C# .NET 7 使用ADO.NET+SQLite3，制作SQLiteHelper

.NET项目使用SQLite3，可以在Nuget里安装Microsoft.Data.Sqlite或System.Data.SQLite，无论哪个，在SQLiteHelper写上SQLite的链接字符串，在SqliteConnection链接时，会自动生成生成数据库文件在项目根目录。

下面是我之前制作SQLiteHelper的样本代码，记录下，以后好用。.

using System.Data.SqlClient;using System.Data;using System.Data.SQLite;namespace Test.Common{    /// <summary>    /// 数据库的通用访问代码 抽象类    /// 不允许实例化，在应用时直接调用即可    /// </summary>    public abstract class SQLiteHelper    {        public static readonly string connString = "Data Source=Database.sqlite;Version=3;";        public static int ExecuteNonQuery(string sql)        {            using SQLiteConnection conn = new SQLiteConnection(connString);            SQLiteCommand cmd = new SQLiteCommand(sql, conn);            if (conn.State != ConnectionState.Open) conn.Open();            int num = cmd.ExecuteNonQuery();            conn.Close();            return num;        }        public static DataTable GetDataTable(string sql)        {            using SQLiteConnection conn = new SQLiteConnection(connString);            if (conn.State != ConnectionState.Open) conn.Open();            SQLiteDataAdapter dsTmp = new SQLiteDataAdapter(sql, conn);            DataTable dt = new DataTable();            dsTmp.Fill(dt);            conn.Close();            return dt;        }        public static string ExecuteScalar(string sql)        {            using SQLiteConnection conn = new SQLiteConnection(connString);            SQLiteCommand cmd = new SQLiteCommand(sql, conn);            if (conn.State != ConnectionState.Open) conn.Open();            string result = cmd.ExecuteScalar().ToString();            conn.Close();            return result;        }    }}