Question

是否有一个用于SQLite的MigrationSqlGenerator与实体框架一起使用？我只从devart找到了一个商业广告。

找不到提供者'System.Data.SQLite'的MigrationSqlGenerator。使用目标迁移配置中的SetSqlGenerator方法注册其他SQL生成器的类。

这就是我所做的：http://msdn.microsoft.com/en-gb/data/jj591621

Answer 1

据我所知，我不认为有任何免费的。

如果您不关心Devart商业广告dotConnect for SQLite - 您可以尝试自己实施一个 - 它可能不是那么简单，但您可以使用EF源代码（对于EF6，但这些部分相当类似的我会说。） http://entityframework.codeplex.com/

如果您查看SqlCeMigrationSqlGenerator源代码（其他来源，我在官方网站上找不到，但您可以下载并查看）

......你会发现发电机相对简单。当然，Ce使用标准的Sql客户端作为底层生成器。

SQLite需要更多工作，但可能不会那么难。

此外，类似的事情来自EF的知名来源 - Can we use EF migrations with MySql

不要'对我大喊':)我知道这不是你想要的 - 但我认为这是唯一的选择。

<小时/> http://entityframework.codeplex.com/
SqlCeMigrationSqlGenerator
Can we use EF migrations with MySql

Answer 2

虽然帖子已经开放了很长时间，但我会根据我们的朋友NSGaga出现的内容发布我要做的事情。

我设法根据为SQLCE开发的内容创建了一个类“MigrationSqLiteGenerator”。该类的代码太大，更多可以在我的博客上下载。

在Google云端硬盘上： https://drive.google.com/file/d/0B-NCqWnMQpBrQjkxMkxnVlRzb00/view?usp=sharing

本课程只有基础知识，而且是改进的起点。

22.Mar.2017编辑@ shiva ：这是内联代码，因此如果Google云端硬盘链接再次中断，您仍然可以访问该代码。刚发现SO在答案帖子中有30,000字符限制，所以我不得不删除代码中的注释。它超过32,000字符并带有注释：）

//           *-----------------------------------------------------------------*
//           *                                                                 *
//           *    CRIADO POR...: Julio C. Borges.                              *
//           *    DATA.........: 19/07/2013.                                   *
//           *    MOTIVO.......:                                               *
//           *                                                                 *
//           *-----------------------------------------------------------------*

using System;
using System.CodeDom.Compiler;
using System.Collections.Generic;
using System.Data.Common;
using System.Data.Entity.Migrations.Model;
using System.Data.Entity.Migrations.Sql;
using System.Data.Metadata.Edm;
using System.Data.SQLite;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Text;

namespace ICM_Conexao.SqLite.Classes
{
    /// <sumary>
    /// MigrationSqLiteGenerator 
    /// </sumary>
    public class MigrationSqLiteGenerator : MigrationSqlGenerator
    {
        #region Constantes

        private const string pstrDefaultDateTime = "yyyy-MM-dd hh:mm:ss";
        private const int pintDefaultStringMaxLength = 255;
        private const int pintDefaultPrecisaoNumerica = 10;
        private const byte pbytDefaultPrecisaoTempo = 7;
        private const byte pintDefaultEscala = 0;
        //private const string pstrNomeTabelaMigration = "__MigrationHistory"; 

        #endregion

        #region Instancias

        private DbProviderManifest pprovProviderManifest;
        private List<MigrationStatement> plstComandos;
        private bool pblnGerouPrimaryKey;

        #endregion

        #region Método de Geração sobrescrito de MigratioSqlGenerator

        public override IEnumerable<MigrationStatement> Generate(
            IEnumerable<MigrationOperation> lstOperacoesMigrations, string strManifestoProvider)
        {
            plstComandos = new List<MigrationStatement>();

