/// <summary>
/// 将一个 <see cref="DataRow"/> 转换为一个 <typeparamref name="T"/> 的对象。
/// </summary>
/// <param name="row">一个 <see cref="DataRow"/> 对象。</param>
/// <returns>由 <see cref="DataRow"/> 中数据转换成的 <typeparamref name="T"/> 对象实例。</returns>
public virtual T Map(DataRow row)
{
var converter = ConvertManager.GetConverter(typeof(T));
if (converter != null)
{
return((T)converter.ConvertFrom(row[0], row.Table.Columns[0].DataType.GetDbType()));
}
return(row[0].To <object, T>());
}
internal static TC ToTypeEx <TS, TC>(this TS value)
{
var converter = ConvertManager.GetConverter(typeof(TC));
if (converter != null)
{
return((TC)converter.ConvertFrom(value, typeof(TC).GetDbType()));
}
return(value.To <TS, TC>());
}
protected override Expression VisitColumn(ColumnExpression column)
{
ParameterExpression recordWrapper;
ParameterExpression dataReader;
int ordinal;
if (scope != null && scope.TryGetValue(column, out recordWrapper, out dataReader, out ordinal))
{
if (!column.Type.IsDbTypeSupported())
{
throw new InvalidCastException(SR.GetString(SRKind.InvalidCastPropertyValue, column.Type.FullName));
}
//把 ColumnExpression 换成 RecordWrapper.GetInt32(IDataReader, int) 这样的表达式
var dbType = column.MapInfo != null && column.MapInfo.DataType != null ?
(DbType)column.MapInfo.DataType : column.Type.GetDbType();
var method = RecordWrapHelper.GetMethodByOrdinal(dbType);
Expression expression = Expression.Call(recordWrapper, method, dataReader, Expression.Constant(ordinal));
//先找转换器
var converter = ConvertManager.GetConverter(column.Type);
if (converter != null)
{
//调用ConvertManager.GetConverter
var mconverter = Expression.Call(null, MthGetConverter, Expression.Constant(column.Type));
//调用 IValueConverter.ConvertFrom
expression = (Expression)Expression.Convert(
Expression.Call(mconverter, MthConvert, expression, Expression.Constant(dbType)),
column.Type);
}
else
{
if (column.Type.IsNullableType())
{
//调用 RecordWrapper.IsDbNull 判断值是否为空
expression = (Expression)Expression.Condition(
Expression.Call(recordWrapper, MthIsDbNull, dataReader, Expression.Constant(ordinal)),
Expression.Convert(Expression.Constant(null), column.Type),
Expression.Convert(expression, column.Type));
}
else if (column.Type != method.ReturnType)
{
expression = (Expression)Expression.Convert(expression, column.Type);
}
}
return(expression);
}
return(column);
}
/// <summary>
/// 将一个 <see cref="IDataReader"/> 转换为一个 <typeparamref name="T"/> 的对象。
/// </summary>
/// <param name="database">当前的 <see cref="IDatabase"/> 对象。</param>
/// <param name="reader">一个 <see cref="IDataReader"/> 对象。</param>
/// <returns>由当前 <see cref="IDataReader"/> 对象中的数据转换成的 <typeparamref name="T"/> 对象实例。</returns>
public virtual T Map(IDatabase database, IDataReader reader)
{
var value = RecordWrapper == null ? reader[0] :
RecordWrapper.GetValue(reader, 0);
var converter = ConvertManager.GetConverter(typeof(T));
if (converter != null)
{
return((T)converter.ConvertFrom(value, reader.GetFieldType(0).GetDbType()));
}
return(value.To <object, T>());
}
/// <summary>
/// 将一个 <see cref="IDataReader"/> 转换为一个 <typeparamref name="T"/> 的对象。
/// </summary>
/// <param name="reader">一个 <see cref="IDataReader"/> 对象。</param>
/// <returns>由当前 <see cref="IDataReader"/> 对象中的数据转换成的 <typeparamref name="T"/> 对象实例。</returns>
public virtual T Map(IDataReader reader)
{
var index = reader.FieldCount != 1 ? 1 : 0;
var value = RecordWrapper == null ? reader[index] :
RecordWrapper.GetValue(reader, index);
var converter = ConvertManager.GetConverter(typeof(T));
if (converter != null)
{
return((T)converter.ConvertFrom(value, reader.GetFieldType(index).GetDbType()));
}
return(value.To <object, T>());
}
/// <summary>
/// 使用当前的记录填充数组。
/// </summary>
/// <param name="mappings">名称和类型的映射字典。</param>
/// <param name="item">当前的数据项。</param>
/// <param name="data">数组的数组。</param>
/// <param name="batch">当前批次中的索引。</param>
private void FillArrayData(IEnumerable <PropertyFieldMapping> mappings, object item, object[][] data, int batch)
