Posts by jean • 904 points
39 posts
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1
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answers69
viewsA: Match table data on Linkedserver servers
You can make an insert straight from a select of course but pq do this if vc have a free tool to make data comparison from MS SQL Server? Any version of Visual Studio has a tool for data comparison…
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votes1
answer167
viewsA: Deleting using subquery and Join
In general you can do DELETE and UPDATE using joins with no problem. Usually I do like you, make first one SELECT returning all records I want to delete: Select distinct p.EVENT_ITEM_ID From…
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votes1
answer30
viewsA: How can I remove the spacing between methods and properties?
See the image below: Usually these "gaps" between the lines are "helpers" that the editor shows, things that he wants to show but that are not really written in the code. Check its properties and…
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votes3
answers658
viewsA: Compare 2 field-to-field tables
You did not specify how the result should be shown so I am proposing two options: Using these records as an example: create table contatonovo ( codigo varchar(5) null ,nome varchar(50) null ,celular…
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votes4
answers91
viewsA: Select with columns stating incorrect data
Maybe the problem is in this query snippet: FROM empresas j, informessocios i It seems that you are mixed explicit joins with implicit ones. Also never use fields like "name" or "code" as joins keys…
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votes1
answer395
viewsA: Consider NULL as 0
Use COALESCE. This SQL function takes a list of n parameters and returns the first non-null value it finds. Below follows a small example: create table tabela_exemplo ( descricao varchar(20) not…
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votes1
answer974
viewsA: SQL SERVER myth about SELECT INTO and tempdb locks
TEMPDB It is a system database and every time you use temporary tables (#Mytemptableexample) they are created in this database (not with this name but pq several sessions may be using the same name,…
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votes2
answers1061
viewsA: What are real and practical examples in the use of Stored Procedures?
Two examples: Two applications a web service made in C# and a desktop application made in Delphi need to run a business rule implemented in BD. For better maintenance and management it is better…
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votes2
answers229
viewsA: Dynamic SQL result sorting
If you really want to go this way you can just cast (to sweep), so you would get around the problem of columns being of different types. But note that using a clause CASE within a clause ORDER BY is…
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votes2
answers184
viewsA: How to interrupt the database query using time out in Hibernate?
It’s been a while since I did this with nhibernate. Look for references to connection properties on Hibernate. In the same file/code where you set the connection you can set the timeout. below some…
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votes3
answers2032
viewsA: Select from the last records sorted by 1 field
As the bfavaretto commented you should already be using the best option for your requirements. Note you want to: The last three records. Displays them sorted by name. For the first requirement you…
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answers511
viewsA: Filters or Sort, which should be the first when creating an index in the database
Index creation order does not change the use of the index. As for leaving an index covering several columns I suggest you create two, one for the filters and the other for sorting because the DBMS…
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votes1
answer983
viewsA: How to measure time complexity of sorting algorithms?
You’re trying to make a correlation between theory and practice and as we know in theory both are equal, in practice no. Theory: Using O() notation you study the behavior of the algorithm, i.e. how…
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votes3
answers906
viewsA: Can a primary key be used on a foreign key?
1) The only restriction for foreign keys is that they should point to a single key. Note that all PK, by definition, is a single key. Think about it: the foreign key indicates who is the parent…
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votes4
answers860
viewsA: Select with indefinite amount of conditions
It depends on the complexity of the functionality you want to implement and the size of your application. For a small and simple application you can fix up to three fields, require at least the…
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votes3
answers2122
viewsA: Is it possible to create a Javascript database?
Short answer: No! Elaborating a little more: Depends of your needs. A DBMS is a powerful tool to persist your data. Therefore the name DATABASE, your data is saved and protected and when you need…
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votes2
answers577
viewsA: Is it good practice to keep foreign key columns redundant?
You didn’t ask for personal opinion, asked if it was good practice. In addition Stackoverflow does not propose to answer questions based on personal opinion and recommends that no questions of this…
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votes4
answers818
viewsA: Database being changed/Hacked
This really looks like SQL Injection Attack. The problem per se not get but dynamic SQL, which mounts the script on the fly. Sanitizing data helps but there are hacker techniques of quoting using…
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answers508
viewsA: When is it recommended to use decreasing indexes?
Depends on your need. By default the indexes are created in ascending order because, in general, the values (usually ids) are generated increasing. This way the new (larger) values go to the end of…
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answers2325
viewsA: Order By - Leave specific record for first
I prefer an alternative where I don’t need to create a dynamic order by select Store_Name, Sales, Date, case when store_name = 'Boston' then 0 else 9 end as Orderby from tabela order by orderby…
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votes4
answers1022
viewsA: How to keep column 'order' in sequence even after editing the order of records?
