Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>From the MSDN Documentation:</p> <blockquote> <p>"Before you call Prepare, specify the data type of each parameter in the statement to be prepared. For each parameter that has a variable length data type, you must set the Size property to the maximum size needed. Prepare returns an error if these conditions are not met.</p> <p>If you call an Execute method after calling Prepare, any parameter value that is larger than the value specified by the Size property is automatically truncated to the original specified size of the parameter, and no truncation errors are returned.</p> <p>Output parameters (whether prepared or not) must have a user-specified data type. If you specify a variable length data type, you must also specify the maximum Size."</p> <p>Furthermore, "If the CommandType property is set to TableDirect, Prepare does nothing. If CommandType is set to StoredProcedure, the call to Prepare should succeed, ..."</p> </blockquote> <p>This in general is used to make sure that the end user is not using a SQL Injection technique to add or remove information you do not want them too from the database.</p> <p>I looked into it and check out this article <a href="http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlcommand.prepare.aspx" rel="noreferrer">http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlcommand.prepare.aspx</a>. Your issue is you need to define your parameters before you run .Prepare() and then set your parameters after you run .Prepare(). Right now you are doing both before. I would try something like this (Note I didn't test it so my syntax might be a bit off).</p> <pre><code>public static decimal pobierzBenchmarkKolejny(string varPortfelID, DateTime data, decimal varBenchmarkPoprzedni, decimal varStopaOdniesienia) { const string preparedCommand = @"SELECT [dbo].[ufn_BenchmarkKolejny](@varPortfelID, @data, @varBenchmarkPoprzedni, @varStopaOdniesienia) AS 'Benchmark'"; using (var varConnection = Locale.sqlConnectOneTime(Locale.sqlDataConnectionDetailsDZP)) //if (varConnection != null) { using (var sqlQuery = new SqlCommand(preparedCommand, varConnection)) { sqlQuery.Parameters.Add("@varPortfelID"); sqlQuery.Parameters.Add("@varStopaOdniesienia"); sqlQuery.Parameters.Add("@data"); sqlQuery.Parameters.Add("@varBenchmarkPoprzedni"); sqlQuery.Prepare(); sqlQuery.ExecuteNonQuery();//This might need to be ExecuteReader() sqlQuery.Parameters[0].Value = varPortfelID; sqlQuery.Parameters[1].Value = varStopaOdniesienia; sqlQuery.Parameters[2].Value = data; sqlQuery.Parameters[3].Value = varBenchmarkPoprzedni; using (var sqlQueryResult = sqlQuery.ExecuteReader()) if (sqlQueryResult != null) { while (sqlQueryResult.Read()) { } } } } </code></pre>
    singulars
    1. This table or related slice is empty.
    1. POPros and Cons of using SqlCommand Prepare in C#?
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USBen Hoffman
    1. USBen Hoffman
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. POPros and Cons of using SqlCommand Prepare in C#?
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COWhat about performance and other things? Is it only to prevent SQL Injection? I've read MSDN documentation myself prior to asking this question and the quoted part isn't realy useful regarding my questions to use it or not and if it has any performance benefits which seems to be suggested on some websites.
      singulars
      1. PO
      1. USMadBoy
    2. COMy understanding is by making everything defined it can cache and reuse the query plan. I would guess that it doesn't give you an extreme amount of benefit.
      singulars
      1. PO
      1. USBen Hoffman
    3. COIs the usage I have in code correct? I tried moving Prepare to after all Parameters are set and the error is thrown. So is it that sqlQuery.Prepare should always be used before parameters or?
      singulars
      1. PO
      1. USMadBoy
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload