I have two parameters X and Y
Rules for these are only one of them can be null. They both can be existing, it's ok but they both can't be null.
I'm using this to check if they exist in database so I can assign one and rest of the SP can continue inserting.
SELECT #Id=id FROM Table WHERE (No = #x) OR (No = #y)
What I want to add is if they are both existing I want the Id to be the Id of #x.
I can't get the Case Statement right in my mind. Normally this is a no brainer but somehow I managed to get stuck.
ISNULL() will take the first non null value it finds.
SELECT #Id=id FROM Table WHERE No = ISNULL(#x, #y)
Related
I am working on a solution that involves merging two queries in Power Query to retrieve a single data table back to Excel. The first query is always populated but the other query comes from an ERP and might be empty (empty table) from time to time.
Appending the two queries involves making the header names the same in the two queries before the appending takes place. As the second query sometimes results in an empty table, the error arises in the steps when Power Query is modifying the header names in the second table (it cannot modify the header names as there are no headers).
"Error message: Expression.Error: The column 'PartMtl_Company' of the table wasn't found.
Details: PartMtl_Company" where the PartMtl_Company is the leftmost column in my table.
I am kind of thinking that I would need to evaluate whether the second table is empty and skip the renaming steps if that is the case. I assume merging the populated first table with an empty table would cause no problem and would only result in the first table. I have tried to look around for a suitable M-code but have not come across such.
I'm thinking you might be able to use Table.RowCount to solve this. Something along the lines of:
= if Table.RowCount(Table2) > 0 then...
You would modify the headers only if there is data in the second table. Same goes for the appending of the tables: you would only append if there is data in the second table, since you won't have renamed any headers otherwise.
Thank you Marc! That did the trick.
In the end, I wrote some in the lines of
= if Table.RowCount(Table2) > 0 then... (code that works on a non-empty table) ...else Table2
, which returns the empty table if it is empty to begin with. Appending the second table into the first table did not throw an error but returned only the first table like planned.
The program just selects everything if the carrid is ok even if it is not ok with the lt_spfli. And there aren't any entries with that carrid it gets runtime error. If I try with for all entries he just selects absolutely the entire SFLIGHT.
PARAMETERS: pa_airp TYPE S_FROMAIRP,
pa_carid TYPE S_CARR_ID.
DATA: lt_spfli TYPE RANGE OF SPFLI,
lt_sflight TYPE TABLE OF SFLIGHT.
SELECT CONNID FROM SPFLI
INTO TABLE lt_spfli
WHERE AIRPFROM = pa_airp.
SELECT * FROM SFLIGHT
INTO TABLE lt_sflight
WHERE CARRID = pa_carid AND CONNID in lt_spfli.
I just suppose, that you want every flight connection from a given airport...
Notice, that a RANGE structure has two more fields in front of the actual "compare value". So selecting directly into it will result in a very gibberish table.
Possible Solutions:
Selecting with RANGE
If you really want to use this temporary table, you can have a look at my answer here where I describe the way to fill RANGEs without any overhead. After this step, your current snippet will work the way to wanted it too. Just make sure, that it really has been filled or everything will be selected.
Selecting with FOR ALL ENTRIES
Before you use this variant you should make absolutely sure, that your specified data object is filled. Otherwise it will result in the same mess as the first solution. To do that, you could write:
* select connid
IF lt_spfli[] IS NOT INITIAL.
* select on SFLIGHT
ELSE.
* no result
ENDIF.
Selecting with JOIN
The "correct" approach in this case would be a JOIN like:
SELECT t~*
FROM spfli AS i
JOIN sflight AS t
ON t~carrid = #pa_carid
AND t~connid = i~connid
INTO TABLE #DATA(li_conns)
WHERE i~airpfrom = #pa_airp.
Use a FOR ALL ENTRIES instead of CONNID in lt_SPFLI.
As so:
SELECT *
FROM sflight
FOR ALL ENTRIES IN lt_spfli
WHERE carrid = pa_carid
AND connid = lt_spfli-connid
You are misunderstanding what a "Ranges Table" is. You fill it incorrectly.
This part of your code demonstrates the misunderstanding (with a little debug, you would see the erroneous contents immediately):
DATA: lt_spfli TYPE RANGE OF SPFLI.
SELECT CONNID FROM SPFLI INTO TABLE lt_spfli ...
