XDatabase usage examples

XDatabaseExamples.cs

// https://github.com/kungfux/xdatabase

using System;
using XDatabase;

namespace Examples
{
    public class Test
    {
        private const string _connectionString = "Data Source=db.sqlite;";
        // Create an instance that points to a proper database type
        public void Init()
        {
            var xQuery1 = new XQuerySqlite();
            var xQuery2 = new XQueryMySql();
            var xQuery3 = new XQueryOleDb();
        }

        // Select data as Table, Column, Row or a single Cell
        public void SelectData()
        {
            var xQuery = new XQuerySqlite(_connectionString);
            var selectTable = xQuery.SelectTable("select * from table;");
            var selectColumn = xQuery.SelectColumn("select username from users;");
            var selectRow = xQuery.SelectRow("select * from users limit 1;");
            var selectCellAsString = xQuery.SelectCellAs<string>("select username from users where login='admin';");
                // Administrator
            var selectCellAsNum = xQuery.SelectCellAs<long>("select failedAttempts from users where login='admin';");
                // 3
            var selectCellAsDouble = xQuery.SelectCellAs<double>("select weight from users where login='admin';");
                // 1.23
        }

        // Use arguments in sql
        public void Arguments()
        {
            var xQuery = new XQuerySqlite(_connectionString);
            var result = xQuery.SelectTable("select * from users where login=@login;",
                xQuery.AddParameter("@login", "admin"));
        }

        // Create, insert, update and delete
        public void ChangeData()
        {
            var xQuery = new XQuerySqlite(_connectionString);
            xQuery.Create("create table users (id int primary key autoincrement, login varchar(255));");
            xQuery.Insert("insert into users (login) values ('admin');");
            xQuery.Update("update users set login='admin' where login='admina';");
            xQuery.Delete("delete from users where login='admin';");
        }

        // Check result of operation
        public void Result()
        {
            var xQuery = new XQuerySqlite(_connectionString);
            var result = xQuery.Update("update users set username=@username where login=@login",
                xQuery.AddParameter("@username", "Administrator"),
                xQuery.AddParameter("@login", "admin")
                );
            if (result >= XResult.ChangesApplied)
                Console.WriteLine("Updated successfully!");
        }

        // Transactions
        public void Transaction()
        {
            var xQuery = new XQuerySqlite(_connectionString);
            var isInterrupted = false;
            xQuery.BeginTransaction();
            for (var i = 0; i < 100; i++)
            {
                var result = xQuery.Insert($"insert into users (username) values ('test-{i}');");
                if (!result)
                {
                    isInterrupted = false;
                    xQuery.RollbackTransaction();
                    break;
                }
            }
            if (!isInterrupted)
            {
                xQuery.CommitTransaction();
            }
        }

        // Work with binary data and images
        public void Binary()
        {
            var xQuery = new XQuerySqlite(_connectionString);
            // insert binary data into a cell
            var binData = new byte[] { 1, 0, 1, 1, 0, 1, 1, 0 };
            xQuery.InsertBinaryIntoCell(binData, "update users set photo=@photo where login='admin';", "@photo");
            // select binary data from cell
            var binDataNew = xQuery.SelectCellAs<byte[]>("select photo from users where login='admin';");
            // insert file into a cell
            var image = "C:\\photo.png";
            xQuery.InsertFileIntoCell(image, "update users set document=@doc where login='admin';", "@doc");
            // select image from database
            var imageNew = xQuery.SelectBinaryAsImage("select photo from users where login='admin';");
            // select binary and save
            xQuery.SelectBinaryAndSave("D:\image.png", "select photo from users where login='admin';");
        }
    }
}