using System;

using System.Data;

using System.Data.Common;

using Microsoft.Data.Sqlite;

namespace ResultMetadataSample

{

class Program

{

static void Main()

{

var connection = new SqliteConnection("Data Source=:memory:");

connection.Open();

var createCommand = connection.CreateCommand();

createCommand.CommandText =

@"

CREATE TABLE post (

id INTEGER PRIMARY KEY AUTOINCREMENT,

title TEXT NOT NULL UNIQUE,

body TEXT

);

";

createCommand.ExecuteNonQuery();

var queryCommand = connection.CreateCommand();

queryCommand.CommandText =

@"

SELECT id AS post_id,

title,

body,

random() AS random

FROM post;

";

var reader = queryCommand.ExecuteReader();

var schemaTable = reader.GetSchemaTable();

foreach (DataRow column in schemaTable.Rows)

{

if ((bool)column[SchemaTableColumn.IsExpression])

{

Console.Write("(expression) ");

}

else

{

Console.Write($"{column[SchemaTableColumn.BaseColumnName]} ");

}

if ((bool)column[SchemaTableColumn.IsAliased])

{

Console.Write($"AS {column[SchemaTableColumn.ColumnName]} ");

}

Console.Write($"{column["DataTypeName"]} ");

if (column[SchemaTableColumn.AllowDBNull] as bool? == false)

{

Console.Write("NOT NULL ");

}

if (column[SchemaTableColumn.IsKey] as bool? == true)

{

Console.Write("PRIMARY KEY ");

}

if (column[SchemaTableOptionalColumn.IsAutoIncrement] as bool? == true)

{

Console.Write("AUTOINCREMENT ");

}

if (column[SchemaTableColumn.IsUnique] as bool? == true)

{

Console.Write("UNIQUE ");

}

Console.WriteLine();

}

}

}

}