I have an insert statement that takes all its values from local variables or literal constants:
INSERT INTO SampleTestLimits
(AuditNumber
,LimitNumber
,ComponentRow
,ComponentColumn
--etc
)
SELECT 1
,varLimitNumber
,varComponentRow
,varComponentColumn
--etc
;
but the problem is that I get an error "Missing FROM".
I guessed that this is because there is no table associated with the Select, and I tried ending the query with
FROM DUAL;
but that doesn't work (possibly because DUAL is a single row, single column pseudo-table, or so I understand).
I can do this quite easily in Sql Server, but how can I do what I want to achieve in Oracle?
TIA.
If you want to insert data from local variables you should use the VALUES clause:
INSERT INTO SampleTestLimits
(AuditNumber
,LimitNumber
,ComponentRow
,ComponentColumn
--etc
)
VALUES
(1
,varLimitNumber
,varComponentRow
,varComponentColumn
--etc
);
Related
I have function which returns column names and i am trying to use the column name as part of my select statement, but my results are coming as column name instead of values
FUNCTION returning column name:
get_col_name(input1, input2)
Can И use this query to the results of the column from table -
SELECT GET_COL_NAME(input1,input2) FROM TABLE;
There are a few ways to run dynamic SQL directly inside a SQL statement. These techniques should be avoided since they are usually complicated, slow, and buggy. Before you do this try to find another way to solve the problem.
The below solution uses DBMS_XMLGEN.GETXML to produce XML from a dynamically created SQL statement, and then uses XML table processing to extract the value.
This is the simplest way to run dynamic SQL in SQL, and it only requires built-in packages. The main limitation is that the number and type of columns is still fixed. If you need a function that returns an unknown number of columns you'll need something more powerful, like the open source program Method4. But that level of dynamic code gets even more difficult and should only be used after careful consideration.
Sample schema
--drop table table1;
create table table1(a number, b number);
insert into table1 values(1, 2);
commit;
Function that returns column name
create or replace function get_col_name(input1 number, input2 number) return varchar2 is
begin
if input1 = 0 then
return 'a';
else
return 'b';
end if;
end;
/
Sample query and result
select dynamic_column
from
(
select xmltype(dbms_xmlgen.getxml('
select '||get_col_name(0,0)||' dynamic_column from table1'
)) xml_results
from dual
)
cross join
xmltable
(
'/ROWSET/ROW'
passing xml_results
columns dynamic_column varchar2(4000) path 'DYNAMIC_COLUMN'
);
DYNAMIC_COLUMN
--------------
1
If you change the inputs to the function the new value is 2 from column B. Use this SQL Fiddle to test the code.
I am new to Oracle. I have a table in Oracle which has 4 columns Period, Open_Flag,Creation_Dt,Updated_By.
The Period column is the Primary key of the table. I have created a proc which will check the value of period from input parameter in the table, if its existing, the value of Open_flag has to be updated else a new record shall be inserted.
create or replace
PROCEDURE PROC_REF_SAP_PERIOD(
V_PERIOD IN NUMBER,V_OPEN_FLAG IN VARCHAR2,V_CREATION_DT IN DATE,V_UPDATED_BY IN VARCHAR2)
AS
BEGIN
MERGE INTO REF_SAP_PERIOD T
USING (SELECT * FROM REF_SAP_PERIOD WHERE PERIOD=V_PERIOD )S
ON (T.PERIOD=S.PERIOD )
WHEN MATCHED THEN UPDATE SET OPEN_FLAG = V_OPEN_FLAG --WHERE PERIOD=V_PERIOD AND CREATION_DT=V_CREATION_DT AND UPDATED_BY=V_UPDATED_BY
WHEN NOT MATCHED THEN INSERT (PERIOD,OPEN_FLAG,CREATION_DT,UPDATED_BY) VALUES (V_PERIOD,V_OPEN_FLAG,V_CREATION_DT,V_UPDATED_BY);
END;
The issue is that the Update is working well in this case, however, the insert is not working. Please help.
You are merging table with itself, filtered by period. Obviously, it will never see your non-existent values in itself.
Try this line instead of your USING line:
using (select V_PERIOD "period" from dual)S
Oracle 12 introduced nice feature (which should have been there long ago btw!) - identity columns. So here's a script:
CREATE TABLE test (
a INTEGER GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
b VARCHAR2(10)
);
-- Ok
INSERT INTO test (b) VALUES ('x');
-- Ok
INSERT INTO test (b)
SELECT 'y' FROM dual;
-- Fails
INSERT INTO test (b)
SELECT 'z' FROM dual UNION ALL SELECT 'zz' FROM DUAL;
First two inserts run without issues providing values for 'a' of 1 and 2. But the third one fails with ORA-01400: cannot insert NULL into ("DEV"."TEST"."A"). Why did this happen? A bug? Nothing like this is mentioned in the documentation part about identity column restrictions. Or am I just doing something wrong?
I believe the below query works, i havent tested!
INSERT INTO Test (b)
SELECT * FROM
(
SELECT 'z' FROM dual
UNION ALL
SELECT 'zz' FROM dual
);
Not sure, if it helps you any way.
For, GENERATED ALWAYS AS IDENTITY Oracle internally uses a Sequence only. And the options on general Sequence applies on this as well.
NEXTVAL is used to fetch the next available sequence, and obviously it is a pseudocolumn.
