are there commands similar to WEB STOP SERVER and STOP SQL SERVER but to reject new connections on my 4d server?
i found out that by using the On Server Open Connection Database Method , i can reject new connections by returning a value different than 0 as seen in the doc
If you do not return a value in $0, thereby leaving the variable undefined or initialized to zero, 4D Server assumes that the database method accepts the connection. If you do not accept the connection, you return a non-null value in $0.
so i just change the return value $0 under the conditions i need
If(*some conditions*)
$0:1
End If
Related
I am trying to set up Data Fusion MySQL connection ( JDBC plugin v. 8.0.25) with connection arguments that are not default. Somehow it won't let me use them and keep just ignoring them.
P.S. Local connection is just set to see the error and arguments that it is passing. Otherwise connection is just successful ( with default arguments )
I have tried changing values of connectTimeout and socketTimeout to 0, 99999999 etc but it just keep setting it to 20000 ms.
I except these values to overwrite since I am trying to pass my own arguments there.
This code works when the connection is made to an accdb database:
Dim customer = connection.Query(Of Klantgegevens)("Select Actief,Onderhoudscontract From Klantgegevens Where Klantnummer=#Idx", New With {.Idx = customerId}).SingleOrDefault
But the code below gives the error about the Idx parameter when the connection is made to a SQL server database that has a table with the same structure:
Dim customer = connection.Query(Of Klantgegevens)("Select Actief,Onderhoudscontract From [dbo.Klantgegevens] Where Klantnummer=#Idx", New With {.Idx = customerId}).SingleOrDefault
What is going wrong here? I had hoped that by using Dapper I would be able to write database agnostic code. But it seems that is not the case!
If you are using an ODBC/OLEDB connection, then my first suggestion would be: move to SqlClient (SqlConnection). Everything should work fine with SqlConnection.
If you can't do that for some reason - i.e. you're stuck with a provider that doesn't have good support for named parameters - then you might need to tell dapper to use pseudo-positional parameters. Instead of #Idx, use ?Idx?. Dapper interprets this as an instruction to replace ?Idx? with the positional placeholder (simply: ?), using the value from the member Idx.
This is also a good fix for talking to accdb, which has very atypical parameter usage for an ADO.NET provider: it allows named parameter tokens, but all the tokens all replaced with ?, and given values from the positions of the added parameters (not via their names).
I am trying to write ETL that collects data from many identical server into a central repository. What I'm trying to do is write one package with source address, user id and password as parameters and execute the package once per server to be copied.
Is this doable? How can I use parameters to create a source?
I meant to ask how to parametrize the connection manager (is that even a real word?), not where to store the connection parameters. The answer is simple:
Create package parameters for Server, Database, User ID and Password
Create a connection manager as part of defining a data flow component
once a connection is defined, right-click on the connection manager at the bottom of the package design screen and select "Parametrize".
Select "ServerName" in the property drop-down
Select "Use existing parameter" or create new parameter if skipped step 1
If using existing parameter, select it from the drop down
Click OK to save (gotta do it after each parameter)
Repeat steps 4-7 for the rest of the parameters
You can store parameters in a table. Query the table with a sql task and store the results in a object variable. You can then use this variable in a for loop. Use expressions in SSIS to change values of your connection during each loop iteration.
Several books outline this method. Here is a code example.
Here are some steps - hopefully I didn't miss anything. You mention a server "Address", but I'm not sure exactly what you are trying to do. This example queries multiple sql servers.
You create the variables, SQL_RS with type of object, SRV_Conn with type of string. This holds my servername. In the execute SQL task, I have a query which returns the names of sql servers I want to query. Then set the following properties:
SELECT RTRIM(Server) AS servername
FROM ServerList_SSIS
WHERE (Server IS NOT NULL)
and coalesce(exclude,'0') <> 'True'
and IsOracle is Null
Execute SQL Task > General > ResultSet = "Full Result Set"
Execute SQL Task > Result Set Tab "Result Set Name = 0", Variable Name = "User::SQL_RS"
So we have a list of server names in the SQL_RS variable now.
ForEach > Collection > Enumerator = "Foreach ADO Enumerator"
ForEach > Collection > Enumerator Configuration > ADO Object source Variable = User::SQL_RS
This maps the first column of the SQL_RS object to the SRV_Conn variable, so each iteration of the loop will result in a new value in this variable.
