How to transform this PL/SQL request into a PL/SQL function ?

Question

Hi nice people !
I have a beautiful flash chart which SQL code is below. I want to display this chart only if this query returns results. I tried to put it as condition. How to transformt this SQL ciode as "SLQ Function returning a boolean" ?
DECLARE
X VARCHAR2 (4000);
BEGIN
x :=
'SELECT NULL LINK, trunc(a.DATE1, '''||:P13_TRUNC||'''), avg(b.pourcentage_remplissage)
FROM    EVV_'||:P13_SITE||' a, bassin_remplissage b
WHERE   a.CLEF_VAR = (SELECT CLEF_VAR FROM SITE_ECHELLE WHERE SITE='''||:P13_SITE||''')
AND     round(a.valeur, 1) = b.cote_ngf
AND     DATE1 BETWEEN
TO_DATE ('''||:P13_DATE_DEBUT||'000000'', ''DD/MM/YYYYHH24MISS'') AND
TO_DATE ('''||:P13_DATE_FIN||'235959'', ''DD/MM/YYYYHH24MISS'')
group by trunc(a.DATE1, '''||:P13_TRUNC||''')
ORDER BY trunc(a.DATE1, '''||:P13_TRUNC||''')';
RETURN (X);
END;Thank you for your kind answers.
Christian

Answer 1

Hello Christian,
>> I don't understand your input
Your error is most likely because the dynamic select statement you are trying to build is not correct. As local variables, like the ‘x’ you are using, are not persistence, it’s probably hard for you to see the final value of x.
You should define an application item, like TEMP1, and use it to hold the generated select statement:
BEGIN
:TEMP1 := 'SELECT COUNT(*) INTO WWV_FLOW.g_id
FROM    EVV_'
      || :p13_site
      || ' a, bassin_remplissage b
WHERE   a.CLEF_VAR = (SELECT CLEF_VAR FROM SITE_ECHELLE WHERE SITE='''
      || :p13_site
      || ''')
AND     round(a.valeur, 1) = b.cote_ngf
AND     DATE1 BETWEEN
TO_DATE ('''
      || :p13_date_debut
      || '000000'', ''DD/MM/YYYYHH24MISS'') AND
TO_DATE ('''
      || :p13_date_fin
      || '235959'', ''DD/MM/YYYYHH24MISS'')
group by trunc(a.DATE1, '''
      || :p13_trunc
      || ''')
ORDER BY trunc(a.DATE1, '''
      || :p13_trunc
      || ''')';
return false;
END;Now the process should be evaluated without errors, and TEMP1 should hold the select statement that produces the error. Now, using the developer toolbar, you can inspect the actual select statement ant analyze its syntax and format.
Once you’ll find the error in the select statement, you can go back to Denes original code proposal.
Regards,
Arie.
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