alternative to listagg in Oracle?

Question

listagg is a function introduced in Oracle 11.2! now this function is bugging us allot, we are migrating from MySQL to Oracle and we have this query:

SELECT
         


        

Answer 1

You can solve the ORA-22814 error by using MULTISET instead of COLLECT:

SELECT
    p_id,
    MAX(registered) AS registered,
    listaggclob(cast(multiset(
        select MESSAGE
        from umm_parent_id_remarks_v
        where umm_parent_id_remarks_v.p_id = m.p_id
    ) as clob_t)) MESSAGE
  FROM
    umm_parent_id_remarks_v m
  GROUP BY
    m.p_id;

Answer 2

Use collect or write your own aggregation function.

Answer 3

WM_CONCAT worked for me.

SELECT replace(WMSYS.WM_CONCAT(myTable.name), ',', ';')
FROM myTable
GROUP BY myTable.id

I wrapped it with a "replace" to specify a different item separator (';') from the one used by WM_CONCAT (',').

Answer 4

You might want to look at user-defined aggregate functions.

Differnt string aggregation techniques are shown here. They include an example for user-defined aggregate functions.

Answer 5

-- Creating Clobe Type -- CREATE OR REPLACE TYPE "MSCONCATIMPL_CLOB" AS OBJECT ( resultstring CLOB, delimiter VARCHAR2(10),

STATIC FUNCTION odciaggregateinitialize ( io_srccontext IN OUT msconcatimpl_clob ) RETURN NUMBER,

MEMBER FUNCTION odciaggregateiterate (
    self IN OUT msconcatimpl_clob,
    value   IN CLOB
) RETURN NUMBER,

MEMBER FUNCTION odciaggregateterminate (
    self            IN msconcatimpl_clob,
    o_returnvalue   OUT CLOB,
    i_flags         IN NUMBER
) RETURN NUMBER,

MEMBER FUNCTION odciaggregatemerge (
    self IN OUT msconcatimpl_clob,
    i_ctx2   IN msconcatimpl_clob
) RETURN NUMBER

); / -- Creating Clobe Type Body --

CREATE OR REPLACE TYPE BODY "MSCONCATIMPL_CLOB" IS STATIC FUNCTION odciaggregateinitialize ( io_srccontext IN OUT msconcatimpl_clob ) RETURN NUMBER IS BEGIN io_srccontext := msconcatimpl_clob( NULL, NULL ); io_srccontext.delimiter := ' '; RETURN odciconst.success; END odciaggregateinitialize;

MEMBER FUNCTION odciaggregateiterate (
    self IN OUT msconcatimpl_clob,
    value   IN CLOB
) RETURN NUMBER
    IS
BEGIN
    IF
        value IS NOT NULL
    THEN
        IF
            self.resultstring IS NULL
        THEN
            self.resultstring := self.resultstring || value;
        ELSE
            self.resultstring := self.resultstring
             || self.delimiter
             || value;
        END IF;
    END IF;

    RETURN odciconst.success;
END odciaggregateiterate;

MEMBER FUNCTION odciaggregateterminate (
    self            IN msconcatimpl_clob,
    o_returnvalue   OUT CLOB,
    i_flags         IN NUMBER
) RETURN NUMBER
    IS
BEGIN
    o_returnvalue := self.resultstring;
    RETURN odciconst.success;
END odciaggregateterminate;

MEMBER FUNCTION odciaggregatemerge (
    self IN OUT msconcatimpl_clob,
    i_ctx2   IN msconcatimpl_clob
) RETURN NUMBER
    IS
BEGIN
    IF
            self.resultstring IS NULL
        AND
            i_ctx2.resultstring IS NOT NULL
    THEN
        self.resultstring := i_ctx2.resultstring;
    ELSIF
        self.resultstring IS NOT NULL
    AND
        i_ctx2.resultstring IS NOT NULL
    THEN
        self.resultstring := self.resultstring
         || self.delimiter
         || i_ctx2.resultstring;
    END IF;

    RETURN odciconst.success;
END odciaggregatemerge;

END; /

-- Creating Clobe Function --

CREATE OR REPLACE FUNCTION ms_concat_clob ( input VARCHAR2 ) RETURN CLOB PARALLEL_ENABLE AGGREGATE USING msconcatimpl_clob; /

Answer 6

Use xmlAgg, example is shown below:

SELECT RTRIM(XMLAGG(XMLELEMENT(E,colname,',').EXTRACT('//text()') ORDER BY colname).GetClobVal(),',') AS LIST
FROM tablename;

This will return clob value and so no need to create custom function.