            InicializaServicosProvider(strManifestoProvider);
            GeraComandos(lstOperacoesMigrations);

            return plstComandos;
        }

        #endregion

        #region Métodos de geração dos comandos

        protected virtual void Generate(CreateTableOperation opeCriacaoTabela)
        {
            // Preferencialmente não iremos gerar a tabela de dados do Migration
            if (opeCriacaoTabela.Name.Contains("MigrationHistory"))
                return;

            using (var ltextWriter = TextWriter())
            {
                GeraComandoCriacaoTabela(opeCriacaoTabela, ltextWriter);

                ComandoSQL(ltextWriter);
            }
        }

        protected virtual void Generate(AddForeignKeyOperation opeChaveEstrangeira)
        {
            // Inicialmente não havera a criação de chave estrangeira
        }

         protected virtual void Generate(DropForeignKeyOperation dropForeignKeyOperation)
        {
            // Inicalmente não haverá a criação de chave estrangeira
        }

        protected virtual void Generate(CreateIndexOperation opeCriacaoIndex)
        {
            using (var ltextWriter = TextWriter())
            {
                ltextWriter.Write("CREATE ");

                if (opeCriacaoIndex.IsUnique)
                    ltextWriter.Write(" UNIQUE ");

                ltextWriter.Write("INDEX ");
                ltextWriter.Write(opeCriacaoIndex.Name);
                ltextWriter.Write(" ON ");
                ltextWriter.Write(RemoveDBO(opeCriacaoIndex.Table));
                ltextWriter.Write("(");

                for (int lintCount = 0; lintCount < opeCriacaoIndex.Columns.Count; lintCount++)
                {
                    var lstrDadosColuna = opeCriacaoIndex.Columns[lintCount];

                    ltextWriter.Write(lstrDadosColuna);

                    if (lintCount < opeCriacaoIndex.Columns.Count - 1)
                        ltextWriter.WriteLine(",");
                }

                ltextWriter.Write(")");

                ComandoSQL(ltextWriter);
            }
        }

         protected virtual void Generate(DropIndexOperation opeDropIndex)
        {
            using (var ltextWriter = TextWriter())
            {
                ltextWriter.Write("DROP INDEX ");
                ltextWriter.Write(opeDropIndex.Name);

                ComandoSQL(ltextWriter);
            }
        }

         protected virtual void Generate(AddPrimaryKeyOperation opeAdicionaPrimaryKey)
        {
            using (var ltextWriter = TextWriter())
            {
                ltextWriter.Write("ALTER TABLE ");
                ltextWriter.Write(RemoveDBO(opeAdicionaPrimaryKey.Table));
                ltextWriter.Write(" ADD CONSTRAINT ");
                ltextWriter.Write(opeAdicionaPrimaryKey.Name);
                ltextWriter.Write(" PRIMARY KEY ");
                ltextWriter.Write("(");

                for (int li = 0; li < opeAdicionaPrimaryKey.Columns.Count; li++)
                {
                    var lstrDadosColuna = opeAdicionaPrimaryKey.Columns[li];

                    ltextWriter.Write(lstrDadosColuna);

                    if (li < opeAdicionaPrimaryKey.Columns.Count - 1)
                        ltextWriter.WriteLine(",");
                }

                ltextWriter.Write(")");

                ComandoSQL(ltextWriter);
            }
        }

        protected virtual void Generate(DropPrimaryKeyOperation opeDropPrimaryKey)
        {
            using (var ltextWriter = TextWriter())
            {
                ltextWriter.Write("ALTER TABLE ");
                ltextWriter.Write(RemoveDBO(opeDropPrimaryKey.Table));
                ltextWriter.Write(" DROP CONSTRAINT ");
                ltextWriter.Write(opeDropPrimaryKey.Name);

                ComandoSQL(ltextWriter);
            }
        }

        protected virtual void Generate(AddColumnOperation opeAdicionaColuna)
        {
            using (var ltextWriter = TextWriter())
            {
                ltextWriter.Write("ALTER TABLE ");
                ltextWriter.Write(RemoveDBO(opeAdicionaColuna.Table));
                ltextWriter.Write(" ADD ");

                var lcmColuna = opeAdicionaColuna.Column;

