Sqlite CodeFirst的初级实现

示例实体:

using System;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using System.Diagnostics.CodeAnalysis;
using Honeysuckle.Domain.Entities;

namespace Chagoi.Pos.Core.Entity.Goods
{
    [Table("a2")]
    [SuppressMessage("ReSharper", "InconsistentNaming")]
    public class GoodsInfo : Entity<int>
    {
        [Column("c1")]
        public string Name { get; set; }

        /// <summary>
        /// 商品条码
        /// </summary>
        [Column("c2")]
        [StringLength()]
        [Index]
        public string goods_barcode { get; set; }

        /// <summary>
        /// 简称
        /// </summary>
        [Column("c3")]
        [StringLength()]
        [Index("fdafd")]
        public string goods_short_name { get; set; }

        [Column("c4")]
        [StringLength()]
        [Required]
        public string hello { get; set; }

        [Column("c5")]
        public DateTime UpdateTime { get; set; }
    }

}

生成代码:

using Castle.Core.Logging;
using Chagoi.Pos.Core.Entity.Device;
using Chagoi.Pos.Core.Entity.Goods;
using Chagoi.Pos.Core.Entity.Order;
using Chagoi.Pos.Core.Entity.Pay;
using Chagoi.Pos.Core.Entity.Users;
using Honeysuckle.Dependency;
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using System.Configuration;
using System.Data;
using System.Data.SQLite;
using System.Diagnostics;
using System.Linq;
using System.Text;

namespace Chagoi.Pos.EntityFramework.Seed
{
    public static class SeedHelper
    {
        private static readonly string DbPath;
        private static ILogger _logger;

        static SeedHelper()
        {
            DbPath = ConfigurationManager.ConnectionStrings["Default"].ConnectionString;
        }

        public static void SeedHostDb(IIocResolver iocResolver, ILogger logger)
        {
            _logger = logger;
            SeedHostDb();
        }

        private static void SeedHostDb()
        {
            var tobeCreateTables = new List<Type>()
            {
                typeof(IotDevice),

                typeof(GoodsInfo),
                typeof(GoodsCategory),
                typeof(GoodsBrand),

                typeof(AlipayParameter),
                typeof(WxpayParameter),

                typeof(AppUser),
                typeof(Order)
            };

            _logger.Info("#region 开始执行数据库的创建或结构调整");

            var stopwatch = new Stopwatch();
            stopwatch.Start();

            using (var connection = new SQLiteConnection(DbPath))
            {
                connection.Open();

                using (var transaction = connection.BeginTransaction())
                {
                    try
                    {
                        foreach (var entity in tobeCreateTables)
                        {
                            //表名称,这里使用混淆表明,要求必须输入
                            var tableAttribute = entity.GetCustomAttributes(typeof(TableAttribute), true).FirstOrDefault();
                            if (null == tableAttribute)
                            {
                                throw new ArgumentNullException(nameof(TableAttribute));
                            }
                            var tableName = ((TableAttribute)tableAttribute).Name;

                            //填充数据库中标的原始结构
                            var tableStructureCommandText = $"PRAGMA table_info(\"{tableName}\");";
                            var sqLiteCommand = new SQLiteCommand(connection) { CommandText = tableStructureCommandText };
                            var sQLiteDataAdapter = new SQLiteDataAdapter(sqLiteCommand);
                            var tableStructure = new DataTable(tableName);
                            sQLiteDataAdapter.Fill(tableStructure);

                            var hasTable = tableStructure.Rows.Count > ;
                            if (!hasTable)
                            {
                                _logger.Info($"表{tableName}不存在,开始执行创建过程...");

                                //执行创建表的SQL语句
                                var createTableSql = GenerateCreateTableCommandText(entity, tableName);
                                sqLiteCommand.CommandText = createTableSql;
                                _logger.Debug(sqLiteCommand.CommandText);
                                sqLiteCommand.ExecuteNonQuery();
                                _logger.Info($"表{tableName}的创建语句已执行.");
                            }
                            else
                            {
                                _logger.Info($"表{tableName}已经存在,开始执行差异对比过程...");
                                var updateTableSql = GenerateUpdateTableCommandText(entity, tableStructure);
                                if (string.IsNullOrEmpty(updateTableSql))
                                {
                                    _logger.Info($"表{tableName}结构无差异,无需调整.");
                                    continue;
                                }
                                sqLiteCommand.CommandText = updateTableSql;
                                _logger.Debug(sqLiteCommand.CommandText);
                                var nonQuery = sqLiteCommand.ExecuteNonQuery();
                                _logger.Info($"表{tableName}的调整语句已执行,返回结果:{nonQuery}");
                            }
                        }

                        transaction.Commit();
                    }
                    catch (Exception ex)
                    {
                        _logger.Error("执行数据库的创建或结构调整过程发生异常",ex);
                        transaction.Rollback();
                    }
                }

                connection.Dispose();
            }

            stopwatch.Stop();

            var elapsedMilliseconds = stopwatch.ElapsedMilliseconds;

            _logger.Info($"#endregion 执行数据库的创建或结构调整过程完毕,耗时{elapsedMilliseconds}毫秒");
        }

        /// <summary>
        /// 生成创建表的sql命令,包含索引的创建
        /// </summary>
        /// <param name="entityType">实体类型</param>
        /// <param name="tableName">表的名称</param>
        /// <returns></returns>
        private static string GenerateCreateTableCommandText(Type entityType, string tableName)
        {
            var properties = entityType.GetProperties();

