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..because one of the three subqueries returns more than one row.
(SELECT account_number FROM patients WHERE file_no = param_file_no);
(SELECT account_number FROM accounts WHERE account_id = param_account_id);
(SELECT price_list_id FROM accounts WHERE account_number = param_account_number);
Meaning that the table holds more than a single record with the requested Id.
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Quote: Meaning that the table holds more than a single record with the requested Id.
True, this is the main reason for such errors. Many resolution are available for this errors.
1) Use Top 1 keyword i.e.
(SELECT TOP 1 account_number FROM patients WHERE file_no = param_file_no);
(SELECT TOP 1 account_number FROM accounts WHERE account_id = param_account_id);
(SELECT TOP 1 price_list_id FROM accounts WHERE account_number = param_account_number);
2) Some of your data require 1 or more condition (filter) in your sql query.
3) If any duplicate entry found, Please remove.
Maulik Dusara
Sr. Sofware Engineer
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MaulikDusara wrote: True, this is the main reason for such errors. Many resolution are available for this errors.
1) Use Top 1 keyword i.e.
That's assuming that there's more of those records allowed in the table, and being an "Id", this COULD lead to an inconsistent database - exaggerating the problem.
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I agree with Eddy, while top 1 fixes this problem it ignores the underlying data problem that the user was expecting 1 record per ID and is not getting the correct result.
Never underestimate the power of human stupidity
RAH
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Quote: not getting the correct result.
I also agree and I also mentioned that Quote: Many resolution are available for this errors
Please also check my other resolutions.
Maulik Dusara
Software Engineer/Team Leader
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MaulikDusara wrote: Please also check my other resolutions.
That's the point; he should not "try resolutions", but analyze the bug; if there are multiple records coming back on a key-field selection, chances are that there's an inconsistency. Selecting the "top 1" might hide that problem a little longer.
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I have drafted a rough design of a new database for a job application web site. I have a quintillion lookup tables with no more than a primary key and a string column, e.g. Province, with Id int and Province nvarchar(50). In this case, Province seems a natural and logical name for the description field, but in others the description is more vague, and better named as simple Description.
Now, if I use the name Description for all description columns in the DB I gain the opportunity to use more generalized T-SQL and C# code to deal with lookup tables, but I lose in semantics, especially where e.g. a WorkCategory lookup table grows to represent a business entity and not just a value domain; then Description would become less meaningful among more than just two columns.
I understand there is no black and white, clear cut answer to this question, but I am only asking for suggestions and input from people who may have faced similar dilemmas before.
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Do NOT go down the path of description, do precisely what you are doing, name your fields intelligently and when nothing comes to mind only then use description. It'll save you a crap load of refactoring in the future.
I use a code generator which reduces the cost of refactoring and I still get irritated when I do this.
Never underestimate the power of human stupidity
RAH
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Mycroft Holmes wrote: I use a code generator which reduces the cost of refactoring
So do I, being the T4 based code generated by the EF Wizard or Power Tools, but I'm interested in what causes the mountains of refactoring you are warning me against. Is it, as I suspect, when you need to rename Description to something more specific?
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Brady Kelly wrote: Is it, as I suspect, when you need to rename Description to something more specific?
You suspect correctly, although I have to admit my problem is caused more by using views and never allowing Select * From ViewName
But I find it immensely irritating to get to the reporting phase of an app only to wish I had used something more descriptive than description. And having to rename them in a query when you have 5 description fields hanging off a Fact table view!
Never underestimate the power of human stupidity
RAH
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I see. I'm currently on a big renaming exercise, and will try and reduce my Description usage. Luckily that field isn't used in any FK's.
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I mostly agree with Mycroft; the odds definitely favour what he recommends.
But as he and I seem to work on very different types of systems, I generally never display the column headings and in many cases ( Code , Meaning ) will suffice. Yet in many others a broader range of text values is required, so more descriptive names are suitable; one such I have here has ( ID , Tag , Description ) -- the Tag is used for a Dictionary and the Description is used in a ComboBox. There's another example here that pre-dates me wherein four different text values are required ( ID , Name , Description , LongName , ShortName ).
Oh, I just remembered another one that I created a week or two ago ( Code , Meaning , Description ) -- the Description is intended only as documentation for developers looking at the table; this table contains flags to be used in bitmaps.
What matters more is using names like "Name" and "Description" which are or may be reserved words -- you should probably avoid that, and by being in the habit of using more descriptive names you may never need to worry about that.
