ForALL construct: Collection range can be initialized to a constant?

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I want to use ForAll construct in procedure:

Existing For loop is:

      max_versions constant number := 100;
      FOR i IN 1 ..max_vers 
        LOOP
           l_sql := 'update test_table set p' || i ||'= NULL WHERE p' ||i||'=0 AND           condition1=' ||n_input1 ||' AND  condition3 = ' || n_condition3;
         EXECUTE immediate l_sql;

           l_sql := 'update test_table set h' || i ||'= NULL WHERE h ||i||'=0 AND                condition1=' ||n_input1 ||' AND  condition3 = ' || n_condition3;
         EXECUTE immediate l_sql;
        END LOOP;

Here max_vers is a constant 100 and p1...p100 and h1...h100 are columns in a table. In above query null is being set if columns' value is 0.

SO is it possible to use ForAll with a constant rather than collection?

I have tried to do below: First, I tried to use direct constant with 'Count' method but since it is a method of collect

PROCEDURE Test
IS 

TYPE MaxVersTab IS TABLE OF number;
maxvers MaxVersTab := 100; 
                             -- Error1
BEGIN

    FORALL i IN 1 .. maxvers .count
    EXECUTE IMMEDIATE -- Error2 and Error3
    'update test_table set p' || i ||'= NULL WHERE p' ||i||'=0 AND condition1=' ||n_input1 || ' AND condition3 =n_input3' USING maxvers(i);

    FORALL i IN 1 ..  maxversions.count
    EXECUTE IMMEDIATE
    'update test_table set p' || i ||'= NULL WHERE p' ||i||'=0 AND condition1=' ||n_input1 || ' AND condition3=n_input3'  USING maxvers(i);

I am getting different errors as below:

  • Error 1) Expression is of wrong type
  • Error 2) Statement ignored
  • Error 3) the declaration of the type of this expression is incomplete or malformed

My question is , can we assign a range to a collection(like 100) to be used in ForAll. Please let me know.

Regards


No, you can't use FORALL here.

The FORALL statement runs one DML statement multiple times, with different values in the VALUES and WHERE clauses.

You deal with different DML statements, not with the only one. Your DML statements are different because you use different columns in it.

If you have one DML statement you can do something like this:

declare
  TYPE MaxVersTab IS TABLE OF number;
  maxvers MaxVersTab; 
  n_input1 varchar2(32767) := 'some_condition_string';
BEGIN
  select level
  bulk collect into maxvers
  from dual
  connect by level <= 5;

  FORALL i IN 1 .. maxvers .count
    EXECUTE IMMEDIATE
      'update test_table set p1 = null WHERE p1=:bind_variable1 AND condition1=:bind_variable2' using maxvers(i), n_input1;
end;

Arrays, sets, lists, and records, You can access each element of a collection variable by its unique index, with this remain consistent and unique if the values of initialization parameters change. A relatively small lookup table, which can be constructed in memory each time associative arrays with the FORALL statement or BULK COLLECT clause. For example, if FORALL uses the range 5..10, so does %BULK_ROWCOUNT. If the FORALL tatement uses the INDICES OF clause to process a sparse collection, %BULK_ROWCOUNT has corresponding sparse subscripts. If the FORALL statement uses the VALUES OF clause to process a subset of elements,


Just to confirm how you can't use forall:

You can't invoke the forall mechanism on its own as a generator:

begin
    forall i in 1..100
        insert into demo(id) values (i);
end;

fails with:

ORA-06550: line 3, column 38:
PLS-00430: FORALL iteration variable I is not allowed in this context
ORA-06550: line 3, column 9:
PLS-00435: DML statement without BULK In-BIND cannot be used inside FORALL

You have to actually use the collection.

To set up a collection of 100 elements, you have to extend it (so it can't be a constant, unless we write a function to initialise it with). The following runs, but it inserts nulls because we didn't generate any values:

declare 
    type number_tt is table of number;
    numbers number_tt := number_tt();
begin
    numbers.extend(100);

    forall i in 1..100
        insert into demo(id) values (numbers(i));
end;

You can populate the collection from a select (or some other approach), but we are now moving away from the idea of a quick way to prime forall with 100 values so that we can use it to execute some task 100 times.

declare 
    type number_tt is table of number;
    numbers number_tt := number_tt();
begin
    select rownum bulk collect into numbers
    from dual connect by rownum <= 100;

    forall i in 1..100
        insert into demo(id) values (numbers(i));
end;

How to populate/instantiate a C# array with a single value?, More formally, we may define an array as a collection of labeled objects of a given type where the label The order of the list elements is specified by construction. All the cells of fixed size arrays are created and initialized immediately, using default initialization Can use dense format B: array(R:range​,T:range) of real ! Associative arrays are appropriate for relatively small lookup tables where the collection can be constructed in memory each time a procedure is called or a package is initialized. They are good for collecting information whose volume is unknown beforehand, because there is no fixed limit on their size.


Instead of using For loop , I am using static query which would update h1..h100 and p1...p100 columns in one go.

l_sql := 'UPDATE sh_rpt_temp_peer_final t SET p1= NULLIF(p1, 0),--...NULLIF(p100,0),
h1= NULLIF(h1, 0)  --...NULLIF(h100,0),
where condition1=' ||n_input1 || ' AND condition3 =n_input3';
EXECUTE immediate l_sql;

This will reduce the number of query execution from 200 to 1

Regards

[PDF] OPL Language Reference Manual, Range(0, 1000). For small array you can use the collection initialization syntax in C# 3: Also, I think you avoid the cost of initializing the array slot to the default value. So, for Length ) ) { throw new ArgumentOutOfRangeException( "count", "​" ); } const int Gap = 16; int i = startIndex; if ( count <= Gap * 2 ) { while ( count > 0 )​  Multiple constants of the same type can be declared at the same time, for example: class Calendar2 { public const int Months = 12, Weeks = 52, Days = 365; } The expression that is used to initialize a constant can refer to another constant if it does not create a circular reference. For example:


Initializing Arrays in Java, Dynamic collection of elements into arrays . Integer ranges are fundamental in OPL, since they are often used in arrays and You can initialize arrays by listing its values, as in most of the These expressions are also used in forall Integer expressions are constructed from integer constants, integer  If you issue the INSERT through the FORALL statement, you can insert values from an entire collection of records. The number of fields in the record must equal the number of columns listed in the INTO clause, and corresponding fields and columns must have compatible data types.


5 Using PL/SQL Collections and Records, Discover different ways of initializing arrays in Java. And let's also see how we can initialize a multi-dimensional array one An attempt to do so will result in a compilation error. The method also has several alternatives which set a range of an Note that this method is overloaded for all primitive types. You can minimize the performance overhead of this communication between PL/SQL and SQL by using the PL/SQL language features known collectively as bulk SQL. The FORALL statement sends INSERT , UPDATE , or DELETE statements in batches, rather than one at a time.


Collection Types, You can define collection types in a procedure, function, or package. when using other types that the values used as keys are consistent and unique. arrays with bulk constructs (the FORALL statement or BULK COLLECT clause). Until you initialize it, a nested table or varray is atomically null; the collection itself is null,  How do you initialize a PL/SQL table of records in the Declaration section of a PL/SQL block? In the following snippet, I can successfully initialize a normal scalar PL/SQL table but am unsuccessful initializing a table of records. Can it be done? Also, why is the last loop bombing with "Reference to uninitialized collection"? SET SERVEROUTPUT ON