问无法从php调用firebird存储过程

EN

$sqlproc = "select out1 from SP_CLINIC_ID()";

// execute the stored procedure
$stmt = $pdo->prepare($sqlproc);
$stmt->execute();

CREATE PROCEDURE SP_CLINIC_ID
RETURNS(
  MAXID VARCHAR(10))
AS
DECLARE VARIABLE temp_char CHAR(10);
DECLARE VARIABLE temp_id INTEGER;
BEGIN
  /* Procedure body */

  select MAX(CLINIC_id) from COVER_SHEET into MAXID;

  select SUBSTRING(:MAXID from 4 for CHAR_LENGTH(:MAXID)) 
  from rdb$database into temp_char ;

  select cast(:temp_char as NUMERIC) from rdb$database into temp_id;

  temp_id = temp_id + 1;

   if ( temp_id < 10) THEN
  BEGIN
    maxid = 'REG000000'|| temp_id;
  END

  else if ( temp_id < 100) THEN
  begin
  maxid = 'REG00000'|| temp_id;
  end  


  else if ( temp_id < 1000) THEN
  begin
  maxid = 'REG0000'|| temp_id;
  end  

  else if ( temp_id < 10000) THEN
  begin
  maxid = 'REG000'|| temp_id;
  end  

  ELSE if ( temp_id < 100000 ) THEN
  begin
  maxid = 'REG00'|| temp_id;
  end  

  ELSE if ( temp_id < 1000000) THEN
  begin
  maxid = 'REG0'|| temp_id;
  end  

  ELSE if ( temp_id < 10000000) THEN
  begin
  maxid = 'REG'|| temp_id;
  end  

  SUSPEND;
END;