使用游标填充PLSQL DEFINE变量

Question

我需要有关动态SQL和游标的帮助。 我有具有DEFINE变量的存储过程。 如何使用光标填充DEFINE变量？

我想使用另一个表作为游标的源并将这些结果插入另一个表。

这是关于我的问题的简化示例：

CREATE OR REPLACE PROCEDURE usp_TEST
AS
BEGIN

DEFINE vTable = 'TABLE_NAME'; -- How I can create cursor loop, so I can loop and change this table name using another table as source?


INSERT INTO results
WITH CTE_main
AS
(
    SELECT 
        TABLE_NAME 
    FROM dest_TABLES
)
SELECT 
    'SELECT * FROM ' || '&vTable' || ' source INNER JOIN ' ||  cte.TABLE_NAME || ' dest ON source.ID = dest.ID;' AS query 
FROM CTE_main cte

END;

源表仅包含表名：

TABLE_ONE

TABLE_TWO

等等...

结果应该是这样的：

SELECT * FROM TABLE_ONE source INNER JOIN DEST_ONE dest ON source.ID = dest.ID;
SELECT * FROM TABLE_ONE source INNER JOIN DEST_TWO dest ON source.ID = dest.ID;
SELECT * FROM TABLE_TWO source INNER JOIN DEST_ONE dest ON source.ID = dest.ID;
SELECT * FROM TABLE_TWO source INNER JOIN DEST_TWO dest ON source.ID = dest.ID;

Answer 1

您是否喜欢以下内容：

WITH dest_tables AS (SELECT 'TABLE_ONE' table_name FROM dual UNION ALL
                     SELECT 'TABLE_TWO' table_name FROM dual),
        cte_main AS (SELECT 'DEST_ONE' table_name FROM dual UNION ALL
                     SELECT 'DEST_TWO' table_name FROM dual)
SELECT 'SELECT * FROM ' || dt.table_name || ' src INNER JOIN ' ||  cm.TABLE_NAME || ' dest ON src.ID = dest.ID;' AS query 
FROM   dest_tables dt
       CROSS JOIN cte_main cm
ORDER BY dt.table_name, cm.table_name;

QUERY
-------------------------------------------------------------------------
SELECT * FROM TABLE_ONE src INNER JOIN DEST_ONE dest ON src.ID = dest.ID;
SELECT * FROM TABLE_ONE src INNER JOIN DEST_TWO dest ON src.ID = dest.ID;
SELECT * FROM TABLE_TWO src INNER JOIN DEST_ONE dest ON src.ID = dest.ID;
SELECT * FROM TABLE_TWO src INNER JOIN DEST_TWO dest ON src.ID = dest.ID;

？ （注意，我使用了从句中的两个子查询来模拟表中的数据；您不需要这两个子查询，只需使用表即可。）

不需要PL / SQL，仅需要SQL。 不过，您可以采用上述语句，并将其用于PL / SQL程序内的insert语句中。