/// <summary>
/// 自动扫描迁移模型并添加表和列说明
/// </summary>
/// <param name="migrationBuilder">迁移构造器</param>
/// <param name="migration">迁移类实例</param>
/// <param name="entityAssembly">实体类所在程序集</param>
/// <param name="schema">架构</param>
public static void AddDatabaseDescription(this MigrationBuilder migrationBuilder, Migration migration,
Assembly entityAssembly)
{
if (entityAssembly == null)
{
throw new NullReferenceException($"{nameof(entityAssembly)} cannot be null.");
}
foreach (var entityType in migration.TargetModel.GetEntityTypes().Select(entity =>
new { EntityType = entity, ClrType = entityAssembly.GetType(entity.Name) }))
{
//添加表说明
if (entityType.ClrType?.CustomAttributes.Any(
attr => attr.AttributeType == typeof(DbDescriptionAttribute)) == true)
{
migrationBuilder.AddTableDescription(entityType.EntityType.Relational().TableName,
(entityType.ClrType.GetCustomAttribute(typeof(DbDescriptionAttribute)) as DbDescriptionAttribute
)?.Description, entityType.EntityType.Relational().Schema);
}
//添加列说明
foreach (var property in entityType.EntityType.GetProperties())
{
if (entityType.ClrType?.GetProperty(property.Name)?.CustomAttributes
.Any(attr => attr.AttributeType == typeof(DbDescriptionAttribute)) == true)
{
//如果该列的实体属性是枚举类型，把枚举的说明追加到列说明
var enumDbDescription = string.Empty;
if (entityType.ClrType?.GetProperty(property.Name)?.PropertyType.IsEnum == true ||
(entityType.ClrType?.GetProperty(property.Name)?.PropertyType
.HasImplementedRawGeneric(typeof(Nullable <>)) == true &&
entityType.ClrType?.GetProperty(property.Name)?.PropertyType.GenericTypeArguments[0]
.IsEnum == true))
{
var @enum = entityType.ClrType?.GetProperty(property.Name)?.PropertyType
.HasImplementedRawGeneric(typeof(Nullable <>)) == true
? entityType.ClrType?.GetProperty(property.Name)?.PropertyType.GenericTypeArguments[0]
: entityType.ClrType?.GetProperty(property.Name)?.PropertyType;
var descList = new List <string>();
foreach (var field in @enum?.GetFields() ?? new FieldInfo[0])
{
if (!field.IsSpecialName)
{
var desc = (field.GetCustomAttributes(typeof(DbDescriptionAttribute), false)
.FirstOrDefault() as DbDescriptionAttribute)?.Description;
descList.Add(
$@"{field.GetRawConstantValue()} : {(desc.IsNullOrWhiteSpace() ? field.Name : desc)}");
}
}
var enumTypeDbDescription =
(@enum?.GetCustomAttributes(typeof(DbDescriptionAttribute), false).FirstOrDefault() as
DbDescriptionAttribute)?.Description;
enumDbDescription =
$@"( {(enumTypeDbDescription.IsNullOrWhiteSpace() ? "" : $@"{enumTypeDbDescription}; ")}{string.Join("; ", descList)} )";
}
migrationBuilder.AddColumnDescription(entityType.EntityType.Relational().TableName,
property.Relational().ColumnName,
$@"{(entityType.ClrType?.GetProperty(property.Name)
?.GetCustomAttribute(typeof(DbDescriptionAttribute)) as DbDescriptionAttribute)
?.Description}{(enumDbDescription.IsNullOrWhiteSpace() ? "" : $@" {enumDbDescription}")}"