{
mappings.ForEach((m, i) =>
{
var value = m.ValueFunc(item);
if (value != null)
{
var converter = ConvertManager.GetConverter(m.PropertyType);
if (converter != null)
{
value = converter.ConvertTo(value, m.FieldType);
}
}
data[i][batch] = value;
});
}
private PropertyValue GetConvertedValue(PropertyMapping mapper, bool isNull, Func <int, object> funcGetValue)
{
var converter = ConvertManager.GetConverter(mapper.Property.Type);
if (converter == null)
{
throw new NotSupportedException(SR.GetString(SRKind.UnableConvertComplexType, mapper.Property.Type));
}
if (isNull)
{
return(PropertyValue.Empty);
}
var dbType = mapper.Property.Info.DataType ?? DbType.String;
return(PropertyValue.NewValue(converter.ConvertFrom(funcGetValue(mapper.Index), dbType)));
}
/// <summary>
/// 获取受 <see cref="IValueConverter"/> 支持的数据转换值。
/// </summary>
/// <param name="entity"></param>
/// <param name="property"></param>
/// <returns></returns>
private static object GetConvertableValue(IEntity entity, IProperty property)
{
var value = entity.GetValue(property);
if (!PropertyValue.IsEmpty(value))
{
//查找属性类型对应的转换器
var converter = ConvertManager.GetConverter(property.Type);
if (converter != null && property.Info.DataType != null)
{
var pvValue = value.GetValue();
return(converter.ConvertTo(pvValue, (DbType)property.Info.DataType));
}
return(value.GetValue());
}
return(property.Type.GetDefaultValue());
}
/// <summary>
/// 使用当前的记录填充数组。
/// </summary>
/// <param name="mappings">名称和类型的映射字典。</param>
/// <param name="item">当前的数据项。</param>
/// <param name="data">数组的数组。</param>
/// <param name="batch">当前批次中的索引。</param>
private void FillArrayData(IEnumerable <PropertyFieldMapping> mappings, object item, object[][] data, int batch)
{
var i = 0;
foreach (var map in mappings)
{
var value = map.ValueFunc(item);
if (value != null)
{
var converter = ConvertManager.GetConverter(map.PropertyType);
if (converter != null)
{
value = converter.ConvertTo(value, map.FieldType);
}
}
data[i++][batch] = value;
}
}
/// <summary>
/// 获取受 <see cref="IValueConverter"/> 支持的数据转换值。
/// </summary>
/// <param name="entity"></param>
/// <param name="property"></param>
/// <returns></returns>
private static object GetConvertableValue(IEntity entity, IProperty property)
{
var value = entity.InternalGetValue(property);
if (!value.IsNullOrEmpty())
{
var converter = ConvertManager.GetConverter(property.Type);
if (converter != null)
{
var storageValue = value.GetStorageValue();
var convertValue = converter.ConvertTo(storageValue, (DbType)property.Info.DataType);
return(convertValue);
}
return(value.GetStorageValue());
}
return(property.Type.GetDefaultValue());
}
internal static NamedValueExpression GetNamedValueExpression(string name, Expression value, DbType dbType)
{
var exp = value;
if (exp.NodeType == ExpressionType.Convert)
{
exp = ((UnaryExpression)value).Operand;
}
if (exp.NodeType != ExpressionType.Constant)
{
return(new NamedValueExpression(name, exp));
}
IValueConverter converter;
if ((converter = ConvertManager.GetConverter(exp.Type)) != null)
{
exp = Expression.Constant(converter.ConvertTo(((ConstantExpression)exp).Value, dbType));
exp = Expression.Convert(exp, typeof(object));
}
return(new NamedValueExpression(name, exp, dbType));
}
/// <summary>
/// 根据指定的<see cref="PropertyValue"/> 来设置 <see cref="Parameter"/> 的值。
/// </summary>
/// <param name="value"></param>
/// <param name="parameter"></param>
/// <returns></returns>
public static Parameter Parametrization(PropertyValue value, Parameter parameter)
{
switch (value.StorageType)
{
case StorageType.Boolean:
parameter.Value = value.Boolean;
parameter.DbType = DbType.Boolean;
break;
case StorageType.Byte:
parameter.Value = value.Byte;
parameter.DbType = DbType.Byte;
break;
case StorageType.ByteArray:
parameter.Value = value.ByteArray;
parameter.DbType = DbType.Binary;
break;
case StorageType.Char:
parameter.Value = value.Char;
