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This article will give you a detailed explanation on how to implement the ADO test program. The editor thinks it is very practical, so I share it with you for reference. I hope you can get something after reading this article.

When operating on Sql Server and Oracle, the connection was closed directly after the execution was completed. The returned parameters can be handled as they please and will not go wrong. Note that using COM interoperability to access ADO data will greatly degrade performance.

I don't know how many people here use Sybase for database development, but I can't stand it. Using the ADO test program, broke through a lot of resistance, and finally the system is running normally, we need to do further processing: increase data permissions. We used to judge by the result set returned directly by the function on Sql Server.

But Sybase does not support functions, so you have to use stored procedures to return a conditional string that determines permissions for dynamic execution. The problem is to take out the output parameters and always prompt "Command has been closed". It's strange that it was Open when it was executed and Connection. Wrote an ADO test program:

AseConnection con = new AseConnection ("Data Source='SYBASE'; Port=5000; UID='sa'; PWD=''; Database='data';Connection Timeout='300';"); AseCommand com = new AseCommand ("GetDataRightSQL", con); com.CommandType = System.Data.CommandType.StoredProcedure; try {AseParameter prm = new AseParameter ("@ UserID", 1); / / prm.Direction = System.Data.ParameterDirection.Input; com.Parameters.Add (prm); prm = new AseParameter ("@ Category", "Department") Com.Parameters.Add (prm); com.Parameters.Add (new AseParameter ("@ FieldName", "Dept_ID")); prm = new AseParameter ("@ returnSql", AseDbType.VarChar, 250); prm.Direction = System.Data.ParameterDirection.Output; com.Parameters.Add (prm); con.Open (); com.ExecuteNonQuery (); Console.WriteLine (com.Parameters ["@ returnSql"] .value)

Since we have a data layer that specializes in database operations, we begin to suspect that the encapsulation is not good. After checking N times, I don't know what went wrong. The ADO test program always thought that there was something wrong with the output parameter type. I tried it several times, and the length was changed. no way.

It was later noticed that when the trace was executed successfully, it always made an error when fetching parameters.

Take a look at the error message "Command has been closed" again, dizzy! The ADO test program will not require the database connection to remain in the Open state when fetching parameter values, will it? Modify the test code:

AseParameter prm = new AseParameter ("@ UserID", 1); / / prm.Direction = System.Data.ParameterDirection.Input; com.Parameters.Add (prm); prm = new AseParameter ("@ Category", "Department"); com.Parameters.Add (prm); com.Parameters.Add (new AseParameter ("@ FieldName", "Dept_ID"); prm = new AseParameter ("@ returnSql", AseDbType.VarChar, 250); prm.Direction = System.Data.ParameterDirection.Output Com.Parameters.Add (prm); con.Open (); com.ExecuteNonQuery (); con.Close (); / / early shutdown of database Console.WriteLine (com.Parameters ["@ returnSql"] .value) This is the end of the article on "how to implement the ADO test program". I hope the above content can be of some help to you, so that you can learn more knowledge. if you think the article is good, please share it for more people to see.

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