Mit Regex zu extrahieren Tabelle Namen aus einer Datei mit SQL-Abfragen

Ich würde verwenden:

r = new Regex("(from|join)\s+(?<table>\S+)", RegexOptions.IgnoreCase);

sobald man das Match-Objekt "m", müssen Sie den Namen der Tabelle mit

m.Groups["table"].Value

Beispiel:

string line = @"select * from tb_name join tb_name2 ON a=b WHERE x=y";
Regex r = new Regex(@"(from|join)\s+(?<table>\S+)",
         RegexOptions.IgnoreCase|RegexOptions.Compiled);

Match m = r.Match(line);
while (m.Success) {
   Console.WriteLine (m.Groups["table"].Value);
   m = m.NextMatch();
}

es gedruckt wird:
tb_table
tb_table2

können versuchen, diese, aber es funktioniert nicht für alle Arten von Abfragen,

  public void Main()
    {
        //TODO: Add your code here

        string Line = string.Empty;

        using (StreamReader sr = new StreamReader(@"D:\ssis\queryfile.txt"))//reading the filename
        {

            var text = string.Empty;

            do
            {
                //    MessageBox.Show(Line);
                text = Line = sr.ReadToEnd();//storing it in a variable by reading till end

                MessageBox.Show(Line);



            } while ((Line = sr.ReadLine()) != null);



            var text1 = text.Replace("[", string.Empty).Replace("]", string.Empty);//replacing brackets with empty space

            MessageBox.Show(text1);



            Regex r = new Regex(@"(?<=from|join)\s+(?<table>\S+)", RegexOptions.IgnoreCase | RegexOptions.Compiled);//regex for extracting the tablename after from and join

            Match m = r.Match(text1);//creating match object

            MessageBox.Show(m.Groups[1].Value);

            var v = string.Empty;



            while (m.Success)
            {

                v = m.Groups[0].Value;

                m = m.NextMatch();


                StreamWriter wr = new StreamWriter(@"D:\ssis\writefile.txt", true);//writing the match to the file

                var text2 = v.Replace(".", " ,"); //replace the . with , seperated values


                wr.WriteLine(text2);

                sr.Close();
                wr.Close();

            }
        }
    }