I understand you’re dragging names from one position to another. In this case you would only need a pair (Id, Order)Origin and (Id, Order)Destination. Following his example: id order name 1 1 Fabio…
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answers2357
viewsA: Good practices for storing logs
It depends a little on the technology you are using but @guerra is right. Because Trigger makes maintenance difficult and you will have to implement Trigger in n tables. It is not practical if you…
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answers6990
viewsA: CASE error in ORACLE’s WHERE
You don’t need CASE for this, just use common boolean logic. AND( (t1.cd1 IS NOT NULL AND t2.cd1 = t1.cd1) OR (t3.cd2 = t1.cd2) ) BTW, yes! you can do something like: where column_1 =…
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answers2883
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answer423
viewsA: Error creating SQL Server 2005 database with compressed disk
In addition to not being considered a good practice (IO of disks can be intense in a database, requiring compression/decompression all the time) the SSMS is not willing to create that . MDF unless…
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answers14419
viewsA: Which database should I use in a small desktop application?
You said you store sensitive data in excel? For sensitive data and C# I would prefer to use MS Sql. For not so important data you can use any one. "smaller" bases (surely its base is small) can use…
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answers491
viewsA: Logica de Distribuição Igualada
I don’t know any formal solution but if I were to "invent" one I would do the following. Use a counter for your list of variables. Looping the list, inserting each variable in the sequence and…
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answers1494
viewsA: Filter table before applying a LEFT JOIN
As a general rule you only leave in Join what is necessary for the tables to be compared to each other, in your case only c.Client = and.Client. And you leave in the Where only what is the filter,…
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answers1395
viewsA: Problem using 'Google Fonts'
Have you tried the Icomoon? It has great features for editing and downloading files from sources. I use primarily to create icons as fonts but I believe it can be used as fonts to write texts (well,…
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answers462
viewsA: Internet Explorer, should I still be worried about him?
Yes! But it depends on the version. See this chart that I built on Statcounter (Using by version last year): http://gs.statcounter.com/#browser_version_partially_combined-BR-Monthly-201301-201401…
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answers59138
viewsA: How to raise a number to a power without using the Math. h library?
Welcome to the world of computational mathematics where various functions such as Pi, square root, sine and cosene are implemented as the summations of infinite convergent series. There’s a similar…
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answers4039
viewsA: Why use Bytes instead of Image? What is the best practice?
Another solution is not to store blobs in the database in any way. This is especially good for performance when you upload/donwload large files. From experience I have seen that it is much more…
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answers2553
viewsA: Database structure for multi-language system
To make a multi language system you will have to refactor it virtually all. Adding an extra column per language as you intend is not considered a good practice (it is a gambiarra). Ideally you would…
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answers2949
viewsA: How to use multiple SQL commands (in the case delete on ORACLE) in one line only on C#?
Use the boolean OR on your Where comand.CommandText = "DELETE FROM TB_CR_INDICADOR WHERE COD_INDICADOR = " + codigo + "; DELETE FROM TB_CR_INDICADOR_PERIODO WHERE COD_INDICADOR = " + codigo + ";…
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answers7830
viewsA: Is giving a "SELECT" before an "INSERT" a safe way of not having duplicate records?
Without changing the base just by changing the dynamic query would be something +- like this: begin tran with isolation level read commited update table where id = @iD if (@@rowcount = 0) -- se não…
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answer1046
viewsA: What is the best way to make an online database backup
The problem is bandwidth/file size. I don’t know if mysql can backup differently. If it was an MS SQL or Oracle I would do a differential backup per day and one full per week (probably, but that…
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votes4
answers1443
viewsA: SQL query that meets a parameter that is a set
First you must create a table of diseases and another of symptoms and then one of relationship between diseases and symptoms. For appointments you should do something pareciso, one of consultations…
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answers4914
viewsA: Do not allow saving image of a web page
Superimpose an invisible div on the image, when trying to click on the image the user will be clicking on the div. But look at Sergio’s answer, he’s right.
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answers29661
viewsA: How do I know if a column exists in an SQL Server table?
Try this, works for aSQL Server 2008+ and changes little to previous versions. if exists( select * from sys.sysobjects so join sys.syscolumns sc on sc.id = so.id where so.xtype = N'U' and so.name…