ' will receive a 2% bonus.'));
Note that CONCAT uses only two parameter as input. So you need to use it multiple times to concat more than 2 strings.
Cheers!!
The string concatenation operator is || in PL/SQL, so you'd want to write
dbms_output.put_line('The Employee with the ID of' || Emp_ID || ' will receive a 2% bonus.');
Related
I want to printout a Dynamic built query. Yet I am stuck at variable declaration; Error At line 2.
I need the maximum size for these VARCHAR2 variables.
Do I have a good overall structure ?
I use the result of the WITH inside the dynamic query.
DECLARE l_sql_query VARCHAR2(2000);
l_sql_queryFinal VARCHAR2(2000);
with cntp as (select distinct
cnt.code code_container,
*STUFF*
FROM container cnt
WHERE
cnt.status !='DESTROYED'
order by cnt.code)
BEGIN
FOR l_counter IN 2022..2032
LOOP
l_sql_query := l_sql_query || 'SELECT cntp.code_container *STUFF*
FROM cntp
GROUP BY cntp.code_container ,cntp.label_container, cntp.Plan_Classement, Years
HAVING
cntp.Years=' || l_counter ||'
AND
/*stuff*/ TO_DATE(''31/12/' || l_counter ||''',''DD/MM/YYYY'')
AND SUM(cntp.IsA)=0
AND SUM(cntp.IsB)=0
UNION
';
END LOOP;
END;
l_sql_queryFinal := SUBSTR(l_sql_query, 0, LENGTH (l_sql_query) – 5);
l_sql_queryFinal := l_sql_queryFinal||';'
dbms_output.put_line(l_sql_queryFinal);
The code you posted has quite a few issues, among them:
you've got the with (CTE) as a standlone fragment in the declare section, which isn't valid. If you want it to be part of the dynamic string then put it in the string;
your END; is in the wrong place;
you have – instead of -;
you remove the last 5 characters, but you end with a new line, so you need to remove 6 to include the U of the last UNION;
the line that appens a semicolon is itself missing one (though for dynamic SQL you usually don't want a semicolon, so the whole line can probably be removed);
2000 characters is too small for your example, but it's OK with the actual maximum of 32767.
DECLARE
l_sql_query VARCHAR2(32767);
l_sql_queryFinal VARCHAR2(32767);
BEGIN
-- initial SQL which just declares the CTE
l_sql_query := q'^
with cntp as (select distinct
cnt.code code_container,
*STUFF*
FROM container cnt
WHERE
cnt.status !='DESTROYED'
order by cnt.code)
^';
-- loop around each year...
FOR l_counter IN 2022..2032
LOOP
l_sql_query := l_sql_query || 'SELECT cntp.code_container *STUFF*
FROM cntp
GROUP BY cntp.code_container ,cntp.label_container, cntp.Plan_Classement, Years
HAVING
cntp.Years=' || l_counter ||'
AND
MAX(TO_DATE(cntp.DISPOSITION_DATE,''DD/MM/YYYY'')) BETWEEN TO_DATE(''01/01/'|| l_counter ||''',''DD/MM/YYYY'') AND TO_DATE(''31/12/' || l_counter ||''',''DD/MM/YYYY'')
AND SUM(cntp.IsA)=0
AND SUM(cntp.IsB)=0
UNION
';
END LOOP;
l_sql_queryFinal := SUBSTR(l_sql_query, 0, LENGTH (l_sql_query) - 6);
l_sql_queryFinal := l_sql_queryFinal||';';
dbms_output.put_line(l_sql_queryFinal);
END;
/
db<>fiddle
The q[^...^] in the first assignment is the alternative quoting mechanism, which means you don't have to escape (by doubling-up) the quotes within that string, around 'DESTYORED'. Notice the ^ delimiters do not appear in the final generated query.
Whether the generated query actually does what you want is another matter... The cntp.Years= part should probably be in a where clause, not having; and you might be able to simplify this to a single query instead of lots of unions, as you're already aggregating. All of that is a bit beyond the scope of your question though.
Is there a way to put the maximum size "automaticcaly" like "VARCHAR2(MAX_STRING_SIZE) does it work ?
No. And no.
