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Question

我正在尝试创建一个简单的表，其中主键是自动插入整数。 因此，我做的是创建.NET类并试图创建迁移。

这是班级的：

public class PasswordEntry : IEntity<int>
{
    [Key]
    [Column("Id", Order = 0, TypeName = DatabaseType.INT)]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int Id { get; set; }

    [Column("Title", Order = 1, TypeName = "nvarchar2(300)")]
    [Required(AllowEmptyStrings = false), MaxLength(300)]
    public string Title { get; set; } = default!;

    [Column("UserName", Order = 2, TypeName = "nvarchar2(2000)")]
    [MaxLength(2000)]
    public string? UserName { get; set; }

    [Column("Password", Order = 3, TypeName = "nvarchar2(4000)")]
    [MaxLength(4000)]
    public string? PasswordHash { get; set; }

    [Column("Url", Order = 4, TypeName = "nvarchar2(5000)")]
    [MaxLength(5000)]
    public string? Url { get; set; }
}

这就是上下文：

internal sealed class DatabaseContext : DbContext
{
    public DatabaseContext(string databasePath)
    {
        _dbPath = databasePath;
    }
    
    private readonly string _dbPath;

    protected override void OnConfiguring(DbContextOptionsBuilder options)
        => options.UseSqlite($"Data Source={_dbPath}");

    
    public DbSet<PasswordEntry> PasswordEntries { get; set; } = default!;
}

生成的迁移up -Method是：

protected override void Up(MigrationBuilder migrationBuilder)
{
    migrationBuilder.CreateTable(
        name: "PasswordEntries",
        columns: table => new
        {
            Id = table.Column<int>(type: "int", nullable: false)
                .Annotation("Sqlite:Autoincrement", true),
            Title = table.Column<string>(type: "nvarchar2(300)", maxLength: 300, nullable: false),
            UserName = table.Column<string>(type: "nvarchar2(2000)", maxLength: 2000, nullable: true),
            Password = table.Column<string>(type: "nvarchar2(4000)", maxLength: 4000, nullable: true),
            Url = table.Column<string>(type: "nvarchar2(5000)", maxLength: 5000, nullable: true)
        },
        constraints: table =>
        {
            table.PrimaryKey("PK_PasswordEntries", x => x.Id);
        });
}

并且当我尝试更新数据库时，我会得到错误消息：

Applying migration '20220407093200_AddedPasswordEntryTable'.
Failed executing DbCommand (2ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
CREATE TABLE "PasswordEntries" (
    "Id" int NOT NULL CONSTRAINT "PK_PasswordEntries" PRIMARY KEY AUTOINCREMENT,
    "Title" nvarchar2(300) NOT NULL,
    "UserName" nvarchar2(2000) NULL,
    "Password" nvarchar2(4000) NULL,
    "Url" nvarchar2(5000) NULL
);
Microsoft.Data.Sqlite.SqliteException (0x80004005): SQLite Error 1: 'AUTOINCREMENT is only allowed on an INTEGER PRIMARY KEY'.
   at Microsoft.Data.Sqlite.SqliteException.ThrowExceptionForRC(Int32 rc, sqlite3 db)
   at Microsoft.Data.Sqlite.SqliteCommand.PrepareAndEnumerateStatements(Stopwatch timer)+MoveNext()
   at Microsoft.Data.Sqlite.SqliteCommand.GetStatements(Stopwatch timer)+MoveNext()
   at Microsoft.Data.Sqlite.SqliteDataReader.NextResult()
   at Microsoft.Data.Sqlite.SqliteCommand.ExecuteReader(CommandBehavior behavior)
   at Microsoft.Data.Sqlite.SqliteCommand.ExecuteReader()
   at Microsoft.Data.Sqlite.SqliteCommand.ExecuteNonQuery()
   at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteNonQuery(RelationalCommandParameterObject parameterObject)
   at Microsoft.EntityFrameworkCore.Migrations.MigrationCommand.ExecuteNonQuery(IRelationalConnection connection, IReadOnlyDictionary`2 parameterValues)
   at Microsoft.EntityFrameworkCore.Migrations.Internal.MigrationCommandExecutor.ExecuteNonQuery(IEnumerable`1 migrationCommands, IRelationalConnection connection)
   at Microsoft.EntityFrameworkCore.Migrations.Internal.Migrator.Migrate(String targetMigration)
   at Microsoft.EntityFrameworkCore.Design.Internal.MigrationsOperations.UpdateDatabase(String targetMigration, String connectionString, String contextType)
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.UpdateDatabaseImpl(String targetMigration, String connectionString, String contextType)
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.UpdateDatabase.<>c__DisplayClass0_0.<.ctor>b__0()
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute(Action action)
SQLite Error 1: 'AUTOINCREMENT is only allowed on an INTEGER PRIMARY KEY'.

但是迁移和更新都证明id -column是一个整数...任何想法在这里有什么问题？

Answer 1

错误信息：

“仅在整数主键上允许自动增量”
但你的类型是“int”

正确的sql应该是这样的，（不是int）

Id = table.Column<integer>(type: "int", nullable: false)
                .Annotation("Sqlite:Autoincrement", true),AUTOINCREMENT,

你不需要在Entity Id中进行类型定义。 ef core会自动识别出它是key，“Integer”并且是Required。

public int Id { get; set; }

Answer 2

我认为问题是您拥有的 [DatabaseGenerate(DatabaseGenerateOption.Identity)] 属性。删除它或执行以下操作：

[Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]