How to Use User-Defined Scalar Functions in Oracle and SQL Server

Description

User-defined scalar functions in Oracle and SQL Server can be called from Alpha Anywhere.

Discussion

You can either use the function in a SELECT statement, or execute the call in a PL/SQL script. The complete Xbasic scripts are shown below for both Oracle and SQL Server. In summary:

The correct syntax to select the result of a scalar function in Oracle is:

? c.Execute("select COUNT_EMP(:lower, :upper) as l_Count from  dual")
?c.resultset.data("l_count")

To retrieve output parameters from a stored procedure or function you can add an argument to the SQL::Arguments object for each output parameter as follows:

dim args as sql::arguments
args.add("l_count", 0, SQL::ArgumentUsage::OutputArgument)
? c.execute("begin :l_count := COUNT_EMP(:lower, :upper); end;",  args)
? args[3].Data

The value SQL::ArgumentUsage::OutputArgument indicates that the parameter is output only. There is an enumerated value for each of (input, output and input/output).

The SQL is wrapped in a BEGIN/END pair. This seems to be required by OCI for the script to execute properly.

 Calling a user defined scalar function using Oracle

Getting the result of the function using a SELECT statement

dim c as sql::connection
? c.open( ("::Name::Oracle") )?c.open( ("::Name::Oracle") )
dim args as sql::arguments
args.add("lower", 1)
args.add("upper", 100)
? c.execute("select COUNT_EMP(:lower, :upper) as l_Count from dual", args)
? c.resultset.data("l_count")

Getting the result of the function using SQL::Arguments

dim c as sql::connection
? c.open( ("::Name::Oracle") )
dim args as sql::arguments
args.add("lower", 1)
args.add("upper", 100)
args.add("l_count", 0, SQL::ArgumentUsage::OutputArgument)
? c.execute("begin :l_count := COUNT_EMP(:lower, :upper); end;",  args)
? args[3].Data

 Calling a user defined scalar function using SQL Server

Getting the result of the function using a SELECT statement

dim c as sql::connection
? c.open( ("::Name::SQLServer") )
dim args as sql::arguments
args.add("lower", 1)
args.add("upper", 100)
? c.execute("select dbo.COUNT_EMP(:lower, :upper) as l_Count",  args)
? c.resultset.data("l_count")

Getting the result of the function using SQL::Arguments.

dim c as sql::connection
? c.open( ("::Name::SQLServer") )
dim args as sql::arguments
args.add("lower", 1)
args.add("upper", 100)
args.add("l_count", 0, SQL::ArgumentUsage::OutputArgument)
? c.execute("select :l_count = dbo.COUNT_EMP(:lower, :upper)",  args)
? args[3].Data