The maximum size of varchar2 in PL/SQL is 32767. If you want to hedge against that changing at some point in the future you can declare a user-defined subtype in a shared package ...
create or replace package my_subtypes as
subtype max_string_size is varchar2(32767);
end my_subtypes;
/
... and reference that in your program...
DECLARE
l_sql_query my_subtypes.max_string_size;
l_sql_queryFinal my_subtypes.max_string_size;
...
So if Oracle subsequently raises the maximum permitted size of a VARCHAR2 in PL/SQL you need only change the definition of my_subtypes.max_string_size for the bounds to be raised wherever you used that subtype.
Alternatively, just use a CLOB. Oracle is pretty clever about treating a CLOB as a VARCHAR2 when its size is <= 32k.
To solve your other problem you need to treat the WITH clause as a string and assign it to your query variable.
l_sql_query my_subtypes.max_string_size := q'[
with cntp as (select distinct
cnt.code code_container,
*STUFF*
FROM container cnt
WHERE cnt.status !='DESTROYED'
order by cnt.code) ]';
Note the use of the special quote syntax q'[ ... ]' to avoid the need to escape the quotation marks in your query snippet.
A dynamic string query do not access a temp table ?
Dynamic SQL is a string containing a DML or DDL statement which we execute with EXECUTE IMMEDIATE or DBMS_SQL commands. Otherwise it is exactly the same as static SQL, it doesn't behave any differently. In fact the best way to write dynamic SQL is to start by writing the static statement in a worksheet, make it correct and then figure out which bits need to be dynamic (variables, placeholders) and which bits remain static (boilerplate). In your case the WITH clause is a static part of the statement.
As has already been pointed out, you seem to have misunderstood what a with clause is: it's a clause of a SQL statement, not a procedural declaration. My definition, it must be followed by select.
But also, as a general rule, I would recommend avoiding dynamic SQL when possible. In this case, if you can simulate a table with the range of years you want, you can join instead of having to run the same query multiple times.
The easy trick to doing that is to use Oracle's connect by syntax to use a recursive query to produce the expected number of rows.
Once you've done that, adding this table as a join pretty trivially:
WITH cntp AS
(
SELECT DISTINCT code code_container,
[additional columns]
FROM container
WHERE status !='DESTROYED') cntc,
(
SELECT to_date('01/01/'
|| (LEVEL+2019), 'dd/mm/yyyy') AS start_date,
to_date('31/12/'
|| (LEVEL+2019), 'dd/mm/yyyy') AS end_date,
(LEVEL+2019) AS year
FROM dual
CONNECT BY LEVEL <= 11) year_table
SELECT cntp.code_container,
[additional columns]
FROM cntp
join year_table
ON cntp.years = year_table.year
GROUP BY [additional columns],
years,
year_table.start_date,
year_table.end_date
HAVING max(to_date(cntp.disposition_date,''dd/mm/yyyy'')) BETWEEN year_table.start_date AND year_table.end_date
AND SUM(cntp.isa)=0
AND SUM(cntp.isb)=0
(This query is totally untested and may not actually fulfill your needs; I am providing my best approximation based on the information available.)
Create a dynamic procedure that will change the contents of any column for any row in the AA_EMPLOYEE table using the employee id. i.e.
BEGIN
dyn_aa_employee('emp_dob', '01-jan-18', 110);
END;
Will change the date of birth for employee ID 110
CREATE OR REPLACE PROCEDURE dyn_aa_employee
(p_col VARCHAR2,
p_dob IN aa_employee.emp_dob%TYPE,
p_id NUMBER)
IS
BEGIN
EXECUTE IMMEDIATE 'UPDATE aa_employee
SET '|| p_col ||' = :ph_dob
WHERE EMP_NUM = :ph_id'
USING p_dob, p_id;
BEGIN
dyn_aa_employee('emp_dob', '01-jan-18', 110);
END;
The top code has to work for the bottom code. The issue is it's changing the emp dob to 01-jan-0018, however I want it to change to exactly 01-jan-18.
My professor gave me a 0 for this assignment I'm just trying to figure out what I did wrong.
