Execute SQL statements

To execute an SQL statement, a DataBlade® API module must send the SQL statement to the database server, where the statement is executed.

The DataBlade® API provides the following statement-execution functions for use in a DataBlade® API module:
  • mi_exec()
  • mi_exec_prepared_statement()
  • mi_open_prepared_statement()

All of these functions perform the same basic task: they send a string representation of an SQL statement to the database server, which executes it and returns statement results. The mi_exec() function is the simplest way to execute an SQL statement.

Server only: A C user-defined routine (UDR) that executes SQL statements must be registered as a variant function; that is, its CREATE FUNCTION statement must either include the VARIANT routine modifier or omit both the NOT VARIANT and VARIANT routine modifiers (VARIANT is the default).
This section provides a summary of factors to consider when choosing the DataBlade® API statement-execution function to use. It then describes the two methods for statement execution.
  • Parse, optimize, and execute the statement in one step.
  • Parse and optimize the statement to create a prepared statement. Execute the prepared statement.
Tip: Before you use a DataBlade® API function that sends an SQL statement to the database server, make sure you obtain a valid connection descriptor.