Consider each table on its own, don't try to enforce a single rule on all of them, but err on the side of caution. As I hope I showed here, habits are hard to break, so please try not to follow my path. 
(Now I'm picturing Jacob Marley...)
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PIEBALDconsult wrote: Description is intended only as documentation for developers looking at the table
That kind of info I am storing in a separate data dictionary, which has not yet moved beyond an Excel doc, but I am seriously considering writing something to use SQL Server's Extended Properties for data dictionary data.
PIEBALDconsult wrote: What matters more is using names like "Name" and "Description" which are or may be reserved words -- you should probably avoid that, and by being in the habit of using more descriptive names you may never need to worry about that.
Yes, and even names that aren't reserved but are prickly, like having a table called ReferenceType with Id and Type columns. I have avoided all of those things.
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Brady Kelly wrote: SQL Server's Extended Properties
Can those be applied to individual rows? Even if so, would a developer look there when perusing the table?
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Duh, no.  I had crossed channels in my mind when I write that. 
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This week I very quickly put together a simply database of some fifty tables and about three hundred columns all told, with every table having at least one foreign key. Then I noticed some spelling mistakes and or typos in some table and column names, and this inspired me to develop a tool that can perform a spelling check on all identifiers used in all database objects.
This is no mean feat. My rought draft strategy is to
1. Build a list of all identifiers in the database. To start with, I will limit this to table, column, view, and key and index names.
2. Use patterns and heuristics to split identifiers into word parts and ignore parts such as 'FK_' etc.
3. Check spellings of split identifiers, and those not split, and mark possible errors.
4. Where an error is e.g. found and corrected in a column name, correct all other occurrences of that column name in the DB.
I know none of these is simple, but I think this could make an interesting hobby project and an article or two, if I start simple and incrementally make the app more intelligent.
What warnings, criticisms, suggestions, or general comments do you have?
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You are taking all the fun out of debugging. The hours of pure joy spent trying to understand a bug just because my typing skills were dyslexic are boundless. And you want to take this away!
Serious note:  good idea and an article would be a good read for sure. 
Chris Meech
I am Canadian. [heard in a local bar]
In theory there is no difference between theory and practice. In practice there is. [Yogi Berra]
posting about Crystal Reports here is like discussing gay marriage on a catholic church’s website.[Nishant Sivakumar]
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I would be very happy to read such an article.
Lobster Thermidor aux crevettes with a Mornay sauce, served in a Provençale manner with shallots and aubergines, garnished with truffle pate, brandy and a fried egg on top and Spam - Monty Python Spam Sketch
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Are you going to look into only key fields or all field names, for us dyslexics who can spell ModifiedBy in multiple ways.
All fields would actually be simpler, build a distinct from sysobjects, then do some matching and soundex comparisons might be just as useful.
It is going to totally fai on some naming conventions but for us who use sensible naming it could be good.
Never underestimate the power of human stupidity
RAH
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I'm going to do all columns. My naming conventions nearlly always use full names, e.g.
SecondaryEducation ExamNumber
SecondaryEducation HighestLevelId
SecondaryEducation HighestLevelOther
SecondaryEducation SchoolName
SecondaryEducation EnglishProficiencyLevelId
SecondaryEducation EnglishProficiencyInstitution
SecondaryEducationLevel Id
SecondaryEducationLevel Description
I'll be using a set of algorithms to split names in various ways, hopefully into separate English words, as my example above would do quite nicely. Then I'll have a configurable set of standard non- or semi-English tokens that can be checked for deviation from their definitions, and good old ignore lists.
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I have some vb code around somewhere that split words fairly reliably, used to make DGV headers readable before MS built it into their DGV.
Never underestimate the power of human stupidity
RAH
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Maybe you should article it.
There, how's that for a really dirty verbing? 
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That entire phrase belongs in the nasty buzzword forum.
It would barely make a tip IIRC. I'll try and dig it up if you feel you have a need.
Never underestimate the power of human stupidity
RAH
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I've found quite a list of splitting algorithms, so no need for you to go digging for it now, but thanks anyway.
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Brady Kelly wrote: into separate English words
I would check for consistency first -- if a token is repeated many times, then it is probably what you meant and a token with a small Levenshtein Distance from it is probably misspelled.
On one project I decided that (by golly) I was going to spell "threshold" with three Hs (threshhold), as it's pronounced! I later changed it back, but before doing so I'd want the dozen "threshhold"s to outweigh an outlying "threshold".
Likewise, an incorrectly named item could be a valid word.
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