            //索引创建语句,根据实体的Index特性来生成
            var createTableIndexCommandTexts = new List<string>();

            var createTableCommandText = $"CREATE TABLE \"{tableName}\" (";
            foreach (var property in properties)
            {
                //列名,优先取特性名称
                var columnName = GetColumnName(property);

                //是否可空
                var notNull = IsNotNull(property);

                //字段类型
                var dbType = GetDbType(property);

                createTableCommandText += $"\"{columnName}\" {dbType} {notNull},";

                //处理索引
                var indexAttributeObj = property.GetCustomAttributes(typeof(IndexAttribute), true).FirstOrDefault();
                if (null != indexAttributeObj)
                {
                    var indexAttribute = ((IndexAttribute)indexAttributeObj);

                    //是否是唯一索引
                    var unique = indexAttribute.IsUnique ? "UNIQUE" : "";

                    //索引名称
                    var indexName = string.IsNullOrEmpty(indexAttribute.Name) ? $"Index_{columnName}" : indexAttribute.Name;

                    //创建索引的语句
                    var indexSql = $"CREATE {unique} INDEX \"{indexName}\" ON \"{tableName}\"(\"{columnName}\" ASC); ";
                    createTableIndexCommandTexts.Add(indexSql);
                }
            }
            createTableCommandText += "PRIMARY KEY (\"Id\" ASC)";
            createTableCommandText += ");";

            var allCommandText = new StringBuilder(createTableCommandText);
            foreach (var createTableIndexCommandText in createTableIndexCommandTexts)
            {
                allCommandText.Append(createTableIndexCommandText);
            }
            return allCommandText.ToString();
        }

        /// <summary>
        /// 生成更新表的sql命令,只支持新增列
        /// 不支持添加索引列,不支持删除列
        /// 新增的列必须允许为空
        /// </summary>
        /// <param name="entityType">实体类型</param>
        /// <param name="dataTable">数据中的表结构</param>
        /// <returns></returns>
        private static string GenerateUpdateTableCommandText(Type entityType, DataTable dataTable)
        {
            var properties = entityType.GetProperties();
            var alreadyCreatedColumnNames = dataTable.AsEnumerable().Select(t => t.Field<string>("name").ToString()).ToArray();

            var addColumnCommandTexts = new List<string>();
            foreach (var property in properties)
            {
                var colName = GetColumnName(property);
                var alreadyCreated = alreadyCreatedColumnNames.Any(m => m == colName);
                if (!alreadyCreated)
                {

                    var dbType = GetDbType(property);
                    var addColumnCommandText = $"ALTER  TABLE   \"{dataTable.TableName}\" ADD COLUMN  \"{colName}\" {dbType} NULL;";
                    addColumnCommandTexts.Add(addColumnCommandText);
                }
            }

            var allCommandText = new StringBuilder();
            foreach (var addColumnCommand in addColumnCommandTexts)
            {
                allCommandText.Append(addColumnCommand);
            }
            return allCommandText.ToString();
        }

        #region 基础函数

        /// <summary>
        /// 获取数据类型
        /// </summary>
        /// <param name="property"></param>
        /// <returns></returns>
        private static string GetDbType(System.Reflection.PropertyInfo property)
        {
            string dbType;
            if (property.PropertyType.FullName != null)
            {
                var propertyTypeFullName = property.PropertyType.FullName.ToUpper();
                switch (propertyTypeFullName)
                {
                    case "SYSTEM.BOOLEAN":
                        dbType = "BOOLEAN";
                        break;
                    case "SYSTEM.INT32":
                    case "SYSTEM.INT64":
                        dbType = "INTEGER";
                        break;
                    case "SYSTEM.STRING":
                        //是否标记了最大长度
                        var stringLengthAttributeObj = property.GetCustomAttributes(typeof(StringLengthAttribute), true).FirstOrDefault();
                        if (stringLengthAttributeObj != null)
                        {
                            var length = ((StringLengthAttribute)stringLengthAttributeObj).MaximumLength;
                            dbType = $"VARCHAR({length})";
                        }
                        else
                        {
                            dbType = "TEXT";
                        }
                        break;
                    case "SYSTEM.DATETIME":
                        dbType = "DATETIME";
                        break;
                    default:
                        throw new ArgumentOutOfRangeException(nameof(propertyTypeFullName));
                }
            }
            else
            {
                throw new ArgumentNullException(nameof(property.PropertyType.FullName));
            }

            return dbType;
        }

        /// <summary>
        /// 字段是否可用
        /// </summary>
        /// <param name="property"></param>
        /// <returns></returns>
        private static string IsNotNull(System.Reflection.PropertyInfo property)
        {
            var hasRequiredAttribute = property.GetCustomAttributes(typeof(RequiredAttribute), true).Length > ;
            var notNull = hasRequiredAttribute ? "NOT NULL" : "";
            if (property.Name.ToUpper() == "ID")  //ID始终不能为空
            {
                notNull = "NOT NULL";
            }

            return notNull;
        }

        /// <summary>
        /// 获取列名
        /// </summary>
        /// <param name="property"></param>
        /// <returns></returns>
        private static string GetColumnName(System.Reflection.PropertyInfo property)
        {
            var columnName = property.Name;
            var columnAttributeObj = property.GetCustomAttributes(typeof(ColumnAttribute), true).FirstOrDefault();
            if (null != columnAttributeObj)
            {
                columnName = ((ColumnAttribute)columnAttributeObj).Name;
            }

            return columnName;
        }

        #endregion
    }
}