Hi everyone,
Today I want to talk about executing SQL statements in X++ on both the AX database and external databases. This is something probably every AX developer will have to do at some point.
You’ll want to do this for many reasons; to execute stored procedures, to improve performance, to get data from an external database, and so on.
I will provide samples for two classes:
- Connection (Execute SQL statement on current AX database)
- ODBCConnection (Execute SQL statement on external database)
I will not cover the ADO connection (CCADOConnection class), because it doesn’t work when you run it on server (or in batch), and I don’t like that. If you do, try to convince me ;-).
Executing direct SQL on the current AX database
When you execute a SQL statement, there are two options:
- either you did a select and you expect a result to be returned
- or you did insert/update/delete and you don’t expect a result.
The first sample is for a SQL statement that returns a result:
{
Connection connection;
Statement statement;
str query;
Resultset resultSet;
;
// create connection object
connection = new Connection();
// create statement
statement = connection.createStatement();
// Set the SQL statement
query = 'select name from CustTable';
// assert SQL statement execute permission
new SqlStatementExecutePermission(query).assert();
// when the query returns result,
// loop all results for processing
//BP Deviation documented
resultSet = statement.executeQuery(query);
while(resultSet.next())
{
// do something with the result
info(resultSet.getString(1));
}
// limit the scope of the assert call
CodeAccessPermission::revertAssert();
}
Note: this is a main method, put it in a class. Also note that it has to run on server.
Now if you do an update/delete/insert, you will want to do something like this:
{
Connection connection;
Statement statement;
str query;
;
// create connection object
connection = new Connection();
// create statement
statement = connection.createStatement();
// Set the SQL statement
query = "insert into CustTable (AccountNum, Name, RecId) values ('demo', 'demo', 2)";
// assert SQL statement execute permission
new SqlStatementExecutePermission(query).assert();
//BP Deviation documented
statement.executeUpdate(query);
// limit the scope of the assert call
CodeAccessPermission::revertAssert();
}
You can find more info about the executeQuery() and executeUpdate() methods on msdn:
Statement Class
Executing direct SQL on an external database using ODBC
Again, we have to differentiate between queries that return a result and those that don’t.
The following code sample retrieves records from an external database and processes the result:
{
Statement statement;
str query;
Resultset resultSet;
LoginProperty loginProperty;
OdbcConnection odbcConnection;
;
loginProperty = new LoginProperty();
loginProperty.setDSN('YOURDSN');
odbcConnection = new OdbcConnection(loginProperty);
// Create new Statement instance
statement =odbcConnection.CreateStatement();
// Set the SQL statement
query = 'select name from CustTable';
// assert SQL statement execute permission
new SqlStatementExecutePermission(query).assert();
// when the query returns result,
// loop all results for processing by handler
//BP Deviation documented
resultSet = statement.executeQuery(query);
while(resultSet.next())
{
// do something with the result
info(resultSet.getString(1));
}
// limit the scope of the assert call
CodeAccessPermission::revertAssert();
}
As you can see, the code is pretty similar. The main difference is that we are using ODBC classes, including the LoginProperty class.
In this example, I use a DSN (Data Source Name) that I configured on the AOS server. The DSN contains a reference to the server and database you want to connect to, and also what user credentials should be used to connect to the database. This is a lot safer than storing them in AX.
If you don’t know how to create a DSN, there are plenty of tutorials on the web.
To update/delete/update, the code is more or less the same:
{
Statement statement;
str query;
LoginProperty loginProperty;
OdbcConnection odbcConnection;
;
loginProperty = new LoginProperty();
loginProperty.setDSN('YOURDSN');
odbcConnection = new OdbcConnection(loginProperty);
// Create new Statement instance
statement =odbcConnection.CreateStatement();
// Set the SQL statement
query = "insert into CustTable (AccountNum, Name, RecId) values ('demo', 'demo', 2)";
// assert SQL statement execute permission
new SqlStatementExecutePermission(query).assert();
// when the query returns result,
// loop all results for processing by handler
//BP Deviation documented
statement.executeUpdate(query);
// limit the scope of the assert call
CodeAccessPermission::revertAssert();
}
If you feel that something is missing in these examples, just ask.
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