CreateParser.scala

import scala.util.parsing.combinator._

/**
 * expr :: CREATE TABLE tbl_name ( create_definition,...)
 * 
 * create_definition:
 *   col_name column_definition
 * 
 * column_definition:
 *   data_type
 * 
 * data_type: string
 */
class CreateParser extends JavaTokenParsers {

  def colOption:Parser[Number] = 
    "(" ~ decimalNumber ~ ")" ^^ { case _~num~_ => num.toInt }

  def column:Parser[Column] = ident ~ ident ~ opt( colOption ) ^^ { 
      case name~stype~o => Column(name,stype,o) 
  }

  def columns:Parser[ List[Column] ] = 
    "(" ~> repsep(column,",") <~ ")" ~ ";" ^^ { case l => l }

  def create:Parser[Create] = "create" ~ "table" ~ ident ~ columns ^^ { 
    case _~_~name~cs => Create(name,cs) 
  }

  case class Create( name:String, cols:List[Column] ) {
    def gen:String = name +"->"+ cols.map( _.gen )
  }
  case class Column( name:String, sql_type:String, option:Option[Any] ) {
    def gen:String = name + ":" + sql_type
  }
}

object CreateTest extends CreateParser {
  def main(args:Array[String]) {
   p("""
   CREATE  table simple (
     id integer(10),
     name varchar(255)
   ) ;
   """)
  }

  def p( sql:String ) {
    val s = sql.toLowerCase
    println( parseAll(create, s) )
    println( parseAll(create, s).get.gen )
  }

}