Parsing SQL Statement With Irony

Question

I am trying to create a method that converts a regular sql statement to c# objects, So i decided to use Irony to parse the sql statement then i return the statement as an Action that contains the type of the statement and the values of it depending on the type

Here is my non completed code [ Because i got frustrated as i don't know what to do then ]

private List<Action> ParseStatement(string statement)
{
    var parser = new Parser(new SqlGrammar());
    var parsed = parser.Parse(statement);
    var status = parsed.Status;

    while (parsed.Status == ParseTreeStatus.Parsing)
    {
        Task.Yield();
    }

    if (status == ParseTreeStatus.Error)
        throw new ArgumentException("The statement cannot be parsed.");

    ParseTreeNode parsedStmt = parsed.Root.ChildNodes[0];

    switch (parsedStmt.Term.Name)
    {
        case "insertStmt":
            var table = parsedStmt.ChildNodes.Find(x => x.Term.Name == "Id").ChildNodes[0].Token.ValueString;
            var valuesCount =
                parsedStmt.ChildNodes.Find(x => x.Term.Name == "insertData").ChildNodes.Find(
                    x => x.Term.Name == "exprList").ChildNodes.Count;
            var values = parsedStmt.ChildNodes.Find(x => x.Term.Name == "insertData").ChildNodes.Find(
                    x => x.Term.Name == "exprList").ChildNodes;
            foreach (var value in values)
            {
                string type = value.Token.Terminal.Name;
            }
            break;
    }

    return null;
}

private Type ParseType(string type)
{
    switch (type)
    {
        case "number":
            return typeof (int);
        case "string":
            return typeof (string);
    }

    return null;
}

So the Question Here is : How could i make use of Irony to convert a string SQL Statement to a c# objects ?

Here is an example of what i want to achieve :

INSERT INTO Persons VALUES (4,'Nilsen', 'Johan', 'Bakken 2', 'Stavanger')

And get it converted to

return new Action<string type, string table, int val1, string val2, string val3, string val4, string val5>;

Dynamically depending on what the method have read from the statement.

I hope i have well explained my idea so you can help me guys, And if there is something unclear please tell me and i will try to explain it.

Answer 1

I was trying to parse SQL with Irony as well. I gave up because the sample SQL parser in Irony don't handle: CTEs, Order by column number, half the special statements like

SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED

While I had a great time learning about Irony, I don't have the coding chops to implement all the aforementioned parts correctly.

I ended up using the Microsoft-provided SQL parsing library. Sample code for LINQPad 5 below:

// Add a reference to
// C:\Program Files (x86)\Microsoft SQL Server\130\SDK\Assemblies\
//   Microsoft.SqlServer.TransactSql.ScriptDom.dll
// 
// https://blogs.msdn.microsoft.com/gertd/2008/08/21/getting-to-the-crown-jewels/

public void Main()
{
    var sqlFilePath = @"C:\Users\Colin\Documents\Vonigo\database-scripts\Client\Estimate\spClient_EstimateAddNew.sql";
    bool fQuotedIdenfifiers = false;
    var parser = new TSql100Parser(fQuotedIdenfifiers);

    string inputScript = File.ReadAllText(sqlFilePath);
    IList<ParseError> errors;
    using (StringReader sr = new StringReader(inputScript))
    {
        var fragment = parser.Parse(sr, out errors);
        fragment.Dump();
    }
}

Answer 2

If you are not doing this as a fun exercise I would recommend using Linq to SQL to generate your stub classes or Entity Framework as Drunken Code Monkey mentioned in the comments.

Here's a good article to get you started: Generating EF code from existing DB