parameter.DbType = DbType.AnsiString;
break;
case StorageType.DateTime:
parameter.Value = value.DateTime;
parameter.DbType = DbType.DateTime;
break;
case StorageType.Decimal:
parameter.Value = value.Decimal;
parameter.DbType = DbType.Decimal;
break;
case StorageType.Double:
parameter.Value = value.Double;
parameter.DbType = DbType.Double;
break;
case StorageType.Enum:
parameter.Value = value.Enum.To <int>();
parameter.DbType = DbType.Int32;
break;
case StorageType.Guid:
parameter.Value = value.Guid;
parameter.DbType = DbType.Guid;
break;
case StorageType.Int16:
parameter.Value = value.Int16;
parameter.DbType = DbType.Int16;
break;
case StorageType.Int32:
parameter.Value = value.Int32;
parameter.DbType = DbType.Int32;
break;
case StorageType.Int64:
parameter.Value = value.Int64;
parameter.DbType = DbType.Int64;
break;
case StorageType.Single:
parameter.Value = value.Single;
parameter.DbType = DbType.Single;
break;
case StorageType.String:
parameter.Value = value.String;
parameter.DbType = DbType.AnsiString;
break;
case StorageType.TimeSpan:
parameter.Value = value.TimeSpan;
parameter.DbType = DbType.Time;
break;
case StorageType.Object:
var converter = ConvertManager.GetConverter(value.Object.GetType());
if (converter != null)
{
var dbType = value.DataType ?? DbType.String;
parameter.Value = converter.ConvertTo(value.Object, dbType);
parameter.DbType = dbType;
}
break;
}
return(parameter);
}
private Expression BuildExecuteBatch(BatchCommandExpression batch)
{
var operation = Parameterize(batch.Operation.Body);
var result = _translator.Translate(operation);
var namedValues = NamedValueGatherer.Gather(operation);
var table = new DataTable();
foreach (var nv in namedValues)
{
var info = GetPropertyInfoFromExpression(nv.Value);
if (info != null)
{
table.Columns.Add(nv.Name, info.DataType.Value.FromDbType());
}
else
{
table.Columns.Add(nv.Name, DataExpressionRow.CreateType(nv.Value.Type));
}
}
var parameters = namedValues.ToDictionary(s => s.Name, s =>
{
var expression = s.Value;
var info = GetPropertyInfoFromExpression(expression);
if (info == null)
{
return(expression);
}
if (ConvertManager.GetConverter(expression.Type) != null)
{
var convExp = Expression.Call(null, MethodCache.GetConverter, Expression.Constant(expression.Type));
expression = Expression.Call(convExp, MethodCache.ConvertTo, expression, Expression.Constant((DbType)info.DataType));
}
return((object)Expression.Lambda(expression, batch.Operation.Parameters[1]).Compile());
});
var entities = (IEnumerable)batch.Input.Value;
foreach (IEntity entity in entities)
{
var row = table.NewRow();
foreach (var nv in parameters)
{
if (nv.Value is Delegate del)
{
row[nv.Key] = del.DynamicInvoke(entity) ?? DBNull.Value;
}
else if (nv.Value is Expression exp)
{
exp = ParameterRewriter.Rewrite(exp, batch.Operation.Parameters[1], entity);
var setter = Expression.Lambda(exp, _executor).Compile();
row[nv.Key] = DataExpressionRow.Create(exp.Type, setter);
}
}
table.Rows.Add(row);
}
Expression plan;
if (_isAsync)
{
_cancelToken = Expression.Parameter(typeof(CancellationToken), "token");
plan = Expression.Call(_executor, MethodCache.DbUpdateAsync,
Expression.Constant(table),
Expression.Constant((SqlCommand)result.QueryText),
Expression.Constant(null, typeof(SqlCommand)),
Expression.Constant(null, typeof(SqlCommand)),
_cancelToken
);
}
else
{
plan = Expression.Call(_executor, MethodCache.DbUpdate,
Expression.Constant(table),
Expression.Constant((SqlCommand)result.QueryText),
Expression.Constant(null, typeof(SqlCommand)),
Expression.Constant(null, typeof(SqlCommand))
);
}
if (operation.NodeType != (ExpressionType)DbExpressionType.Insert)
{
return(plan);
}
return(Expression.Call(typeof(ExecutionBuilder),
_isAsync ? nameof(ExecutionBuilder.UpdateEntitiesAsync) : nameof(ExecutionBuilder.UpdateEntities), null,
plan,
Expression.Constant(table, typeof(DataTable)),
Expression.Constant(entities, typeof(IEnumerable))));
}