A "Ranges Table" is an internal table with 4 components (SIGN, OPTION, LOW, HIGH), used in Open SQL to do complex selections on one database column (NB: it can also be used in several ABAP statements to test the value of an ABAP variable).
So, with your SQL statement, you only initialize the first component of the Ranges table, while you should transfer CONNID into the third component.
In "modern" Open SQL, you'd better do:
SELECT 'I' as SIGN, 'EQ' as OPTION, CONNID as LOW FROM SPFLI INTO TABLE #lt_spfli ...
For more information about Ranges Tables, you may refer to the answer here: What actually high and low means in a ranges table
As a part of reporting I want to get some values from database.
Also I included filtering in report UI, like :
select * from invoice where id in (92)
So I am making the postgres statement dynamically(here 92 is the value getting from UI and assigning dynamically). But I want to return all data without any condition if the user select no option, id in this case (no filtering). So how can I handle the "in" clause to return all data without any filtering in this case.
I am asking for a common term that can be included in 'in' clause, so it retun all rows without filtering.
Thanks!
One method is using logic like:
where (v_id is null) or (id = v_id)
Note: be careful about the use of in. It probably will not do what you intend if you expect multiple values to match.
SELECT matnr ersda ernam laeda
FROM mara
INTO CORRESPONDING FIELDS OF TABLE gt_mara
UP TO 100 ROWS.
At this point I have 100 entries in the itab gt_mara.
SELECT aenam vpsta pstat lvorm mtart
FROM mara
INTO CORRESPONDING FIELDS OF TABLE gt_mara
FOR ALL ENTRIES IN gt_mara
WHERE matnr = gt_mara-matnr AND
ersda = gt_mara-ersda AND
ernam = gt_mara-ernam AND
laeda = gt_mara-laeda.
At this point I have 59 entries. Which makes sense. This code is buggy, because it might be modifying the selection criteria at run time.
Anyway what i intended was this: select the first 4 fields of the table at one point, and then select the other 5 at some other.
Of course, this is just an example. Perhaps the second select would be done on a different table with the same key or with a different number of fields.
So can this even be done?
Are there more efficient methods to achieve this than what comes to my mind by default (redoing the complete select) ?
Ok I think the essence of your question is more about whether you can update certain unfilled fields in an internal table directly through a second select statement.
The answer is no. Your second select statement would replace the contents in table gt_mara, so you would be left with an internal table where the first 4 fields are blank, and the last 5 are filled.
The best you could do is something like this:
SELECT matnr ersda ernam laeda
FROM mara
INTO CORRESPONDING FIELDS OF TABLE gt_mara
UP TO 100 ROWS.
SELECT matnr aenam vpsta pstat lvorm mtart
FROM mara
INTO CORRESPONDING FIELDS OF TABLE gt_mara2
FOR ALL ENTRIES IN gt_mara
WHERE matnr = gt_mara-matnr AND
ersda = gt_mara-ersda AND
ernam = gt_mara-ernam AND
laeda = gt_mara-laeda.
loop at gt_mara2 into ls_mara.
modify gt_mara from ls_mara transporting aenam vpsta pstat lvorm mtart
where matnr = ls_mara-matnr.
endloop.
This is obviously quite inefficient, which is why you would always try to make the database do as much of the work for you before you bring the data back to the application server. Obviously if the data is coming from the same table selecting it all in one go is going to be your best option. In most cases even if the data is in different tables you would be better off creating a view or using a join.
In rare cases it is necessary to loop at your internal table to fill in some fields that were not available to you when you did the original select.
Either SELECT everything you need right away (which is the preferred solution if the data comes from the same table) or SELECT the additional stuff later (which is a good idea if the stuff comes from a different table that is not used for the first selection). For assembling the result set, the database usually needs to access the entire dataset anyway, so it doesn't really hurt to select some additional fields - in contrast to hitting the database again with a massive SELECT statement (if the FOR ALL ENTRIES table gets large). Also bear in mind that - depending on the kind of processing you're doing - the contents of the table might have changed in the meantime. If the database transaction (LUW) ends (which is always the case between dialog steps), you loose the database-level transaction isolation.
I have the following query called searchit
SELECT 2 AS sourceID, BLOG_COMMENTS.bID, BLOG_TOPICS.Topic_Title,
BLOG_TOPICS.LFD, BLOG_TOPICS.LC,
BLOG_COMMENTS.Comment_Narrative
FROM BLOG_COMMENTS INNER JOIN BLOG_TOPICS
ON BLOG_COMMENTS.bID = BLOG_TOPICS.bID
WHERE (BLOG_COMMENTS.Comment_Narrative LIKE #Phrase)
This query executes AND returns the correct results in the query builder!
