string-aggregation

This question already has an answer here: How can I combine multiple rows into a comma-delimited list in Oracle? [duplicate] 11 answers I have a table named "person". It contains person's id and it's parent id (only one parent is possible). As a result of a query, I want a table with first column - a person id, and a second column - a list of it's children id's. How exactly to do this? I've read about listagg function, but I'm not sure if it is appropriate for my purpose. And this query produces an empty second column: select t1.id, (select t2.id from person t2 where t2.parent_id = t1.id) from

My table structure look like this, I am new for the this field. I know the basic queries.But it's complicated for me. Please help me to do this. Table structure Customer Product piriority 10001 Main_product 1 10001 Sub_product1 2 10001 Sub_product2 2 10001 Sub_product3 2 10001 Sub_product4 2 10002 Main_product 1 10002 Sub_product1 2 10002 Sub_product2 2 Expected Output: Customer Main_Product Sub_product 10001 Main_product Sub_product1,Sub_product2,Sub_product3,Sub_product4 10002 Main_product Sub_product1,Sub_product2 I'm going to assume that the PRIORITY column is always 1 when there's a "main

I have this query : (SELECT OBJECT_ID from cr_object_group_entries_vw where object_group_id IN (SELECT ITEM FROM TABLE(CR_FN_SPLIT_STRING('28,56',',')))) that returns : But when I do : SELECT wm_concat(object_id) FROM (SELECT OBJECT_ID from cr_object_group_entries_vw where object_group_id IN (SELECT ITEM FROM TABLE(CR_FN_SPLIT_STRING('28,56',',')))) I get a blank result... what am I doing wrong? You must avoid wm_concat function because it is undocumented and discovered as workaround at Oracle 8i times. Since times of old method with custom aggregate function as discovered by Tom Kyte here

This question already has an answer here: How can I combine multiple rows into a comma-delimited list in Oracle? [duplicate] 11 answers I'm trying to convert a single-columned subquery into a command-separated VARCHAR -typed list of values. This is identical to this question , but for Oracle rather than SQL Server or MySQL. There is an excellent summary of the available string aggregation techniques on Tim Hall's site. I found this that seems to work. Thoughts? SELECT SUBSTR (c, 2) concatenated FROM (SELECT SYS_CONNECT_BY_PATH ( myfield, ',') c, r FROM (SELECT ROWNUM ID, myfield, RANK () OVER

This question already has an answer here: SQL Query to concatenate column values from multiple rows in Oracle 11 answers How can I achieve the following in oracle without creating a stored procedure? Data Set: question_id element_id 1 7 1 8 2 9 3 10 3 11 3 12 Desired Result: question_id element_id 1 7,8 2 9 3 10,11,12 There are many way to do the string aggregation, but the easiest is a user defined function. Try this for a way that does not require a function. As a note, there is no simple way without the function. This is the shortest route without a custom function: (it uses the ROW_NUMBER(