Oracle non Ansi to Ansi T-SQL - sql

Question

I am a SQL server guy, with limited Oracle coding. I have inherited a bunch of views that I need to convert to ANSI. What I am looking for is someone to educate me, if possible, on a systematic way to do this in steps. I have junior guys that would read and understand TSQL style code, instead of the way it is. I want to take this knowledge, and have them start working on them; there are many. A conversion tool will not work, we don't have time to play with one, no budget to buy it, and our IT department will not let us install anything. (We have to do this manually)
I would like to know the steps (systematic approach) based on interpreting the code, not learn the data or try to understand why the existing code was written the way it was.
For example, are these the steps:
Reorder the tables to match how they are in the where clause.
Separate the lines in the where clause based on their table, so that it is easier to read.
Replace the Oracle join operators with left, right, outer, etc.
Leave the lines with defined values in the where clause, or should I include them with an "AND" in the table join.
This task will be done by junior SQL server guys, so it has to be as simple and straight forward as possible.
FROM WORK MECHANISMS WM,
WT_MANPOWER_RESOURCES WTMR,
LOGICAL_ITEMS LI,
APSWHS.WMX_LOG_REL_ELEM WLRE,
WMECH_DSGN_COMP_ELEMENTS WDCE,
WORK_TASKS WT,
persons_v per,
APSWHS.WMX_WO_WF_STATUS WFA,
RT_DETAILS RTD
WHERE
WFA.WF_SEQ > 639
AND WTMR.WTASK_WMECH_DB_ID = WM.DB_ID
AND WTMR.WTASK_DB_ID = 0
AND WTMR.WTMANPOW_TYPE = ‘LEAD’
AND WT.WMECH_DB_ID = WM.DB_ID
AND WT. DB_ID= 0
AND WFA.WM_DB_ID = WM.DB_ID
AND PER.per_db_id = wm.assigned_to_per_db_id
AND RTD.WMECH_DB_ID = WM.DB_ID
AND WDCE .WMECH_DB_ID = WFA.WM_DB_ID
AND WDCE.LITM_ID = WLRE.LITM_ID
AND WDCE.LITM_ID = LI.ID
AND WDCE.PRIMARY_DCID_FLAG = ‘Y’

Answer 1

I'm assuming that you want to migrate from table lists (join predicates in WHERE clause) to ANSI JOIN syntax. This has nothing to do with T-SQL.
Ideally, you'll take an ERD and check in what order the tables should be listed, visually. I personally find that easier than from mere text. Although, it is possible to do with plain text as well. Here are the steps:
Take the first table and all its non-join predicates:
FROM WORK_MECHANISMS WM
WHERE 1 = 1 -- No predicates on this table
Take the next table that you can join to the first one, and all of its join and non-join predicates
FROM WORK_MECHANISMS WM
JOIN WT_MANPOWER_RESOURCES WTMR
ON WTMR.WTASK_WMECH_DB_ID = WM.DB_ID
WHERE WTMR.WTASK_DB_ID = 0
AND WTRM.WTMANPOW_TYPE = 'LEAD'
And the next table...
Observe that this isn't the next table in your original table list, but another one, i.e. the next one that can be joined to the existing join graph without creating a cartesian product. In particular, I skipped (for now) LOGICAL_ITEMS and APSWHS.WMX_LOG_REL_ELEM and WMECH_DSGN_COMP_ELEMENTS. I will add them to the graph later.
FROM WORK_MECHANISMS WM
JOIN WT_MANPOWER_RESOURCES WTMR
ON WTMR.WTASK_WMECH_DB_ID = WM.DB_ID
JOIN WORK_TASKS WT
ON WT.WMECH_DB_ID = WM.DB_ID
WHERE WTMR.WTASK_DB_ID = 0
AND WTRM.WTMANPOW_TYPE = 'LEAD'
AND WT.DB_ID = 0
And the next table...
You continue adding tables to your new statement, until you've added all tables. If you ever encounter a (+) operator, "just" get the LEFT JOIN semantics right.