/// <summary>
/// Write out the TOP part of sql select statement
/// It basically writes TOP (X) [WITH TIES].
/// </summary>
/// <param name="writer"></param>
/// <param name="sqlGenerator"></param>
public void WriteSql(SqlWriter writer, SqlGenerator sqlGenerator)
{
if (SkipCount != null)
{
writer.WriteLine();
writer.Write("offset ");
writer.Write(SkipCount.GetInt(sqlGenerator) + 1);
writer.Write(" ");
}
if (TopCount != null)
{
writer.WriteLine();
writer.Write("fetch ");
if (SkipCount != null)
{
writer.Write("next ");
}
else
{
writer.Write("first ");
}
writer.Write(TopCount.GetInt(sqlGenerator));
writer.Write(" rows only ");
}
}
public void WriteSql(SqlWriter writer, SqlGenerator sqlGenerator)
{
if (IsEmpty)
{
writer.Write("*");
}
else
{
var count = Columns.Count;
var i = 0;
foreach (var column in Columns)
{
i += 1;
column.WriteSql(writer, sqlGenerator);
if (i < count)
{
writer.WriteLine(",");
}
}
}
}
/// <summary>
/// Write out a SQL select statement as a string.
/// We have to
/// <list type="number">
/// <item>Check whether the aliases extents we use in this statement have
/// to be renamed.
/// We first create a list of all the aliases used by the outer extents.
/// For each of the FromExtents( or AllJoinExtents if it is non-null),
/// rename it if it collides with the previous list.
/// </item>
/// <item>Write each of the clauses (if it exists) as a string</item>
/// </list>
/// </summary>
/// <param name="writer"></param>
/// <param name="sqlGenerator"></param>
public void WriteSql(SqlWriter writer, SqlGenerator sqlGenerator)
{
#region Check if FROM aliases need to be renamed
// Create a list of the aliases used by the outer extents
// JoinSymbols have to be treated specially.
var outerExtentAliases = GetOuterExtentAliases().ToList();
// An then rename each of the FromExtents we have
// If AllJoinExtents is non-null - it has precedence.
// The new name is derived from the old name - we append an increasing int.
var extentList = AllJoinExtents ?? FromExtents;
foreach (Symbol extent in extentList)
{
if (outerExtentAliases.Contains(extent.Name))
{
int i = sqlGenerator.AllExtentNames[extent.Name];
string newName;
do
{
++i;
newName = SqlGenerator.Format("{0}{1}", extent.Name, i);
}while (sqlGenerator.AllExtentNames.ContainsKey(newName));
sqlGenerator.AllExtentNames[extent.Name] = i;
extent.NewName = newName;
// Add extent to list of known names (although i is always incrementing, "prefix11" can
// eventually collide with "prefix1" when it is extended)
sqlGenerator.AllExtentNames[newName] = 0;
}
// Add the current alias to the list, so that the extents
// that follow do not collide with me.
outerExtentAliases.Add(extent.NewName);
}
#endregion
// Increase the indent
using (writer.Indent())
{
writer.Write("select ");
if (IsDistinct)
{
writer.Write("distinct ");
}
Select.WriteSql(writer, sqlGenerator);
writer.WriteLine();
writer.Write("from ");
From.WriteSql(writer, sqlGenerator);
if (!this.Where.IsEmpty)
{
writer.WriteLine();
writer.Write("where ");
Where.WriteSql(writer, sqlGenerator);
}
if (!this.GroupBy.IsEmpty)
{
writer.WriteLine();
writer.Write("group by ");
GroupBy.WriteSql(writer, sqlGenerator);
}
if (!this.OrderBy.IsEmpty && (IsTopMost || Top != null))
{
writer.WriteLine();
writer.Write("order by ");
OrderBy.WriteSql(writer, sqlGenerator);
}
if (!Top.IsEmpty)
{
Top.WriteSql(writer, sqlGenerator);
}
}
}
