In Oracle, I would sometimes like to create constructs such as these ones
SELECT * FROM TABLE(STRINGS('a', 'b', 'c'))
SELECT * FROM TABLE(NUMBERS(1, 2, 3))
Obviously, I can declare my own types for the above. I can choose between TABLE
and VARRAY
. For example:
CREATE TYPE STRINGS AS TABLE OF VARCHAR2(100);
CREATE TYPE NUMBERS AS VARRAY(100) OF NUMBER(10);
In this particular case, another solution is to write things like
SELECT 'a' FROM DUAL UNION ALL
SELECT 'b' FROM DUAL UNION ALL
SELECT 'c' FROM DUAL
But I may have more complex examples where I will really need a TABLE
/ VARRAY
type. So what if my SQL is running on an unknown system where I cannot create types because I may not have the necessary grants?
So my question is: Does Oracle know "anonymous" TABLE
/ VARRAY
types that are available on any Oracle instance? Similar to Postgres / H2 / HSQLDB's simple ARRAY
types?
UPDATE: I am mostly running this SQL from Java, if this is relevant. No need to explain PL/SQL to me, I'm really just looking for anonymous SQL array types (i.e. "anonymous" standalone stored types). If they don't exist at all, the answer is NO
Differences Between Varrays And Nested TablesA Varray which is stored in a database maintains its subscripts and sequence. It is always maintained as a single object. Whereas, the nested tables are used when the count of the number of elements is not restricted.
VARRAY stands for the variable-sized array. A VARRAY is single-dimensional collections of elements with the same data type. Unlike an associative array and nested table, a VARRAY always has a fixed number of elements(bounded) and never has gaps between the elements (not sparse).
The most common type of table in an Oracle database is a relational table, which is structured with simple columns similar to the employees table. Two other table types are supported: object tables and XMLType tables. Any of the three table types can be defined as permanent or temporary.
RECORD and TABLE are user-defined composite types that can be defined by the programmer. The record type allows the defination of a type that consists of specified fields. Once the type has been defined, you can then define a specific name for the type as it is being used, a variable name that references the type.
Providing you're not scared of explicitly referencing the SYS schema there are a few. Here are some I use quite often (well odcivarchar2list
not so much, as it chews up a lot of memory: for strings I prefer dbms_debug_vc2coll
).
SQL> desc sys.odcinumberlist
sys.odcinumberlist VARRAY(32767) OF NUMBER
SQL> desc sys.odcivarchar2list
sys.odcivarchar2list VARRAY(32767) OF VARCHAR2(4000)
SQL> desc sys.ODCIDATELIST
sys.ODCIDATELIST VARRAY(32767) OF DATE
SQL> desc sys.dbms_debug_vc2coll
sys.dbms_debug_vc2coll TABLE OF VARCHAR2(1000)
SQL>
However, if those aren't sufficient for your needs run this query to find some more:
select type_name
, owner
from all_types
where typecode = 'COLLECTION'
and owner != user
/
Of course, this result will vary from database to database. For instance a lot of the colllections on my database are owned by XDB and not every system will have that installed. The four I listed at the the top of this answer should be available on every database since 9iR2 (and perhaps early) although they are not always documented in earlier versions.
"Note that ALL_COLL_TYPES seems to be an even better dictionary view to find appropriate types"
That's a good point. We can also filter on COLL_TYPE to winnow out the VARRAYs. That view was introduced into 10g whereas ALL_TYPES was available on 9i. As with most things Oracle, the later the version the more functionality it has.
