Method: PG::Connection#exec_prepared

Defined in:
ext/pg_connection.c

#exec_prepared(statement_name[, params, result_format[, type_map]]) ⇒ PG::Result #exec_prepared(statement_name[, params, result_format[, type_map]]) {|pg_result| ... } ⇒ Object Also known as: async_exec_prepared

Execute prepared named statement specified by statement_name. Returns a PG::Result instance on success. On failure, it raises a PG::Error.

params is an array of the optional bind parameters for the SQL query. Each element of the params array may be either:

a hash of the form:
  {:value  => String (value of bind parameter)
   :format => Integer (0 for text, 1 for binary)
  }
or, it may be a String. If it is a string, that is equivalent to the hash:
  { :value => <string value>, :format => 0 }

PostgreSQL bind parameters are represented as $1, $2, $3, etc., inside the SQL query. The 0th element of the params array is bound to $1, the 1st element is bound to $2, etc. nil is treated as NULL.

The optional result_format should be 0 for text results, 1 for binary.

type_map can be a PG::TypeMap derivation (such as PG::BasicTypeMapForQueries). This will type cast the params from various Ruby types before transmission based on the encoders defined by the type map. When a type encoder is used the format and oid of a given bind parameter are retrieved from the encoder instead out of the hash form described above.

If the optional code block is given, it will be passed result as an argument, and the PG::Result object will automatically be cleared when the block terminates. In this instance, conn.exec_prepared returns the value of the block.

See also corresponding libpq function.

Overloads:

  • #exec_prepared(statement_name[, params, result_format[, type_map]]) ⇒ PG::Result

    Returns:

  • #exec_prepared(statement_name[, params, result_format[, type_map]]) {|pg_result| ... } ⇒ Object

    Yields:

    • (pg_result) 


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# File 'ext/pg_connection.c', line 3447

static VALUE
pgconn_async_exec_prepared(int argc, VALUE *argv, VALUE self)
{
	VALUE rb_pgresult = Qnil;

	pgconn_discard_results( self );
	pgconn_send_query_prepared( argc, argv, self );
	rb_pgresult = pgconn_async_get_last_result( self );

	if ( rb_block_given_p() ) {
		return rb_ensure( rb_yield, rb_pgresult, pg_result_clear, rb_pgresult );
	}
	return rb_pgresult;
}