                Generate(lcmColuna, ltextWriter, null);

                if ((lcmColuna.IsNullable != null)
                    && !lcmColuna.IsNullable.Value
                    && (lcmColuna.DefaultValue == null)
                    && (string.IsNullOrWhiteSpace(lcmColuna.DefaultValueSql))
                    && !lcmColuna.IsIdentity
                    && !lcmColuna.IsTimestamp
                    && !lcmColuna.StoreType.Equals("rowversion", StringComparison.InvariantCultureIgnoreCase)
                    && !lcmColuna.StoreType.Equals("timestamp", StringComparison.InvariantCultureIgnoreCase))
                {
                    ltextWriter.Write(" DEFAULT ");

                    if (lcmColuna.Type == PrimitiveTypeKind.DateTime)
                    {
                        ltextWriter.Write(Generate(DateTime.Parse("1900-01-01 00:00:00", CultureInfo.InvariantCulture)));
                    }
                    else
                    {
                        ltextWriter.Write(Generate((dynamic)lcmColuna.ClrDefaultValue));
                    }
                }

                ComandoSQL(ltextWriter);
            }
        }

         protected virtual void Generate(DropColumnOperation opeRemoveColuna)
        {
            using (var ltextWriter = TextWriter())
            {
                ltextWriter.Write("ALTER TABLE ");
                ltextWriter.Write(RemoveDBO(opeRemoveColuna.Table));
                ltextWriter.Write(" DROP COLUMN ");
                ltextWriter.Write(opeRemoveColuna.Name);

                ComandoSQL(ltextWriter);
            }
        }

        protected virtual void Generate(AlterColumnOperation opeAlteraColuna)
        {
            var lcmColuna = opeAlteraColuna.Column;

            using (var ltextWriter = TextWriter())
            {
                ltextWriter.Write("ALTER TABLE ");
                ltextWriter.Write(RemoveDBO(opeAlteraColuna.Table));
                ltextWriter.Write(" ALTER COLUMN ");
                ltextWriter.Write(lcmColuna.Name);
                ltextWriter.Write(" ");
                ltextWriter.Write(ConstruirTipoColuna(lcmColuna));

                if ((lcmColuna.IsNullable != null)
                    && !lcmColuna.IsNullable.Value)
                {
                    ltextWriter.Write(" NOT NULL");
                }

                ComandoSQL(ltextWriter);
            }

            if ((lcmColuna.DefaultValue == null) && string.IsNullOrWhiteSpace(lcmColuna.DefaultValueSql))
                return;

            using (var ltextWriter = TextWriter())
            {
                ltextWriter.Write("ALTER TABLE ");
                ltextWriter.Write(RemoveDBO(opeAlteraColuna.Table));
                ltextWriter.Write(" ALTER COLUMN ");
                ltextWriter.Write(lcmColuna.Name);
                ltextWriter.Write(" DROP DEFAULT");

                ComandoSQL(ltextWriter);
            }

            using (var ltextWriter = TextWriter())
            {
                ltextWriter.Write("ALTER TABLE ");
                ltextWriter.Write(RemoveDBO(opeAlteraColuna.Table));
                ltextWriter.Write(" ALTER COLUMN ");
                ltextWriter.Write(lcmColuna.Name);
                ltextWriter.Write(" SET DEFAULT ");
                ltextWriter.Write(
                    (lcmColuna.DefaultValue != null)
                        ? Generate((dynamic)lcmColuna.DefaultValue)
                        : lcmColuna.DefaultValueSql
                    );

                ComandoSQL(ltextWriter);
            }
        }

        protected virtual void Generate(DropTableOperation opeDropTable)
        {
            using (var ltextWriter = TextWriter())
            {
                ltextWriter.Write("DROP TABLE ");
                ltextWriter.Write(RemoveDBO(opeDropTable.Name));