An interesting solution was given by user APC here. For future readers of this question, it may be interesting to see that this query provides what I'm really interested in:
select coll_type, elem_type_name, type_name, length, upper_bound
from all_coll_types
where owner = 'SYS'
and elem_type_name IN ('VARCHAR2', 'NUMBER')
order by coll_type, elem_type_name, type_name;
Resulting in (in Oracle 11g):
+-------------+--------------+----------------------+------+-----------+
|COLL_TYPE |ELEM_TYPE_NAME|TYPE_NAME |LENGTH|UPPER_BOUND|
+-------------+--------------+----------------------+------+-----------+
|TABLE |NUMBER |KU$_OBJNUMSET |{null}| {null}|
|TABLE |NUMBER |KU$_XMLCOLSET_T |{null}| {null}|
|TABLE |NUMBER |ORA_MINING_NUMBER_NT |{null}| {null}|
|TABLE |VARCHAR2 |DBMS_AW$_COLUMNLIST_T | 100| {null}|
|TABLE |VARCHAR2 |DBMS_DEBUG_VC2COLL | 1000| {null}|
|TABLE |VARCHAR2 |HSBLKNAMLST | 30| {null}|
|TABLE |VARCHAR2 |KU$_VCNT | 4000| {null}|
|TABLE |VARCHAR2 |ORA_MINING_VARCHAR2_NT| 4000| {null}|
|VARYING ARRAY|NUMBER |AWRRPT_NUM_ARY |{null}| 30|
|VARYING ARRAY|NUMBER |JDM_NUM_VALS |{null}| 999|
|VARYING ARRAY|NUMBER |ODCIGRANULELIST |{null}| 65535|
|VARYING ARRAY|NUMBER |ODCINUMBERLIST |{null}| 32767|
|VARYING ARRAY|NUMBER |SQL_OBJECTS |{null}| 2000|
|VARYING ARRAY|NUMBER |TABLESPACE_LIST |{null}| 64000|
|VARYING ARRAY|VARCHAR2 |AQ$_JMS_NAMEARRAY | 200| 1024|
|VARYING ARRAY|VARCHAR2 |AQ$_MIDARRAY | 32| 1024|
|VARYING ARRAY|VARCHAR2 |AWRRPT_VCH_ARY | 80| 30|
|VARYING ARRAY|VARCHAR2 |DBMSOUTPUT_LINESARRAY | 32767| 2147483647|
|VARYING ARRAY|VARCHAR2 |DBMS_XS_ROLELIST | 1024| 4096|
|VARYING ARRAY|VARCHAR2 |FLASHBACKTBLIST | 30| 100|
|VARYING ARRAY|VARCHAR2 |HSBLKVALARY | 4000| 250|
|VARYING ARRAY|VARCHAR2 |JDM_ATTR_NAMES | 60| 999|
|VARYING ARRAY|VARCHAR2 |JDM_STR_VALS | 4000| 999|
|VARYING ARRAY|VARCHAR2 |KU$_DROPCOLLIST | 4000| 1000|
|VARYING ARRAY|VARCHAR2 |KUPC$_LOBPIECES | 4000| 4000|
|VARYING ARRAY|VARCHAR2 |ODCIRIDLIST | 5072| 32767|
|VARYING ARRAY|VARCHAR2 |ODCIVARCHAR2LIST | 4000| 32767|
|VARYING ARRAY|VARCHAR2 |RE$NAME_ARRAY | 30| 1024|
|VARYING ARRAY|VARCHAR2 |RE$RULE_LIST | 65| 1024|
|VARYING ARRAY|VARCHAR2 |SQLPROF_ATTR | 500| 2000|
|VARYING ARRAY|VARCHAR2 |TXNAME_ARRAY | 256| 100|
+-------------+--------------+----------------------+------+-----------+
It looks as though ORA_MINING_NUMBER_NT
and ORA_MINING_VARCHAR2_NT
will be the best match for my needs.
If using Oracle 12c and PL/SQL, there's also the possibility to use any of the DBMS_SQL
types, which can be unnested using the TABLE(..)
constructor. There are:
DBMS_SQL.CLOB_TABLE
DBMS_SQL.BINARY_FLOAT_TABLE
DBMS_SQL.BINARY_DOUBLE_TABLE
DBMS_SQL.BLOB_TABLE
DBMS_SQL.BFILE_TABLE
DBMS_SQL.DATE_TABLE
DBMS_SQL.NUMBER_TABLE
DBMS_SQL.UROWID_TABLE
DBMS_SQL.VARCHAR2_TABLE
DBMS_SQL.TIME_TABLE
DBMS_SQL.TIME_WITH_TIME_ZONE_TABLE
DBMS_SQL.TIMESTAMP_TABLE
DBMS_SQL.TIMESTAMP_WITH_LTZ_TABLE
DBMS_SQL.TIMESTAMP_WITH_TIME_ZONE_TABLE
DBMS_SQL.INTERVAL_DAY_TO_SECOND_TABLE
DBMS_SQL.INTERVAL_YEAR_TO_MONTH_TABLE
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