Assuming that aa_employee.emp_dob is of type date AND assuming that by '01-jan-18' you mean January 1st, 2018, either you do this:
BEGIN
dyn_aa_employee('emp_dob', date '2018-01-01', 110);
END;
or you could change your procedure to:
CREATE OR REPLACE PROCEDURE dyn_aa_employee (
p_col VARCHAR2,
p_dob IN aa_employee.emp_dob%TYPE,
p_id NUMBER)
IS
BEGIN
EXECUTE IMMEDIATE
'UPDATE aa_employee SET ' || p_col || ' = :ph_dob WHERE EMP_NUM = :ph_id'
USING TO_DATE (p_dob, 'DD-MON-YY'), p_id;
END;
It would be interesting to see the actual assignment, though. It's a rather confused scenario overall and I don't see how it teaches you much except to identify several things you probably shouldn't do.
Well first off you didn't specify the date format you were passing. Therefore accepting whatever format the professor had setup. This is a bad plan, to be safe always specify your date format and don't depend on the default. Defaults can and are changed too often. This is a good lesson why you should always specify the actual date format you're using. Try the following to see the difference:
with ds as
(select '01-jan-18' dt_stg from dual)
select to_date(dt_stg), to_date(dt_stg, 'dd-mon-rr') from ds;
Secondly, seems the assignment was to create a procedure that could update any column. This procedure can update only a column having the same type as "aa_employee.emp_dob%TYPE",presumable a date, but it cannot update any other column type.
Finally, if your trying to figure out what professor thinks you did wrong, then try something strange: ask your professor!
I have a table as shown below. This table will be generated dynamically and I have no prior idea about what value it is going to hold.
------------------------------------------
TABLE_NAME COLUMN_NAME CHAR_LENGTH
------------------------------------------
EMPLOYEE COL1 100
EMPLOYEE COL2 200
EMPLOYEE COL3 300
EMPLOYEE COL4 400
Based on this table, I want to build a query in such a way that it would give me those columns, that contains data having char length greater than CHAR_LENGTH column value.
For example if COL2 contains data having char length 500 (>200), then query would give me COL2.
I don't have any draft code to show my attempt, as I have no idea how would I do this.
I don't think this is possible in pure SQL due to the dynamic nature of your requirement. You'll need some form of PL/SQL.
Assuming you're ok with simply outputting the desired results, here is a PL/SQL block that will get the job done:
declare
wExists number(1);
begin
for rec in (select * from your_dynamic_table)
loop
execute immediate 'select count(*)
from dual
where exists (select null
from ' || rec.table_name || ' t
where length(t.' || rec.column_name || ') > ' || rec.char_length || ')'
into wExists;
if wExists = 1 then
dbms_output.put_line(rec.column_name);
end if;
end loop;
end;
You'll also notice the use of the exists clause to optimize the query, so as not to iterate over the whole table unnecessarily, when possible.
Alternatively, if you want the results to be queryable, you can consider converting the code to a pipelined function.
select column_name
from (
select statement that builds the table output
) A
where char_length<length(column_name)
will that help?
You would need a procedure to achieve the same :
Here I am treating the all_tab_columns table in Oracle, which is a default table with much similar structure as your reference example.(Try select * from all_tab_columns). The structure of all_tab_columns is much like yours, except that you will never find a varchar record whose value has exceeded its data length(obvious database level constraint). Date fields may exceed data length, and do reflect in this procedure's output. I am searching all columns in EMPLOYEES whose size exceeds what is specified.
DECLARE
cursor c is select column_name,data_length,table_name from all_tab_columns where table_name=:Table_name;
V_INDEX_NAME all_tab_columns.column_name%type;
v_data_length all_tab_columns.data_length%type;
V_NUMBER PLS_INTEGER;
v_table_name all_tab_columns.table_name%type;
BEGIN
open c;
LOOP
FETCH c into v_index_name,v_data_length,v_table_name;
EXIT when c%NOTFOUND;
v_number :=0;
execute immediate 'select count(*) from '|| :Table_name ||' where length('||v_index_name||')>'||v_data_length into v_number;
if v_number>1 then
dbms_output.put_line(v_index_name||' has values greater than specified'||' '||V_INDEX_NAME||' '||v_data_length);
end if;
END LOOP;
close c;
END;
/
Replace all_tab_columns and its respective columns with the column name of your table.
