Calling Stored Procedures
You can invoke a stored procedure using ApacheImpalaCommand in the same way as any other SQL stored procedure. To instantiate a ApacheImpalaCommand object, provide the name of the stored procedure and a ApacheImpalaConnection instance as arguments to the constructor. Set the value of the CommandType property to "StoredProcedure" and add the parameters as key-value pairs to the Parameters collection of the ApacheImpalaCommand instance.
C#
string connectionString = "Server=127.0.0.1;Port=21050;";
using (ApacheImpalaConnection connection = new ApacheImpalaConnection(connectionString)) {
ApacheImpalaCommand cmd = new ApacheImpalaCommand("SearchSuppliers", connection);
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.Add(new ApacheImpalaParameter("@Country", "US"));
// Add other parameters as needed ...
ApacheImpalaDataReader rdr = cmd.ExecuteReader();
while (rdr.Read()) {
for (int i = 0; i < rdr.FieldCount; i++) {
Console.WriteLine(rdr.GetName(i) + " --> " + rdr[i]);
}
Console.WriteLine();
}
}
VB.NET
Dim connectionString As String = "Server=127.0.0.1;Port=21050;"
Using connection As New ApacheImpalaConnection(connectionString)
Dim cmd As New ApacheImpalaCommand("SearchSuppliers", connection)
cmd.CommandType = CommandType.StoredProcedure
cmd.Parameters.Add(New ApacheImpalaParameter("@Country", "US"))
' Add other parameters as needed ...
Dim rdr As ApacheImpalaDataReader = cmd.ExecuteReader()
While rdr.Read()
For i As Integer = 0 To rdr.FieldCount - 1
Console.WriteLine(rdr.GetName(i) + " --> " + rdr(i))
Next
Console.WriteLine()
End While
End Using
Alternatively, you can set the parameters of a stored procedure in the text of the command. The support for stored procedure statements follows the standard form shown below:
"EXECUTE my_proc @first = 1, @second = 2, @third = 3;" "EXEC my_proc @first = 1, @second = 2, @third = 3;"
To execute a parameterized query, add parameters as key-value pairs to the Parameters collection of the ApacheImpalaCommand instance.
C#
string connectionString = "Server=127.0.0.1;Port=21050;";
using (ApacheImpalaConnection connection = new ApacheImpalaConnection(connectionString)) {
ApacheImpalaCommand cmd = new ApacheImpalaCommand("EXECUTE SearchSuppliers Country = @Country;", connection);
cmd.Parameters.Add(new ApacheImpalaParameter("@Country", "US"));
// Add other parameters as needed ...
ApacheImpalaDataReader rdr = cmd.ExecuteReader();
while (rdr.Read()) {
for (int i = 0; i < rdr.FieldCount; i++) {
Console.WriteLine(rdr.GetName(i) + " --> " + rdr[i]);
}
Console.WriteLine();
}
}
VB.NET
Dim connectionString As String = "Server=127.0.0.1;Port=21050;"
Using connection As New ApacheImpalaConnection(connectionString)
Dim cmd As New ApacheImpalaCommand("EXECUTE SearchSuppliers Country = @Country;", connection)
cmd.Parameters.Add(New ApacheImpalaParameter("@Country", "US"))
' Add other parameters as needed ...
Dim rdr As ApacheImpalaDataReader = cmd.ExecuteReader()
While rdr.Read()
For i As Integer = 0 To rdr.FieldCount - 1
Console.WriteLine(rdr.GetName(i) + " --> " + rdr(i))
Next
Console.WriteLine()
End While
End Using