C# 带有时态表的实体框架核心3.1-访问SysStartTime和SysEndTime_C#_.net_.net Core_Entity Framework Core_Temporal Tables

C# 带有时态表的实体框架核心3.1-访问SysStartTime和SysEndTime

c# .net .net-core entity-framework-core

C# 带有时态表的实体框架核心3.1-访问SysStartTime和SysEndTime,c#,.net,.net-core,entity-framework-core,temporal-tables,C#,.net,.net Core,Entity Framework Core,Temporal Tables,我已经基于Microsoft SQL文档创建了时态表，创建了一个带有默认历史记录表的时态表迁移： public partial class Temporaltables : Migration { List<string> tablesToUpdate = new List<string> { "Images", "Languages",

我已经基于Microsoft SQL文档创建了时态表，创建了一个带有默认历史记录表的时态表

迁移：

public partial class Temporaltables : Migration
{
    List<string> tablesToUpdate = new List<string>
        {
           "Images",
           "Languages",
           "Questions",
           "Texts",
           "Medias",
        };

    protected override void Up(MigrationBuilder migrationBuilder)
    {
        migrationBuilder.Sql($"CREATE SCHEMA History");
        foreach (var table in tablesToUpdate)
        {
            string alterStatement = $@"ALTER TABLE [{table}] ADD SysStartTime datetime2(0) GENERATED ALWAYS AS ROW START HIDDEN
     CONSTRAINT DF_{table}_SysStart DEFAULT GETDATE(), SysEndTime datetime2(0) GENERATED ALWAYS AS ROW END HIDDEN
     CONSTRAINT DF_{table}_SysEnd DEFAULT CONVERT(datetime2 (0), '9999-12-31 23:59:59'),
     PERIOD FOR SYSTEM_TIME (SysStartTime, SysEndTime)";
            migrationBuilder.Sql(alterStatement);
            alterStatement = $@"ALTER TABLE [{table}] SET (SYSTEM_VERSIONING = ON (HISTORY_TABLE = History.[{table}]));";
            migrationBuilder.Sql(alterStatement);
        }
    }

    protected override void Down(MigrationBuilder migrationBuilder)
    {
        foreach (var table in tablesToUpdate)
        {
            string alterStatement = $@"ALTER TABLE [{table}] SET (SYSTEM_VERSIONING = OFF);";
            migrationBuilder.Sql(alterStatement);
            alterStatement = $@"ALTER TABLE [{table}] DROP PERIOD FOR SYSTEM_TIME";
            migrationBuilder.Sql(alterStatement);
            alterStatement = $@"ALTER TABLE [{table}] DROP DF_{table}_SysStart, DF_{table}_SysEnd";
            migrationBuilder.Sql(alterStatement);
            alterStatement = $@"ALTER TABLE [{table}] DROP COLUMN SysStartTime, COLUMN SysEndTime";
            migrationBuilder.Sql(alterStatement);
            alterStatement = $@"DROP TABLE History.[{table}]";
            migrationBuilder.Sql(alterStatement);
        }
        migrationBuilder.Sql($"DROP SCHEMA History");
    }
}

ApplicationDbContext.cs：

protected override void OnModelCreating(ModelBuilder modelBuilder)
{...

    foreach (var et in modelBuilder.Model.GetEntityTypes())
    {
        foreach (var prop in et.GetProperties())
        {
            if (prop.Name == "SysStartTime" || prop.Name == "SysEndTime")
            {
                prop.ValueGenerated = Microsoft.EntityFrameworkCore.Metadata.ValueGenerated.OnAddOrUpdate;
            }
        }
    }

protected override void OnModelCreating(ModelBuilder modelBuilder)
{...

    foreach (var et in modelBuilder.Model.GetEntityTypes())
    {
        foreach (var prop in et.GetProperties())
        {
            if (prop.Name == "SysStartTime" || prop.Name == "SysEndTime")
            {
                prop.ValueGenerated = Microsoft.EntityFrameworkCore.Metadata.ValueGenerated.OnAddOrUpdate;
            }
        }
    }

