/// <summary> /// Get an expression that represents the update operation for the specified instance. /// </summary> /// <param name="entity">The entity.</param> /// <param name="instance">The instance.</param> /// <param name="updateCheck">The update check.</param> /// <param name="selector">The selector.</param> /// <param name="indeedColumns">The indeed columns.</param> /// <param name="else">The @else.</param> /// <returns></returns> public abstract Expression GetUpdateExpression(MappingEntity entity, Expression instance, LambdaExpression updateCheck, LambdaExpression selector, ColumnIndeedExpression indeedColumns, Expression @else);
/// <summary> /// Get an expression that represents the insert operation for the specified instance. /// </summary> /// <param name="entity">The entity.</param> /// <param name="instance">The instance to insert.</param> /// <param name="selector">A lambda expression that computes a return value from the operation.</param> /// <param name="indeedColumns">指定需要插入的列.</param> /// <returns></returns> public abstract Expression GetInsertExpression(MappingEntity entity, Expression instance, LambdaExpression selector, ColumnIndeedExpression indeedColumns);
private Expression BindUpdate(IEntityTable upd, Expression instance, LambdaExpression updateCheck, LambdaExpression resultSelector, ColumnIndeedExpression columnsToBeHandled)
{
MappingEntity entity = this.mapper.Mapping.GetEntity(instance.Type, upd.TableId);
return this.Visit(this.mapper.GetUpdateExpression(entity, instance, updateCheck, resultSelector, columnsToBeHandled, null));
}
private Expression BindInsert(IEntityTable upd, Expression instance, LambdaExpression selector, ColumnIndeedExpression columnsToBeHandled)
{
MappingEntity entity = this.mapper.Mapping.GetEntity(instance.Type, upd.TableId);
return this.Visit(this.mapper.GetInsertExpression(entity, instance, selector, columnsToBeHandled));
}
public override Expression GetInsertExpression(MappingEntity entity, Expression instance, LambdaExpression selector, ColumnIndeedExpression indeedColumns)
{
var tableAlias = new TableAlias();
var table = new TableExpression(tableAlias, entity, this.mapping.GetTableName(entity));
IEnumerable<ColumnAssignment> assignments = null;
if (indeedColumns != null)
{ //TODO :2010 -7-17 更新---> 解决 过滤指定了不参与插入或者更新的列字段
assignments = this.GetColumnAssignments(table, instance, entity, (e, m) => !this.mapping.IsIdentity(e, m) && indeedColumns.FieldsToBeUpdated.ColumnsToBeHandled.Contains(m.Name) && this.mapping.IsUpdatable(e, m));
}
else //TODO :2010 -7-17 更新---> 解决 过滤指定了不参与插入或者更新的列字段
assignments = this.GetColumnAssignments(table, instance, entity, (e, m) => !this.mapping.IsIdentity(e, m) && this.mapping.IsUpdatable(e, m));
if (selector != null)
{
return new BlockCommand(
new InsertCommand(table, assignments),
this.GetInsertResult(entity, instance, selector, null)
);
}
return new InsertCommand(table, assignments);
}
/// <summary>
/// Get an expression that represents the update operation for the specified instance.
/// </summary>
/// <param name="entity">The entity.</param>
/// <param name="instance">The instance.</param>
/// <param name="updateCheck">The update check.</param>
/// <param name="selector">The selector.</param>
/// <param name="indeedColumns">The indeed columns.</param>
/// <param name="else">The @else.</param>
/// <returns></returns>
public override Expression GetUpdateExpression(MappingEntity entity, Expression instance, LambdaExpression updateCheck, LambdaExpression selector, ColumnIndeedExpression indeedColumns, Expression @else)
{
var tableAlias = new TableAlias();
var table = new TableExpression(tableAlias, entity, this.mapping.GetTableName(entity));
Expression where = null;
if (updateCheck != null)
{
Expression typeProjector = this.GetEntityExpression(table, entity);
Expression pred = DbExpressionReplacer.Replace(updateCheck.Body, updateCheck.Parameters[0], typeProjector);
where = pred;//
//TODO:解决了Update多个条件的问题2010-6-22 21:46
}
else
where = this.GetIdentityCheck(table, entity, instance);
IEnumerable<ColumnAssignment> assignments = null;// || indeedColumns.FieldsToBeUpdated.ColumnsToBeHandled.Count == 0
if (indeedColumns == null || indeedColumns.FieldsToBeUpdated == null)
{
//TODO: 2010-7-4 解决 更新自动增长列的问题
//TODO :2010 -7-17 更新---> 解决 过滤指定了不参与插入或者更新的列字段
assignments = this.GetColumnAssignments(table, instance, entity, (e, m) => !this.mapping.IsPrimaryKey(e, m) && !this.mapping.IsIdentity(e, m) && this.mapping.IsUpdatable(e, m));
}
else
{
//TODO:如果指定需要更新的字段列表有误..抛出异常
{
assignments = this.GetColumnAssignments(table, instance, entity, (e, m) => !this.mapping.IsPrimaryKey(e, m) && indeedColumns.FieldsToBeUpdated.ColumnsToBeHandled.Contains(m.Name) && !this.mapping.IsIdentity(e, m) && this.mapping.IsUpdatable(e, m));
}
}
Expression update = new UpdateCommand(table, where, assignments);
if (selector != null)
{
return new BlockCommand(
update,
new IFCommand(
this.translator.Linguist.Language.GetRowsAffectedExpression(update).GreaterThan(Expression.Constant(0)),
this.GetUpdateResult(entity, instance, selector),
@else
)
);
}
else if (@else != null)
{
return new BlockCommand(
update,
new IFCommand(
this.translator.Linguist.Language.GetRowsAffectedExpression(update).LessThanOrEqual(Expression.Constant(0)),
@else,
null
)
);
}
else
{
return update;
}
}