DeleteParser.cs

using System;
using Waher.Script.Model;
 
namespace Waher.Script.Persistence.SQL.Parsers
{
    public class DeleteParser : IKeyWord
    {
        public DeleteParser()
        {
        }
 
        public string KeyWord => "DELETE";
 
        public string[] Aliases => null;
 
        public string[] InternalKeywords => new string[] 
        { 
            "LAZY", 
            "FROM", 
            "WHERE" 
        };
 
        public bool TryParse(ScriptParser Parser, out ScriptNode Result)
        {
            Result = null;
 
            string s = Parser.NextToken().ToUpper();
            bool Lazy = s == "LAZY";
 
            if (Lazy)
                s = Parser.NextToken().ToUpper();
 
            if (s != "FROM")
                return false;
 
            if (!SelectParser.TryParseSources(Parser, out SourceDefinition Source))
                return false;
 
            ScriptNode Where = null;
 
            s = Parser.PeekNextToken().ToUpper();
            if (s == "WHERE")
            {
                Parser.NextToken();
                Where = Parser.ParseOrs();
            }
 
            Result = new Delete(Source, Where, Lazy, Parser.Start, Parser.Length, Parser.Expression);
 
            return true;
        }
 
    }
}