以下的文章主要是对Oracle合并函数的两种类型的介绍，即，Oracle9i与Oracle10g相关实际应用代码的介绍，以及Oracle9i的具体使用方案的描述，下面就是文章的具体内容的介绍，望你会有所收获。

Oracle合并函数之9i下：

createtypestrcat_typeasobject( 
cat_stringvarchar2(4000), 
staticfunctionODCIAggregateInitialize(cs_ctxInOutstrcat_type)returnnumber, 
memberfunctionODCIAggregateIterate(selfInOutstrcat_type,valueinvarchar2)returnnumber, 
memberfunctionODCIAggregateMerge(selfInOutstrcat_type,ctx2InOutstrcat_type)returnnumber, 
memberfunctionODCIAggregateTerminate(selfInOutstrcat_type,returnValueOutvarchar2,flagsinnumber)returnnumber 
) 
/ 
createtypebodystrcat_typeis 
staticfunctionODCIAggregateInitialize(cs_ctxINOUTstrcat_type)returnnumber 
is 
begin 
cs_ctx:=strcat_type(null); 
returnODCIConst.Success; 
end; 
memberfunctionODCIAggregateIterate(selfINOUTstrcat_type, 
valueINvarchar2) 
returnnumber 
is 
begin 
self.cat_string:=self.cat_string||','||value; 
returnODCIConst.Success; 
end; 
memberfunctionODCIAggregateTerminate(selfINOutstrcat_type, 
returnValueOUTvarchar2, 
flagsINnumber) 
returnnumber 
is 
begin 
returnValue:=ltrim(rtrim(self.cat_string,','),','); 
returnODCIConst.Success; 
end; 
memberfunctionODCIAggregateMerge(selfINOUTstrcat_type, 
ctx2INOutstrcat_type) 
returnnumber 
is 
begin 
self.cat_string:=self.cat_string||','||ctx2.cat_string; 
returnODCIConst.Success; 
end; 
end; 
/ 
CREATEorreplace 
FUNCTIONstrcat(inputvarchar2) 
RETURNvarchar2 
PARALLEL_ENABLEAGGREGATEUSINGstrcat_type; 
/ 

使用方法：

selectt2.kdm_mdid_pk,t2.kdm_title, 
strcat(t3.subject_mc_content)message 
fromt_knodoc_rel_subjectst1, 
T_KNO_DOC_METADATAt2, 
T_SUBJECT_MULTILINGUAL_CONTENTt3 
wheret1.krs_kdm_mdid_fk=t2.kdm_mdid_pk 
andt1.krs_subid_fk=t3.subject_mc_id_pk 
groupbyt2.kdm_mdid_pk,t2.kdm_title 

Oracle合并函数之10g下：

selectt2.kdm_mdid_pk,t2.kdm_title,WMSYS.WM_CONCAT(t3.subject_mc_content)message 
fromt_knodoc_rel_subjectst1, 
T_KNO_DOC_METADATAt2, 
T_SUBJECT_MULTILINGUAL_CONTENTt3 
wheret1.krs_kdm_mdid_fk=t2.kdm_mdid_pk 
andt1.krs_subid_fk=t3.subject_mc_id_pk 
groupbyt2.kdm_mdid_pk,t2.kdm_title