Dynamic SQL : passing table name as parameter

Question

Hi
I have a SQL query (a store procedure )  that i want to convert to PLSQL
This is a part of my SQL query that i am trying to to find a solution for it, because i cant convert it to oracle :
DECLARE lookupTableRow CURSOR FOR
  SELECT TableName FROM SYS_LookUpTable
  OPEN lookupTableRow
  FETCH NEXT FROM lookupTableRow INTO @tableName
  WHILE @@FETCH_STATUS=0
  BEGIN
  SET @sql='SELECT * FROM '+@tableName
EXECUTE sp_executesql @sql
  IF @counter=0
  BEGIN
  INSERT INTO T_TABLE_MAPPING VALUES('P_MAIN_METADATA', 'Table', @tableName)
  END
  ELSE
  BEGIN
  INSERT INTO T_TABLE_MAPPING VALUES('P_MAIN_METADATA', 'Table'+CONVERT(NVARCHAR(10),@counter), @tableName)
  END
  SET @counter=@counter+1
  FETCH NEXT FROM lookupTableRow INTO @tableName
  END
  CLOSE lookupTableRow
  DEALLOCATE lookupTableRow
As i understand i can't use ORACLE dynamic sql (execute immediate) when the table name is a parameter
Furthermore when i execute this dynamic query in my SQL store procedure each SELECT statement return me as a result the relevant table rows , those result are different in each loop .
So i cant do this too with ORACLE dynamic sql .
Please advice for any solution
* how can i use dynamic sql with table name as parameter ?
* how can i use a "dynamic" cursor, in order to be able to display the dynamic results ?
Thanks for the advice

Answer 1

Hi,
b003cf5e-e55d-4ff1-bdd2-f088a662d9f7 wrote:
Hi
I have a SQL query (a store procedure )  that i want to convert to PLSQL
This is a part of my SQL query that i am trying to to find a solution for it, because i cant convert it to oracle :
DECLARE lookupTableRow CURSOR FOR
  SELECT TableName FROM SYS_LookUpTable
  OPEN lookupTableRow
  FETCH NEXT FROM lookupTableRow INTO @tableName
  WHILE @@FETCH_STATUS=0
  BEGIN
  SET @sql='SELECT * FROM '+@tableName
EXECUTE sp_executesql @sql
  IF @counter=0
  BEGIN
  INSERT INTO T_TABLE_MAPPING VALUES('P_MAIN_METADATA', 'Table', @tableName)
  END
  ELSE
  BEGIN
  INSERT INTO T_TABLE_MAPPING VALUES('P_MAIN_METADATA', 'Table'+CONVERT(NVARCHAR(10),@counter), @tableName)
  END
  SET @counter=@counter+1
  FETCH NEXT FROM lookupTableRow INTO @tableName
  END
  CLOSE lookupTableRow
  DEALLOCATE lookupTableRow
As i understand i can't use ORACLE dynamic sql (execute immediate) when the table name is a parameter
Furthermore when i execute this dynamic query in my SQL store procedure each SELECT statement return me as a result the relevant table rows , those result are different in each loop .
So i cant do this too with ORACLE dynamic sql .
Please advice for any solution
* how can i use dynamic sql with table name as parameter ?
* how can i use a "dynamic" cursor, in order to be able to display the dynamic results ?
Thanks for the advice
I have a SQL query (a store procedure )  that i want to convert to PLSQL
I doesn't help when you use one term to mean another thing.
SQL is a language used in both Oracle and other products, such as Microsoft's SQL Server. I don't know much about SQL Server, but Oracle (at least) doesn't support stored procedures in SQL itself; they have to be coded in some other language, such as PL/SQL.  
As i understand i can't use ORACLE dynamic sql (execute immediate) when the table name is a parameter
If the table name is a parameter (or only known at run-time for any reason), that's exactly the kind of situation where you MUST use dynamic SQL.
The number of columns that a query produces (and their datatypes) is fixed when you compile a query, whether that query is dynamic or not.  If you have multiple queries, that produce result sets with different numbers of columns, then you can't combine them into a single query.  The best you can do with one query is to add NULL columns to some of the queries so they all produce the same number of columns.
If you're just displaying the results, there might not be any reason to combine separate result sets.  Just display one result set after another.
Whenever you have a question, post a little sample data (CREATE TABLE and INSERT statements, relevant columns only) for all the tables involved, and the results you want from that data.
Explain, using specific examples, how you get those results from that data.
Always say what version of Oracle you're using (e.g. 11.2.0.2.0).
See the forum FAQ: https://forums.oracle.com/message/9362002