及

对于已经有列的表，我只是删除了迁移的

Up

和

Down

值，然后它就工作了：

migrationBuilder.AddColumn<DateTime>(
    name: "SysStartTime",
    table: "Questions",
    type: "datetime2(0)",
    nullable: false,
    defaultValue: new DateTime(1, 1, 1, 0, 0, 0, 0, DateTimeKind.Unspecified));

ApplicationDbContext.cs：

protected override void OnModelCreating(ModelBuilder modelBuilder)
{...

    foreach (var et in modelBuilder.Model.GetEntityTypes())
    {
        foreach (var prop in et.GetProperties())
        {
            if (prop.Name == "SysStartTime" || prop.Name == "SysEndTime")
            {
                prop.ValueGenerated = Microsoft.EntityFrameworkCore.Metadata.ValueGenerated.OnAddOrUpdate;
            }
        }
    }

protected override void OnModelCreating(ModelBuilder modelBuilder)
{...

    foreach (var et in modelBuilder.Model.GetEntityTypes())
    {
        foreach (var prop in et.GetProperties())
        {
            if (prop.Name == "SysStartTime" || prop.Name == "SysEndTime")
            {
                prop.ValueGenerated = Microsoft.EntityFrameworkCore.Metadata.ValueGenerated.OnAddOrUpdate;
            }
        }
    }

迁移，如果您已经有

架构历史记录

，则删除这些行：

public partial class Temporaltables : Migration
{
    List<string> tablesToUpdate = new List<string>
        {
           "NewTable1",
           "NewTable2",
        };

    protected override void Up(MigrationBuilder migrationBuilder)
    {
        migrationBuilder.Sql($"CREATE SCHEMA History");
        foreach (var table in tablesToUpdate)
        {
            string alterStatement = $@"ALTER TABLE [{table}] 
                ADD PERIOD FOR SYSTEM_TIME ([SysStartTime], [SysEndTime])";
            migrationBuilder.Sql(alterStatement);
            alterStatement = $@"ALTER TABLE [{table}] 
                SET (SYSTEM_VERSIONING = ON (HISTORY_TABLE = History.[{table}], DATA_CONSISTENCY_CHECK = ON));";
            migrationBuilder.Sql(alterStatement);
        }
    }

    protected override void Down(MigrationBuilder migrationBuilder)
    {
        foreach (var table in tablesToUpdate)
        {
            string alterStatement = $@"ALTER TABLE [{table}] SET (SYSTEM_VERSIONING = OFF);";
            migrationBuilder.Sql(alterStatement);
            alterStatement = $@"ALTER TABLE [{table}] DROP PERIOD FOR SYSTEM_TIME";
            migrationBuilder.Sql(alterStatement);
            alterStatement = $@"DROP TABLE History.[{table}]";
            migrationBuilder.Sql(alterStatement);
        }
        migrationBuilder.Sql($"DROP SCHEMA History");
    }
}

公共部分类临时表：迁移
{
列表表更新=新列表
{
“新表格1”，
“新表格2”，
};
受保护的覆盖作废（MigrationBuilder MigrationBuilder）
{
Sql（$“创建架构历史”）；
foreach（表更新中的var表）
{
字符串alterStatement=$@“ALTER TABLE[{TABLE}]
为系统时间（[SysStartTime]、[SysEndTime]）添加时段；
Sql（alterStatement）；
alterStatement=$@“ALTER TABLE[{TABLE}]
设置（SYSTEM_VERSIONING=ON（HISTORY_TABLE=HISTORY。[{TABLE}]，DATA_CONSISTENCY_CHECK=ON））；“；
Sql（alterStatement）；
}
}
受保护的覆盖无效关闭（MigrationBuilder MigrationBuilder）
{
foreach（表更新中的var表）
{
字符串alterStatement=$@“ALTERTABLE[{TABLE}]集合（SYSTEM_VERSIONING=OFF）；”；
Sql（alterStatement）；
alterStatement=$@“ALTER TABLE[{TABLE}]系统时间的删除周期”；
Sql（alterStatement）；
alterStatement=$@“删除表历史记录。[{TABLE}]”；
Sql（alterStatement）；
}
Sql（$“删除模式历史”）；
}
}

