/// <summary>
/// 根据元数据键值获取已生成的DbContext. 使用时请模块初始化时在数据库中
/// 插入元数据地址。
/// </summary>
/// <typeparam name="T">DbContext的类型</typeparam>
/// <param name="metadatakey">
/// 元数据地址的键名。Key：Member
/// Value:metadata=res://*/Models.Member.csdl|res://*/Models.Member.ssdl|res://*/Models.Member.msl
/// </param>
/// <returns></returns>
public static T GetDbContext <T>(string metadatakey) where T : DbContext
{
T contexta = null;
var metadatainfo = DatabaseMetadataCache.Get(metadatakey);
if (metadatainfo == null)
{
var manager = new DatabaseMetadataManager();
metadatainfo = manager.GetMetadataInfo(metadatakey);
}
if (metadatainfo != null)
{
var path = string.Format("{0};{1};{2};", metadatainfo.Metadata, PROVIDER, metadatainfo.Connectionstring);
contexta = (T)Activator.CreateInstance(typeof(T), path);
}
return(contexta);
}
/// <summary>
/// Initializes a new instance of the <see cref="MySqlTableOrViewMetadata" /> class.
/// </summary>
/// <param name="metadataCache">The metadata cache.</param>
/// <param name="name">The name.</param>
/// <param name="isTable">if set to <c>true</c> is a table.</param>
/// <param name="columns">The columns.</param>
/// <param name="engine">The engine.</param>
internal MySqlTableOrViewMetadata(DatabaseMetadataCache <MySqlObjectName, MySqlDbType> metadataCache, MySqlObjectName name, bool isTable, ColumnMetadataCollection <MySqlDbType> columns, string?engine) : base(metadataCache, name, isTable, columns)
{
Engine = engine;
}
/// <summary>
/// Initializes a new instance of the <see cref="SqlServerTableOrViewMetadata{TDbType}" /> class.
/// </summary>
/// <param name="metadataCache">The metadata cache.</param>
/// <param name="name">The name.</param>
/// <param name="isTable">if set to <c>true</c> is a table.</param>
/// <param name="columns">The columns.</param>
/// <param name="hasTriggers">if set to <c>true</c> has triggers.</param>
public SqlServerTableOrViewMetadata(DatabaseMetadataCache <SqlServerObjectName, TDbType> metadataCache, SqlServerObjectName name, bool isTable, ColumnMetadataCollection <TDbType> columns, bool hasTriggers) : base(metadataCache, name, isTable, columns)
{
HasTriggers = hasTriggers;
}
/// <summary>
/// Initializes a new instance of the <see cref="TableOrViewMetadata{TObjectName, TDbType}"/> class.
/// </summary>
/// <param name="metadataCache">The metadata cache.</param>
/// <param name="name">The name.</param>
/// <param name="isTable">if set to <c>true</c> [is table].</param>
/// <param name="columns">The columns.</param>
public TableOrViewMetadata(DatabaseMetadataCache <TObjectName, TDbType> metadataCache, TObjectName name, bool isTable, ColumnMetadataCollection <TDbType> columns) : base(name.ToString() !, isTable, columns?.GenericCollection !)
