C#——使用Odbc操作Access數據庫 (.NET Core)

若項目是基於 .NET Framework，請使用 OleDb，詳情參閱 C#——使用OleDb操作Access數據庫(.NET Framework)

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.Odbc;
using System.Linq;

namespace SomeNameSpace
{
	/// <summary>
    /// 操作Access數據庫(.NET Core)
    /// </summary>
    public class AccessHelper
    {
        // 定義連接字符串
        public static string AccessFileName { get; set; }
        public static readonly string ConnString =
            @"Driver={Microsoft Access Driver (*.mdb, *.accdb)};DBQ=" +
            AppDomain.CurrentDomain.BaseDirectory +
            @$"Files\{AccessFileName}.accdb;";

        /// <summary>
        /// 獲取數據庫中所有表名
        /// </summary>
        /// <returns></returns>
        public static List<string> GetAllTableNames()
        {
            List<string> result = new List<string>();
            using (OdbcConnection conn = new OdbcConnection(ConnString))
            {
                try
                {
                    conn.Open();
                    DataTable tbs = conn.GetSchema("tables");
                    foreach (DataRow dr in tbs.AsEnumerable().Where(x => x["TABLE_TYPE"].ToString() == "TABLE"))
                    {
                        result.Add(dr["TABLE_NAME"].ToString());
                    }
                }
                catch (Exception e)
                {
                    System.Windows.MessageBox.Show(e.Message);
                }
            }
            return result;
        }

        /// <summary>
        /// 更新數據庫中表，實際上可以說是替換,若表不存在將自動創建
        /// </summary>
        /// <param name="dt">表</param>
        /// <param name="tableName">表名</param>
        public static void UpdateDBTable(System.Data.DataTable dt, string tableName)
        {
            if (!IsTableExist(tableName))
            {
                CreatDBTable(dt, tableName);
            }
            using OdbcConnection conn = new OdbcConnection(ConnString);
            try
            {
                conn.Open();
                string sql = $"delete * from {tableName}";
                OdbcCommand odc = new OdbcCommand(sql, conn);
                odc.ExecuteNonQuery();
                for (int i = 0; i < dt.Rows.Count; i++)
                {
                    string add_sql = "";
                    if (dt.Columns.Contains("ID"))
                    {
                        add_sql = $"Insert Into {tableName} Values('{i + 1}'";
                    }
                    else
                    {
                        add_sql = $"Insert Into {tableName} Values('{dt.Rows[i].ItemArray[0]}'";
                    }
                    for (int j = 1; j < dt.Columns.Count; j++)
                    {
                        add_sql += $",'{dt.Rows[i].ItemArray[j]}'";
                    }
                    add_sql += ")";
                    odc.CommandText = add_sql;
                    odc.Connection = conn;
                    odc.ExecuteNonQuery();
                }
                odc.Dispose();
            }
            catch (Exception e)
            {
                if (e.Message.Contains("查詢值的數目與目標字段中的數目不同"))
                {
                    DeleteDBTable(tableName);
                    UpdateDBTable(dt, tableName);
                }
                else
                {
                    System.Windows.MessageBox.Show(e.Message);
                }
            }
        }

        /// <summary>
        /// 新建數據表
        /// </summary>
        /// <param name="dt">表</param>
        /// <param name="tableName">表名</param>
        public static bool CreatDBTable(System.Data.DataTable dt, string tableName)
        {
            if (IsTableExist(tableName))
            {
                System.Windows.MessageBox.Show("表已存在，請檢查名稱！");
                return false;
            }
            else
            {
                try
                {
                    using OdbcConnection conn = new OdbcConnection(ConnString);
                    conn.Open();
                    //構建字段組合
                    string StableColumn = "";
                    for (int i = 0; i < dt.Columns.Count; i++)
                    {
                        Type t = dt.Columns[i].DataType;
                        if (t.Name == "String")
                        {
                            StableColumn += string.Format("{0} varchar", dt.Columns[i].ColumnName);
                        }
                        else if (t.Name == "Int32" || t.Name == "Double")
                        {
                            StableColumn += string.Format("{0} int", dt.Columns[i].ColumnName);
                        }
                        if (i != dt.Columns.Count - 1)
                        {
                            StableColumn += ",";
                        }
                    }
                    string sql = "";
                    if (StableColumn.Contains("ID int"))
                    {
                        StableColumn = StableColumn.Replace("ID int,", "");
                        sql = $"create table {tableName}(ID autoincrement primary key,{StableColumn}";
                    }
                    else
                    {
                        sql = $"create table {tableName}({StableColumn})";
                    }
                    OdbcCommand odc = new OdbcCommand(sql, conn);
                    odc.ExecuteNonQuery();
                    odc.Dispose();
                    return true;
                }
                catch (Exception e)
                {
                    System.Windows.MessageBox.Show(e.Message);
                    return false;
                }
            }
        }

        /// <summary>
        /// 刪除數據庫中表
        /// </summary>
        /// <param name="tableName"></param>
        /// <returns></returns>
        public static bool DeleteDBTable(string tableName)
        {
            if (IsTableExist(tableName))
            {
                using OdbcConnection conn = new OdbcConnection(ConnString);
                try
                {
                    conn.Open();
                    string sql = $"drop table {tableName}";
                    OdbcCommand odc = new OdbcCommand(sql, conn);
                    odc.ExecuteNonQuery();
                    odc.Dispose();
                    return true;
                }
                catch (Exception e)
                {
                    System.Windows.MessageBox.Show(e.Message);
                    return false;
                }
            }
            else { return false; }
        }

        /// <summary>
        /// 查詢表是否存在
        /// </summary>
        /// <param name="tableName"></param>
        /// <returns></returns>
        public static bool IsTableExist(string tableName)
        {
            using OdbcConnection conn = new OdbcConnection(ConnString);
            try
            {
                conn.Open();
                string sql = $"select * from {tableName}";
                OdbcCommand odc = new OdbcCommand(sql, conn);
                odc.ExecuteNonQuery();
                odc.Dispose();
                return true;
            }
            catch (Exception)
            {
                System.Windows.MessageBox.Show($"數據庫中不存在表: {tableName}");
                return false;
            }
        }

        /// <summary>
        /// 獲取數據庫中表
        /// </summary>
        /// <param name="tableName"></param>
        /// <returns></returns>
        public static DataTable GetDBTable(string tableName)
        {
            if (!IsTableExist(tableName))
            {
                return null;
            }
            using OdbcConnection conn = new OdbcConnection(ConnString);
            try
            {
                conn.Open();
                string sql = $"select * from {tableName}";
                DataTable dt = new DataTable();
                OdbcDataAdapter oda = new OdbcDataAdapter(sql, conn);
                oda.Fill(dt);
                oda.Dispose();
                dt.TableName = tableName;
                return dt;
            }
            catch (Exception e)
            {
                System.Windows.MessageBox.Show(e.Message);
                return null;
            }
        }
    }
}