关于GitHub的讨论：

对于已经有列的表，我只是简单地删除了迁移的

Up

和

Down

值，然后它就工作了：

migrationBuilder.AddColumn<DateTime>(
    name: "SysStartTime",
    table: "Questions",
    type: "datetime2(0)",
    nullable: false,
    defaultValue: new DateTime(1, 1, 1, 0, 0, 0, 0, DateTimeKind.Unspecified));

ApplicationDbContext.cs：

protected override void OnModelCreating(ModelBuilder modelBuilder)
{...

    foreach (var et in modelBuilder.Model.GetEntityTypes())
    {
        foreach (var prop in et.GetProperties())
        {
            if (prop.Name == "SysStartTime" || prop.Name == "SysEndTime")
            {
                prop.ValueGenerated = Microsoft.EntityFrameworkCore.Metadata.ValueGenerated.OnAddOrUpdate;
            }
        }
    }

protected override void OnModelCreating(ModelBuilder modelBuilder)
{...

    foreach (var et in modelBuilder.Model.GetEntityTypes())
    {
        foreach (var prop in et.GetProperties())
        {
            if (prop.Name == "SysStartTime" || prop.Name == "SysEndTime")
            {
                prop.ValueGenerated = Microsoft.EntityFrameworkCore.Metadata.ValueGenerated.OnAddOrUpdate;
            }
        }
    }

迁移，如果您已经有

架构历史记录

，则删除这些行：

public partial class Temporaltables : Migration
{
    List<string> tablesToUpdate = new List<string>
        {
           "NewTable1",
           "NewTable2",
        };

    protected override void Up(MigrationBuilder migrationBuilder)
    {
        migrationBuilder.Sql($"CREATE SCHEMA History");
        foreach (var table in tablesToUpdate)
        {
            string alterStatement = $@"ALTER TABLE [{table}] 
                ADD PERIOD FOR SYSTEM_TIME ([SysStartTime], [SysEndTime])";
            migrationBuilder.Sql(alterStatement);
            alterStatement = $@"ALTER TABLE [{table}] 
                SET (SYSTEM_VERSIONING = ON (HISTORY_TABLE = History.[{table}], DATA_CONSISTENCY_CHECK = ON));";
            migrationBuilder.Sql(alterStatement);
        }
    }

    protected override void Down(MigrationBuilder migrationBuilder)
    {
        foreach (var table in tablesToUpdate)
        {
            string alterStatement = $@"ALTER TABLE [{table}] SET (SYSTEM_VERSIONING = OFF);";
            migrationBuilder.Sql(alterStatement);
            alterStatement = $@"ALTER TABLE [{table}] DROP PERIOD FOR SYSTEM_TIME";
            migrationBuilder.Sql(alterStatement);
            alterStatement = $@"DROP TABLE History.[{table}]";
            migrationBuilder.Sql(alterStatement);
        }
        migrationBuilder.Sql($"DROP SCHEMA History");
    }
}

公共部分类临时表：迁移
{
列表表更新=新列表
{
“新表格1”，
“新表格2”，
};
受保护的覆盖作废（MigrationBuilder MigrationBuilder）
{
Sql（$“创建架构历史”）；
foreach（表更新中的var表）
{
字符串alterStatement=$@“ALTER TABLE[{TABLE}]
为系统时间（[SysStartTime]、[SysEndTime]）添加时段；
Sql（alterStatement）；
alterStatement=$@“ALTER TABLE[{TABLE}]
设置（SYSTEM_VERSIONING=ON（HISTORY_TABLE=HISTORY。[{TABLE}]，DATA_CONSISTENCY_CHECK=ON））；“；
Sql（alterStatement）；
}
}
受保护的覆盖无效关闭（MigrationBuilder MigrationBuilder）
{
foreach（表更新中的var表）
{
字符串alterStatement=$@“ALTERTABLE[{TABLE}]集合（SYSTEM_VERSIONING=OFF）；”；
Sql（alterStatement）；
alterStatement=$@“ALTER TABLE[{TABLE}]系统时间的删除周期”；
Sql（alterStatement）；
alterStatement=$@“删除表历史记录。[{TABLE}]”；
Sql（alterStatement）；
}
Sql（$“删除模式历史”）；
}
}

关于GitHub的讨论：