The below is from Oracle
You cannot use CURRVAL and NEXTVAL in the following constructs:
A subquery in a DELETE, SELECT, or UPDATE statement
A query of a view or of a materialized view
A SELECT statement with the DISTINCT operator
A SELECT statement with a GROUP BY clause or ORDER BY clause
A SELECT statement that is combined with another SELECT statement with the UNION, INTERSECT, or MINUS set operator
The WHERE clause of a SELECT statement
DEFAULT value of a column in a CREATE TABLE or ALTER TABLE statement
The condition of a CHECK constraint
The subquery and SET operations rule above should answer your Question.
And for the reason for NULL, when pseudocolumn(eg. NEXTVAL) is used with a SET operation or any other rules mentioned above, the output is NULL, as Oracle couldnt extract them in effect with combining multiple selects.
Let us see the below query,
select rownum from dual
union all
select rownum from dual
the result is
ROWNUM
1
1
Hi actually m trying to insert the bulk records into the DB.
Records are more than the 20000.
I have to insert the records into three tables since these records are corelated.
For example :
1. One sort of data into the Table 1.
1.1 another sort of data into the Table 2.
1.1.1 another sort of data into the Table 3.
we can consider the above statement as nested lenter code hereoop.
Currently m using the Cursor for above approach but it is taking v v v v long time.
waiting for ur valuable suggestion....
It sounds like you want an INSERT ALL statement. Something like
INSERT ALL
WHEN (<<some condition>>) THEN
INTO table1( <<list of columns>> )
VALUES( <<list of columns>> )
WHEN (<<another condition>>) THEN
INTO table2( <<list of columns>> )
VALUES( <<list of columns>> )
WHEN (<<third condition>>) THEN
INTO table3( <<list of columns>> )
VALUES( <<list of columns>> )
SELECT <<list of columns>>
FROM <<source tables>>
WHERE <<some predicates>>
The SELECT statement at the end would generally be whatever query you're using to populate the cursor. The conditions would implement whatever logic you implement inside the loop to determine which table to insert the data into.
If you know that a row from the cursor will always be inserted into a single table, you could use an INSERT FIRST rather than an INSERT ALL (the rest of the syntax remains the same) so that Oracle can stop evaluating conditions once the first condition evaluates to TRUE.
I have an application that uses the Oracle MERGE INTO... DML statement to update table A to correspond with some of the changes in another table B (table A is a summary of selected parts of table B along with some other info). In a typical merge operation, 5-6 rows (out of 10's of thousands) might be inserted in table B and 2-3 rows updated.
It turns out that the application is to be deployed in an environment that has a security policy on the target tables. The MERGE INTO... statement can't be used with these tables (ORA-28132: Merge into syntax does not support security policies)
So we have to change the MERGE INTO... logic to use regular inserts and updates instead. Is this a problem anyone else has run into? Is there a best-practice pattern for converting the WHEN MATCHED/WHEN NOT MATCHED logic in the merge statement into INSERT and UPDATE statements? The merge is within a stored procedure, so it's fine for the solution to use PL/SQL in addition to the DML if that is required.
Another way to do this (other than Merge) would be using two sql statements one for insert and one for update. The "WHEN MATCHED" and "WHEN NOT MATCHED" can be handled using joins or "in" Clause.
If you decide to take the below approach, it is better to run the update first (sine it only runs for the matching records) and then insert the non-Matching records. The Data sets would be the same either way, it just updates less number of records with the order below.
Also, Similar to the Merge, this update statement updates the Name Column even if the names in Source and Target match. If you dont want that, add that condition to the where as well.
create table src_table(
id number primary key,
name varchar2(20) not null
);
create table tgt_table(
id number primary key,
name varchar2(20) not null
);
insert into src_table values (1, 'abc');
insert into src_table values (2, 'def');
insert into src_table values (3, 'ghi');
insert into tgt_table values (1, 'abc');
insert into tgt_table values (2,'xyz');
SQL> select * from Src_Table;
ID NAME
---------- --------------------
1 abc
2 def
3 ghi
SQL> select * from Tgt_Table;
ID NAME
---------- --------------------
2 xyz
1 abc
Update tgt_Table tgt
set Tgt.Name =
(select Src.Name
from Src_Table Src
where Src.id = Tgt.id
);
2 rows updated. --Notice that ID 1 is updated even though value did not change
select * from Tgt_Table;
ID NAME
----- --------------------
2 def
1 abc
insert into tgt_Table
select src.*
from Src_Table src,
tgt_Table tgt
where src.id = tgt.id(+)
and tgt.id is null;
1 row created.
SQL> select * from tgt_Table;
ID NAME
---------- --------------------
2 def
1 abc
3 ghi
commit;
There could be better ways to do this, but this seems simple and SQL-oriented. If the Data set is Large, then a PL/SQL solution won't be as performant.
There are at least two options I can think of aside from digging into the security policy, which I don't know much about.
Process the records to merge row by row. Attempt to do the update, if it fails to update then insert, or vise versa, depending on whether you expect most records to need updating or inserting (ie optimize for the most common case that will reduce the number of SQL statements fired), eg:
begin
for row in (select ... from source_table) loop
update table_to_be_merged
if sql%rowcount = 0 then -- no row matched, so need to insert
insert ...
end if;
end loop;
end;
Another option may be to bulk collect the records you want to merge into an array, and then attempted to bulk insert them, catching all the primary key exceptions (I cannot recall the syntax for this right now, but you can get a bulk insert to place all the rows that fail to insert into another array and then process them).
Logically a merge statement has to check for the presence of each records behind the scenes anyway, and I think it is processed quite similarly to the code I posted above. However, merge will always be more efficient than coding it in PLSQL as it will be only 1 SQL call instead of many.