                ComandoSQL(ltextWriter);
            }
        }

        protected virtual void Generate(SqlOperation opeSQL)
        {
            ComandoSQL(opeSQL.Sql, opeSQL.SuppressTransaction);
        }

         protected virtual void Generate(RenameColumnOperation opeRenomearColuna)
        {
            // Inicialmente não suportada
        }

        protected virtual void Generate(RenameTableOperation opeRenameTable)
        {
        }

        protected virtual void Generate(MoveTableOperation opeMoveTable)
        {
        }

        private void Generate(ColumnModel cmDadosColuna, IndentedTextWriter textWriter, PrimaryKeyOperation opePrimaryKey)
        {
            textWriter.Write(cmDadosColuna.Name);
            textWriter.Write(" ");
            bool lblnEhPrimaryKey = false;

            if (opePrimaryKey != null)
                lblnEhPrimaryKey = opePrimaryKey.Columns.Contains(cmDadosColuna.Name);


            if (lblnEhPrimaryKey)
            {
                if ((cmDadosColuna.Type == PrimitiveTypeKind.Int16) ||
                    (cmDadosColuna.Type == PrimitiveTypeKind.Int32))
                    textWriter.Write(" INTEGER ");
                else
                    textWriter.Write(ConstruirTipoColuna(cmDadosColuna));

                if (cmDadosColuna.IsIdentity)
                {
                    textWriter.Write(" PRIMARY KEY AUTOINCREMENT ");
                    pblnGerouPrimaryKey = true;
                }
            }
            else
            {
                textWriter.Write(ConstruirTipoColuna(cmDadosColuna));

                if ((cmDadosColuna.IsNullable != null)
                    && !cmDadosColuna.IsNullable.Value)
                {
                    textWriter.Write(" NOT NULL");
                }

                if (cmDadosColuna.DefaultValue != null)
                {
                    textWriter.Write(" DEFAULT ");
                    textWriter.Write(Generate((dynamic)cmDadosColuna.DefaultValue));
                }
                else if (!string.IsNullOrWhiteSpace(cmDadosColuna.DefaultValueSql))
                {
                    textWriter.Write(" DEFAULT ");
                    textWriter.Write(cmDadosColuna.DefaultValueSql);
                }
            }
        }

        protected virtual void Generate(HistoryOperation opeHistorico)
        {
            // Foi removido, pois atualmente não usaremos o Migration
            //using (var ltextWriter = TextWriter())
            //{
            //    if (opeHistorico is InsertHistoryOperation)
            //    {
            //        InsertHistoryOperation lhisOperacaoInsert = opeHistorico as InsertHistoryOperation;
            //        ltextWriter.Write(" INSERT INTO ");
            //        ltextWriter.Write(pstrNomeTabelaMigration);
            //        ltextWriter.Write(" ( MigrationId, Model, ProductVersion) VALUES ");
            //        ltextWriter.Write(string.Format(" ('{0}', {1}, '{2}')",
            //            lhisOperacaoInsert.MigrationId,
            //            Generate(lhisOperacaoInsert.Model), lhisOperacaoInsert.ProductVersion));
            //    }
            //    else if (opeHistorico is DeleteHistoryOperation)
            //    {
            //        DeleteHistoryOperation lhisOperacaoInsert = opeHistorico as DeleteHistoryOperation;
            //        ltextWriter.Write(" DELETE FROM ");
            //        ltextWriter.Write(pstrNomeTabelaMigration);
            //        ltextWriter.Write(string.Format(" WHERE MigrationId = '{0}'",
            //            lhisOperacaoInsert.MigrationId));
            //    }

