Select schema via cursor

Question

I am working with a database in which all schemas have the same tables. I am trying to write a PL/SQL routine that will loop through each schema, query a table in that schema, and insert that data into a master table (simplified explanation). I can get a cursor that contains all the schemas, but I can't figure out how to set the schema name from a cursor.
sample code ... (not working)
declare
cursor schemaCrsr is select SCHEMA_NAME from MASTER.SCHEMA_TABLE;
begin
for mySchemaCrsr in schemaCrsr loop
insert into MASTER.TABLE_X
select * from mySchemaCrsr.TABLE_X;
end loop;
end;
What is the correct syntax for "mySchemaCrsr.TABLE_X" to enable this? Or is there another way to accomplish this?
Thanks

Answer 1

Chris,
I'm using Oracle version 8.1.6 now, so I can't tell if this will work in Oracle version 7.3.4 or not, but I think I remember using something similar in Oracle version 8.0.5. Please try the code below and let us know if it works for you or not.
Also, posting on this forum causes spaces to be added between concatenation symbols where they don't belong, so anywhere you see a space between | and |, remove the space, before running the code.
Any time that you are using some sort of variable to represent a schema name or table name or column name at run time, you have to use some sort of dynamic sql. Execute immediate is a new type of dynamic sql. DBMS_SQL is an older method.
Barbara
DECLARE
CURSOR schemacrsr
IS
SELECT schema_name
FROM master.schema_table;
cursor_name INTEGER;
rows_inserted INTEGER;
BEGIN
FOR myschemacrsr IN schemacrsr
LOOP
cursor_name := DBMS_SQL.OPEN_CURSOR;
DBMS_SQL.PARSE
(cursor_name,
'INSERT INTO master.table_x SELECT * FROM '
| | myschemacrsr.schema_name
| | '.table_x',
DBMS_SQL.NATIVE);
rows_inserted := DBMS_SQL.EXECUTE (cursor_name);
DBMS_SQL.CLOSE_CURSOR (cursor_name);
END LOOP;
END;
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