如何在 SAP HANA 的动态 sql 中使用表变量？

Question

Inside a procedure, I use a table variable to store the some result from table A.

I have to use this table variable in dynamic sql.

Eg)

Call Procedure A()

Begin

VAR_TAB = select customer_id from table_A;

EXEC ' select * from'||: var_tab;

End;

The above code will throw error. Anyone has a solution for this?

Answer 1

Depends on your use case:

You can use the table variable like a temporary table and can use it w/o dynamic sql:

CREATE PROCEDURE c AS 
BEGIN
    var_tab = SELECT customer_id FROM table_A ;
    select * from :var_tab;
END;

If the result contains the actual table name, you have to use dynamic SQL and can access the table variable value as array :

CREATE PROCEDURE b AS 
BEGIN
    var_tab = SELECT customer_id FROM table_A ;
    EXECUTE IMMEDIATE ' select * from '||:var_tab.customer_id[1];
END;

or use a scalar variable :

CREATE PROCEDURE a AS 
BEGIN
    DECLARE var_tab nvarchar(20);
    SELECT customer_id INTO var_tab FROM table_A ;
    EXECUTE IMMEDIATE ' select * from '||var_tab;
END;