public IDbQuery <TModel> Select(Func <TModel, object> expression)
{
if (expression == null)
{
throw new ArgumentNullException("expression");
}
var model = expression(new TModel());
var properties = ReflectionHelper.AllProperty(model.GetType(), ReflectionHelper.DefBindingFlags | BindingFlags.DeclaredOnly);
if (properties.Count == 0)
{
throw new NotImplementedException();
}
var modelType = typeof(TModel);
var tableName = modelType.Name;
var tableAliasName = Resolver.ResolveAliasName <TModel>(modelType);
Builder.Dispose();
Builder.Add("SELECT");
Builder.Add(" ");
var index = 0;
foreach (var property in properties)
{
var aliasName = Resolver.ResolveAliasName <TModel>(property.Member);
if (tableName != tableAliasName)
{
Builder.Add(tableAliasName).Add(".");
}
if (aliasName != property.Name)
{
Builder.Add(" AS [").AddColumn(aliasName).Add("]");
}
else
{
Builder.AddColumn(property.Name);
}
if (index != properties.Count - 1)
{
Builder.Add(",");
}
index++;
}
Builder.Add(" ");
Builder.Add("FORM ");
Builder.Add(tableName);
if (tableName != tableAliasName)
{
Builder.Add(" AS ").Add(tableAliasName);
}
return(this);
}
/// <summary>
/// Attempts to parse a schema specification.
/// </summary>
/// <param name="spec">The schema specification string.</param>
/// <returns>A Schema, or null if it failed to parse.</returns>
public static Schema?TryParse(string spec)
{
var map = ColumnTypeMap.Value;
var colSpecs = NewLineRegex.Replace(spec, "").Split(',');
var builder = new Builder();
foreach (var colSpec in colSpecs)
{
var match = ColSpecRegex.Match(colSpec);
if (match.Success)
{
var name = match.Groups["Name"].Value;
var typeName = match.Groups["Type"].Value;
var allowNull = match.Groups["AllowNull"].Success;
if (map.TryGetValue(typeName, out var type))
{
builder.AddColumn(name, type, allowNull);
continue;
}
}
return(null);
}
return(builder.Build());
}