            //    ComandoSQL(ltextWriter);
            //}
        }

        protected virtual string Generate(byte[] bytDefaultValue)
        {
            var lstrbHexString = new StringBuilder();

            foreach (var lbtByte in bytDefaultValue)
                lstrbHexString.Append(lbtByte.ToString("X2", CultureInfo.InvariantCulture));

            return "x'" + lstrbHexString + "'";
        }

        protected virtual string Generate(bool blnDefaultValue)
        {
            return blnDefaultValue ? "1" : "0";
        }

        protected virtual string Generate(DateTime dtmDefaultValue)
        {
            return "'" + dtmDefaultValue.ToString(pstrDefaultDateTime, CultureInfo.InvariantCulture) + "'";
        }

        protected virtual string Generate(DateTimeOffset dtfDefaultValue)
        {
            return "'" + dtfDefaultValue.ToString(pstrDefaultDateTime, CultureInfo.InvariantCulture) + "'";
        }

        protected virtual string Generate(Guid guidDefaultValue)
        {
            return "'" + guidDefaultValue + "'";
        }

        protected virtual string Generate(string strDefaultValue)
        {
            return "'" + strDefaultValue + "'";
        }

        protected virtual string Generate(TimeSpan tsDefaultValue)
        {
            return "'" + tsDefaultValue + "'";
        }

        protected virtual string Generate(object objDefaultValue)
        {
            return string.Format(CultureInfo.InvariantCulture, "{0}", objDefaultValue);
        }

        #endregion

        #region Métodos auxiliares

        protected virtual string ConstruirTipoColuna(ColumnModel cmModeloColuna)
        {
            return cmModeloColuna.IsTimestamp ? "rowversion" : ConstruirTipoPropriedade(cmModeloColuna);
        }

        private string ConstruirTipoPropriedade(ColumnModel propModeloPropriedade)
        {
            var lstrOriginalStoreTypeName = propModeloPropriedade.StoreType;

            if (string.IsNullOrWhiteSpace(lstrOriginalStoreTypeName))
            {
                var ltypeUsage = pprovProviderManifest.GetStoreType(propModeloPropriedade.TypeUsage).EdmType;
                lstrOriginalStoreTypeName = ltypeUsage.Name;
            }

            var lstrStoreTypeName = lstrOriginalStoreTypeName;

            const string lstrSufixoMax = "(max)";

            if (lstrStoreTypeName.EndsWith(lstrSufixoMax, StringComparison.Ordinal))
                lstrStoreTypeName = lstrStoreTypeName.Substring(0, lstrStoreTypeName.Length - lstrSufixoMax.Length) + lstrSufixoMax;

            switch (lstrOriginalStoreTypeName.ToLowerInvariant())
            {
                case "decimal":
                case "numeric":
                    lstrStoreTypeName += "(" + (propModeloPropriedade.Precision ?? pintDefaultPrecisaoNumerica)
                                     + ", " + (propModeloPropriedade.Scale ?? pintDefaultEscala) + ")";
                    break;
                case "datetime":
                case "time":
                    lstrStoreTypeName += "(" + (propModeloPropriedade.Precision ?? pbytDefaultPrecisaoTempo) + ")";
                    break;
                case "blob":
                case "varchar2":
                case "varchar":
                case "char":
                case "nvarchar":
                case "nvarchar2":
                    lstrStoreTypeName += "(" + (propModeloPropriedade.MaxLength ?? pintDefaultStringMaxLength) + ")";
                    break;
            }

            return lstrStoreTypeName;
        }

        protected void ComandoSQL(string strInstrucaoSQL, bool blnSuprimeTransacao = false)
        {
            plstComandos.Add(new MigrationStatement
            {
                Sql = strInstrucaoSQL,
                SuppressTransaction = blnSuprimeTransacao
            });
        }

        protected void ComandoSQL(IndentedTextWriter writer)
        {
            ComandoSQL(writer.InnerWriter.ToString());
        }


        protected static IndentedTextWriter TextWriter()
        {
            return new IndentedTextWriter(new StringWriter(CultureInfo.InvariantCulture));
        }

        private static string RemoveDBO(string strTexto)
        {
            return strTexto.Replace("dbo.", string.Empty);
        }