DEFECTS : The table name is hardcoded. Trying to make the code generic execute immediate or any other trick. Will achieve soon.
EDIT : Defect fixed.
Here's a question for you all, is there any way to make the PL/SQL code below work by dynamically replacing the column_name in the cursor.column_name syntax? I know I'm confusing the pl/sql engine, but I'm not entirely sure on how to fix this...
Currently I get the error below, but I think the actual issue is that the pl/sql engine doesn't know how to interpret TRIM (e_rec.v_temp_column_name) :
"[Error] PLS-00302 (133: 26): PLS-00302: component
'V_TEMP_COLUMN_NAME' must be declared"
Parameter: x_person_rec IN OUT xxsome_table%ROWTYPE
v_temp_column_name dba_tab_columns.column_name%TYPE;
...
BEGIN
FOR e_rec IN (SELECT * FROM xxsome_table WHERE ..)
LOOP
--LOG (3, 'Loading/Sanitizing Header Record');
FOR col IN (SELECT column_name
FROM dba_tab_columns
WHERE table_name = UPPER ('xxsome_table'))
LOOP
--LOG (3, 'Sanitizing Column Name: ' || col.column_name);
v_temp_column_name := col.column_name;
x_person_rec.v_temp_column_name := TRIM (e_rec.v_temp_column_name);
END LOOP;
END LOOP;
...
I've tried doing this (which results in different error): x_person_rec.col.column_name := TRIM (e_rec.col.column_name);
No, you can't and you are indeed confusing the PL/SQL engine. The problem is that v_temp_column_name is a character, so TRIM (e_rec.v_temp_column_name) is evaluated as TRIM (e_rec.'v_temp_column_name'), which doesn't make any sense.
The best things to do, if trailing whitespace is a problem, is to ensure that all data being put into your database is trimmed by your application/ETL processes at the time. If you can't do this then use a trigger to ensure that it happens inside the database. If it's a really bad problem you can even enforce check constraints to stop it from ever happening.
Now, to sort of answer your question, there's no need to do anything dynamically here. Your cursor may be implicit but it's not been dynamically generated. You know every column in the table so be a little less lazy and type them all out.
FOR e_rec IN (SELECT trim(col1) as col1
, trim(col2) as col2
FROM xxsome_table WHERE ...
If you can't fix your data (or if it's not broken!) then this is easily the simplest way to do it.
To actually answer your question, you can dynamically build your SELECT statement using the same techniques you're using here...
declare
l_cols varchar2(4000);
l_curs sys_refcursor;
begin
select wm_concat('trim(' || column_name || ')')
into l_cols
from user_tab_columns
where table_name = 'XXSOME_TABLE'
;
open l_curs for
' select ' || l_cols || ' from xxsome_table where ...';
loop
...
end loop;
end;
/
As you're on 10g you can't use the excellent LISTAGG(), but there are plenty of other string aggregation techniques. Please note that if the resulting string is greater than 4,000 bytes, you'll have to loop rather than generating the column list in a single SQL statement.
P.S., if these columns are CHAR(n) then you'll have to trim them every time you select. It might be worth changing them to VARCHAR2(n)
Am having a table with 30+ columns. Would like to append all the column data.
I'm currently using multiple concatenate operators to achieve this in Oracle.
Example :
SELECT C1.data || '' || C2.data ||..........Cm.data
FROM C
Is there any other way of doing it with out using the '||' - concatenate operator multiple times ? I want to achieve this using query. (Not interested in post processing using any language) Any assistance would be of great help.
Try something like this. Anyway you'll be mentioning all the columns you needed.
declare
stmt varchar2(300);
v_char char(10):=',||" "||,';
begin
stmt:='select 1,2,3,4 from tab';
dbms_output.put_line(stmt);
select replace(stmt,',',v_char) into stmt from dual;
dbms_output.put_line(stmt);
execute immediate stmt; // you can add this after verifying your query
end;
OUTPUT:
select 1,||" "||, 2,||" "||, 3,||" "||, 4 from tab;