/// <summary>
/// 扩展方法: 获取Column元数据解析器
/// </summary>
/// <param name="mapperContainer">Mapper容器</param>
/// <param name="memberExpression">指定对象成员的表达式</param>
/// <returns>Column元数据解析器</returns>
public static IColumnMapper GetColumnMapper(this IMapperContainer mapperContainer, MemberExpression memberExpression)
{
//获取当前实体类型的Table元数据解析器
ITableMapper tableMapper = mapperContainer.GetTableMapper(memberExpression.Expression.Type);
//获取Column元数据解析器
return(tableMapper.GetColumnMapper(memberExpression.Member.Name));
}
/// <summary>
/// 获取基本类型的sql表达式节点
/// </summary>
/// <param name="memberExpression">成员表达式</param>
/// <returns>基本类型的sql表达式节点</returns>
protected ISqlBuilder GetColumnBuilder(MemberExpression memberExpression)
{
//若Mapper容器为空
if (_mapperContainer == null)
{
//则直接获取针对 WITH AS 临时表的sql表达式
return(new SqlBuilder("t.{0}", memberExpression.Member.Name));
}
//若不为空,则获取针对表的sql表达式
// 获取当前实体类型的Table元数据解析器
ITableMapper tableMapper = _mapperContainer.GetTableMapper(memberExpression.Expression.Type);
// 获取columnMapper
IColumnMapper columnMapper = tableMapper.GetColumnMapper(memberExpression.Member.Name);
// 获取sql列节点生成器
return(_commandTreeFactory.GetColumnBuilder(tableMapper.Header.TableAlias, columnMapper.ColumnName));
}
/// <summary>
/// 获取Where节点的子sql表达式节点
/// </summary>
/// <param name="memberExpression">成员表达式</param>
/// <param name="rightSqlExpression">右边的sql条件表达式</param>
/// <returns>Where节点的子sql表达式节点</returns>
protected INodeBuilder GetWhereChildBuilder(MemberExpression memberExpression, string rightSqlExpression)
{
//若Mapper容器为空
if (_mapperContainer == null)
{
//则直接获取针对 WITH AS 临时表的sql表达式
return(new NodeBuilder(SqlType.Where, "t.{0} {1}", memberExpression.Member.Name, rightSqlExpression));
}
//若不为空,则获取针对实体类对应的表的sql表达式
// 获取当前实体类型的Table元数据解析器
ITableMapper tableMapper = _mapperContainer.GetTableMapper(memberExpression.Expression.Type);
// 获取columnMapper
IColumnMapper columnMapper = tableMapper.GetColumnMapper(memberExpression.Member.Name);
// 获取Where节点的子sql表达式节点
return(_commandTreeFactory.GetWhereChildBuilder(tableMapper.Header.TableAlias, columnMapper.ColumnName, rightSqlExpression));
}