        private void GeraComandos(IEnumerable<MigrationOperation> lstOperacoesMigrations)
        {
            foreach (dynamic ldynOperacao in lstOperacoesMigrations)
                Generate(ldynOperacao);
        }


        private void InicializaServicosProvider(string strManifestoProvider)
        {
            using (var lconConexao = CreateConnection())
            {
                pprovProviderManifest = DbProviderServices
                    .GetProviderServices(lconConexao)
                    .GetProviderManifest(strManifestoProvider);
            }
        }

        protected virtual DbConnection CreateConnection()
        {
            return new SQLiteConnection();
        }

        private void GeraComandoCriacaoTabela(CreateTableOperation opeCriacaoTabela, IndentedTextWriter textWriter)
        {

            textWriter.WriteLine("CREATE TABLE " + RemoveDBO(opeCriacaoTabela.Name) + " (");
            textWriter.Indent++;

            for (int i = 0; i < opeCriacaoTabela.Columns.Count; i++)
            {
                ColumnModel lcmDadosColuna = opeCriacaoTabela.Columns.ToList()[i];
                Generate(lcmDadosColuna, textWriter, opeCriacaoTabela.PrimaryKey);

                if (i < opeCriacaoTabela.Columns.Count - 1)
                    textWriter.WriteLine(",");
            }

            if ((opeCriacaoTabela.PrimaryKey != null) && !pblnGerouPrimaryKey)
            {
                textWriter.WriteLine(",");
                textWriter.Write("CONSTRAINT ");
                textWriter.Write(RemoveDBO(opeCriacaoTabela.PrimaryKey.Name));
                textWriter.Write(" PRIMARY KEY ");
                textWriter.Write("(");

                for (int li = 0; li < opeCriacaoTabela.PrimaryKey.Columns.Count; li++)
                {
                    var lstrNomeColuna = opeCriacaoTabela.PrimaryKey.Columns[li];

                    textWriter.Write(lstrNomeColuna);

                    if (li < opeCriacaoTabela.PrimaryKey.Columns.Count - 1)
                        textWriter.WriteLine(",");
                }

                textWriter.WriteLine(")");
            }
            else
            {
                textWriter.WriteLine();
            }

            textWriter.Indent--;
            textWriter.Write(")");
        }

        #endregion

    }
}

Answer 3

对于正在寻找处理迁移的生成器的任何人，我在https://sqliteef6migrations.codeplex.com找到了一个名为“System.Data.SQLite.EF6.Migrations”的nuget包。

安装软件包后，您需要对迁移配置方法进行以下更改。

 public Configuration()
 {
    AutomaticMigrationsEnabled = false;
    SetSqlGenerator("System.Data.SQLite", new SQLiteMigrationSqlGenerator());
 }

完整的类应该看起来像这样。

namespace YourNamespace
{
    using System.Data.Entity.Migrations;
    using System.Data.SQLite.EF6.Migrations;

    internal sealed class Configuration : DbMigrationsConfiguration<YourContext>
    {
        public Configuration()
        {
            AutomaticMigrationsEnabled = false;
            SetSqlGenerator("System.Data.SQLite", new SQLiteMigrationSqlGenerator());
        }

        protected override void Seed(YourContext context)
        {
            //  This method will be called after migrating to the latest version.
        }
    }
}

Answer 4

我认为我们可以使用相同的Android概念为SQLite制作一个简单的迁移引擎。这个post显示了这个概念。当然，我们没有任何可用的MigrationSqlGenerator，但这个概念是可靠且有用的。

Answer 5

我不知道SQLite的任何内容，但是如果你试图像其他人建议的那样创建一个，你可以使用这个开源项目开始。或者您可能会发现这已经足够了吗？

http://www.codeproject.com/Articles/32977/Upgrade-framework-for-SQLite-databases

SQLite的实体框架MigrationSqlGenerator

5 个答案: