While循环用于选择字段名称？

Question

I have a nasty, nasty data layout that I am forced to work with. I finally got a working query using C# and a for loop executing the same query over and over but adjusting which fields are called, but now I am wondering if it is possible to do it with a while loop. I am getting an error, and I am not sure if it is because I am using Faircom / C-tree as the database, or if there is something wrong with my query. I am normally a Mysql user.

the table has 20 fields I care about and want to extract into a csv list. They are codetype1-codetype20 and I want it to be something like value1, value2, value3... where as it is now I get them all back one at a time. Trouble is that codetype1 is dependent on another field to determine where I go look for the info on that code, which is why the case statements.

DROP PROCEDURE IF EXISTS proc_loop_test;
CREATE PROCEDURE proc_loop_test()
    SET @index = 1;
    WHILE(@index  < 21) DO

        SELECT Replace(Concat(To_char(apptid), To_char(.@index) ), ' ', '') AS reference_id,
                   apptid                                                              AS a_reference_id,
                   CASE
                     WHEN c.ee > 0 THEN d.amt
                     ELSE insfee.amt
                   END                                                    AS amount,
                   CASE
                     WHEN c.ee > 0 THEN Rtrim(e.moneyname)
                     ELSE insname.namefeecatid
                   END                                                    AS moneyschedule_name,
                   CASE codetype@index
                              WHEN 1 THEN rtrim(a.descript)
                              ELSE rtrim(b.descript0)
                   END                                                                  AS description,
                   CASE codetype@index
                              WHEN 1 THEN rtrim(a.abbrevdescript)
                              ELSE rtrim(b.abbrev0)
                   END                                                                  AS abbreviated_description,
                   CASE codetype@index
                              WHEN 1 THEN rtrim(a.thiscode)
                              ELSE rtrim(b.thiscode0)
                   END AS code
        FROM       meetings
        LEFT JOIN
                   (
                        SELECT     admin.table2.procid,
                                    admin.table2.this_code_id,
                                    admin.v_table1.descript,
                                    admin.v_table1.abbrevdescript,
                                    admin.v_table1.thiscode
                        FROM       admin.table2
                        INNER JOIN admin.v_table1
                        ON         admin.table2.this_code_id = admin.v_table1.this_code_id) AS a
        ON         meetings.codeid@index = a.procid
        LEFT JOIN
                   (
                          SELECT admin.v_table1.descript       AS descript0,
                                 admin.v_table1.abbrevdescript AS abbrev0,
                                 admin.v_table1.thiscode        AS thiscode0,
                                 admin.v_table1.this_code_id
                          FROM   admin.v_table1) AS b
        ON         meetings.codeid@index = b.this_code_id
        LEFT JOIN
                   (
                          SELECT patid AS id,
                                 ee
                          FROM   admin.customer) AS c
        ON         meetings.patid = c.id
        LEFT JOIN
                   (
                          SELECT this_code_id AS redid,
                                 eecategoryid,
                                 amt
                          FROM   admin.eeule) AS d
        ON         c.ee = d.eecategoryid
        AND        d.redid = b.this_code_id
        LEFT JOIN
                   (
                          SELECT eecategoryid AS namefeecatid,
                                 moneyname
                          FROM   admin.eeulenames) AS e
        ON         d.eecategoryid = e.namefeecatid
        LEFT JOIN (SELECT pi.customer_id,
                            pi.primarykk_id AS picid,
                            pi.primarykk_name,
                            pi.first_name,
                            pi.last_name,
                            i.groupname,
                            i.ee
                    FROM   admin.v_pir AS pi
                            LEFT JOIN admin.money AS i
                                ON pi.primarykk_id = i.insid) AS
                    ins
                ON ins.customer_id = c.id
        LEFT JOIN (SELECT this_code_id AS redid,
                            eecategoryid,
                            amt
                    FROM   admin.eeule) AS insfee
                ON ins.ee = insfee.eecategoryid
                    AND insfee.redid = b.this_code_id
       LEFT JOIN (SELECT eecategoryid AS namefeecatid,
                         moneyname
                  FROM   admin.eeulenames) AS insname
              ON insfee.eecategoryid = insname.namefeecatid
        WHERE      codeid@index >= 1
    END WHILE;
END;

I have never used a while loop, and while I understand somewhat I am supposed to select this to go INTO something, do I need to create a temp table, or can it all just be stored in memory till the end of the loop and returned.

For what it is worth, the entire SELECT query works in C# when you replace the @index with concatenating format " . index . "

Answer 1

Based on the information that you have provided, it is strongly suggested that you reach out to your vendor for this. You're attempting to create a stored procedure, however, using a mySQL proprietary syntax. Stored procedure support is unique to each database vendor. FairCom's c-treeACE SQL actually uses Java for cross platform support and .NET for Windows.

https://docs.faircom.com/doc/jspt/#cover.htm

Stored procedure development requires a strong knowledge of the database layout which is highly application dependent. In this case, many legacy application dependencies may be involved. Again, your best source of information will be your application vendor.