ForEach > Variable Mappings > Variable = User::SRV_Conn, Index = 0
Inside the ForEach are some other sql execs, performing queries on sql databases, so I need to change the ServerName of my 'MultiServer' connection. I have another connection for the initial query that got me the list of servers to query. Making the connection dynamic is done in properties of the connection - right-click the connection > properties. Click the ellipses to the right of the expressions.
Connection > Properties > Expressions > Property = ServerName, Expression = "#[User::SRV_Conn]"
Note: The index value of 0 for the variable mapping works for Native OLEDB\SQL Server Native Client. If you're using another db provider, you may need to use other index types - this makes setup more confusing.
OLEDB = 0,1
ADO.NET = #Varname
ADO = #Param1, Param2
ODBC = 1,2
Full listing here.
my application, i have used TTable.locate option in many places to move the cursor, but in only one place it will raise "EDatabaseerror : Record Not Found',
aslo it will raise for particular records only,
The Locate Option only returns boolean value, if records exist it return True,if not it return Fasle,
Why it raising Error?
am using:
Delphi 7, BDE5, Sql server 2008, am using Sql server native client driver to connect Sql server From BDE VIA ODBCE, application working fine except that place.
NOte:
am locting ttable using locaseinsensitive option,
example :
tb_user.locate('username',tb_global_user.fieldbyname('Username',[locaseinsensitive]));
this error raised from my Result form, am using this form for common search,
any helps ?
I'm connecting to a MySQL database through the Matlab Database Toolbox in order to run the same query over and over again within 2 nested for loops. After each iteration I get this warning:
Warning: com.mathworks.toolbox.database.databaseConnect#26960369 is not serializable
In Import_Matrices_DOandT_julaugsept_inflow_nomettsed at 476
Warning: com.mysql.jdbc.Connection#6e544a45 is not serializable
In Import_Matrices_DOandT_julaugsept_inflow_nomettsed at 476
Warning: com.mathworks.toolbox.database.databaseConnect#26960369 not serializable
In Import_Matrices_DOandT_julaugsept_inflow_nomettsed at 476
Warning: com.mysql.jdbc.Connection#6e544a45 is not serializable
In Import_Matrices_DOandT_julaugsept_inflow_nomettsed at 476
My code is basically structured like this:
%Server
host =
user =
password =
dbName =
%# JDBC parameters
jdbcString = sprintf('jdbc:mysql://%s/%s', host, dbName);
jdbcDriver = 'com.mysql.jdbc.Driver';
%# Create the database connection object
conn = database(dbName, user , password, jdbcDriver, jdbcString);
setdbprefs('DataReturnFormat', 'numeric');
%Loop
for SegmentNum=3:41;
for tl=1:15;
tic;
sqlquery=['giant string'];
results = fetch(conn, sqlquery);
(some code here that saves the results into a few variables)
save('inflow.mat');
end
end
time = toc
close(conn);
clear conn
Eventually, after some iterations the code will crash with this error:
Error using database/fetch (line 37)
Query execution was interrupted
Error in Import_Matrices_DOandT_julaugsept_inflow_nomettsed (line
466)
results = fetch(conn, sqlquery);
Last night it errored after 25 iterations. I have about 600 iterations total I need to do, and I don't want to have to keep checking back on it every 25. I've heard there can be memory issues with database connection objects...is there a way to keep my code running?
Let's take this one step at a time.
Warning: com.mathworks.toolbox.database.databaseConnect#26960369 is not serializable
This comes from this line
save('inflow.mat');
You are trying to save the database connection. That doesn't work. Try specifying the variables you wish to save only, and it should work better.
There are a couple of tricks to excluding the values, but honestly, I suggest you just find the most important variables you wish to save, and save those. But if you wish, you can piece together a solution from this page.
save inflow.mat a b c d e
Try wrapping the query in a try catch block. Whenever you catch an error reset the connection to the database which should free up the object.
nQuery = 100;
while(nQuery>0)
try
query_the_database();
nQuery = nQuery - 1;
catch
reset_database_connection();
end
end
The ultimate main reason for this is that database connection objects are TCP/IP ports and multiple processes cannot access the same port. That is why database connection object are not serialized. Ports cannot be serialized.
Workaround is to create a connection with in the for loop.