/// <summary>
/// 写入查询数据源子句。
/// </summary>
/// <param name="writer">语句写入器。</param>
/// <param name="sources">数据源集合。</param>
protected virtual void WriteFragmentForFrom(SqlWriter writer, IEnumerable <ISourceFragment> sources)
{
if (sources.Any())
{
writer.WriteLine();
writer.Write("FROM ");
sources.ForEach(() => writer.WriteLine(),
source => WriteFragmentForSource(writer, source));
}
}
/// <summary>
/// 写入过滤条件。
/// </summary>
/// <param name="writer">语句写入器。</param>
/// <param name="where">过滤条件。</param>
protected virtual void WriteFragmentForWhere(SqlWriter writer, ILogicFragment where)
{
if (where != null)
{
writer.WriteLine();
writer.Write("WHERE ");
where.WriteSql(writer);
}
}
/// <summary>
/// 写入分组语句。
/// </summary>
/// <param name="writer">语句写入器。</param>
/// <param name="groups">分组语句集合。</param>
protected virtual void WriteFragmentForGroupBy(SqlWriter writer, IEnumerable <ISqlFragment> groups)
{
if (groups.Any())
{
writer.WriteLine();
writer.Write("GROUP BY ");
groups.ForEach(() => writer.Write(", "), item => item.WriteSql(writer));
}
}
/// <summary>
/// 写入排序语句。
/// </summary>
/// <param name="writer">语句写入器。</param>
/// <param name="sorts">排序语句集合。</param>
protected virtual void WriteFragmentForOrderBy(SqlWriter writer, IEnumerable <IExpressionFragment> sorts)
{
if (sorts.Any())
{
writer.WriteLine();
writer.Write("ORDER BY ");
sorts.ForEach(() => writer.Write(", "), sort => sort.WriteSql(writer));
}
}