HOWEVER, the query needs to run in code-behind, so I have the following line:
DataTable blogcomments = btad.searchit(aphrase);
There are no null fields in any row of any column in EITHER of the tables. The tables are small enough I can easily detect null data. Note that bID is key for blog_topics and cID is key for blog comments.
In any case, when I run this I get the following error:
Failed to enable constraints. One or more rows contain values
violating non-null, unique, or foreign-key constraints.
Tables have a 1 x N relationship, many comments for each blog entry. IF I run the query with DISTINCT and remove the Comment_Narrative from the return fields, it returns data correctly (but I need the other rows!) However, when I return the other rows, I get the above error!
I think tells me that there is a constraint on the return table that I did not put there, therefore it must somehow be inheriting that constraint from the call to the query itself because one of the tables happens to have a primary key defined (which it MUST have). But why does the query work fine in the querybuilder? The querybuilder does not care that bID is duped in the result (and it should not be), but the code-behind DOES care.
Addendum:
Just as tests,
I removed the bID from the return list and I still get the error.
I removed the primary key from blog_topics.bID and I get the same error.
This kinda tells me that it's not the fact that my bID is duped that is causing the problem.
Another test:
I went into the designer code (I know it's nasty, I'm just desperate).
I added the following:
// zzz
try
{
this.Adapter.Fill(dataTable);
}
catch ( global::System.Exception ex )
{
}
Oddly enough, when I run it, I get the same error as before AND it doesn't show the changes I've made in the error message:
Line 13909: }
Line 13910: BPLL_Dataset.BLOG_TOPICSDataTable dataTable = new BPLL_Dataset.BLOG_TOPICSDataTable();
Line 13911: this.Adapter.Fill(dataTable);
Line 13912: return dataTable;
Line 13913: }
I'm stumped.... Unless maybe it sees I'm not doing anything in the try catch and is optimizing for me.
Another addendum:
Suspecting that it was ignoring the test code I added to the designer, I added something to the catch. It produces the SAME error and acts like it does not see this code. (Well, okay, it DOES NOT see this code, because it prints out same as before into the browser.)
// zzz
try
{
this.Adapter.Fill(dataTable);
}
catch ( global::System.Exception ex )
{
System.Web.HttpContext.Current.Response.Redirect("errorpage.aspx");
}
The thing is, when I made the original post, I was ALREADY trying to do a work-around. I'm not sure how far I can afford to go down the rabbit hole. Maybe I read the whole mess into C# and do all the joins and crap myself. I really hate to do that, because I've only recently gotten out of the habit, but I perceive I'm making a good faith effort to use the the tool the way God and Microsoft intended. From wit's end, tff.
You don't really show how you're running this query from C# ... but I'm assuming either as a straight text in a SqlCommand or it's being done by some ORM ... Have you attempted writing this query as a Stored Procedure and calling it that way? The stored Procedure would be easier to test and run by itself with sample data.
Given the fact that the error is mentioning null values I would presume that, if it is a problem with the query and not some other element of your code, then it'd have to be on one of the following fields:
BLOG_COMMENTS.bID
BLOG_TOPICS.bID
BLOG_COMMENTS.Comment_Narrative
If any of those fields are Nullable then you should be doing a COALESCE or an ISNULL on them before using them in any comparison or Join. It's situations like these which explain why most DBAs prefer to have as few nullable columns in tables as possible - they cause overhead and are prone to errors.
If that still doesn't fix your problem, then COALESCE/ISNULL all fields that are nullable and are being returned by this query. Take all null values out of the equation and just get the thing working and then, if you really need the null values to be null, go back through and remove the COALESCE/ISNULLs one at a time until you find the culprit.
My problem came from ignorance and a bit of dullness. I did not realize that just because a field is a key in the sql table does mean it has to be a key in the tableadapter. If one has a key field defined in the SQL table and then creates a table adapter, the corresponding field in the adapter will also be a key. All I had to do was unset the key field in the tableadapter and it worked.
Solution:
Select the key field in the adapter.
Right click
Select "Delete Key" (keeps the field, but removes the "key" icon)
That's it.