public override SqlString GetLimitString(SqlString sql, SqlString offset, SqlString limit)
{
sql = sql.Trim();
bool isForUpdate = false;
if (sql.EndsWithCaseInsensitive(" for update"))
{
sql = sql.Substring(0, sql.Length - 11);
isForUpdate = true;
}
string selectColumns = ExtractColumnOrAliasNames(sql);
var pagingSelect = new SqlStringBuilder(sql.Parts.Count + 10);
if (offset != null)
{
pagingSelect.Add("select " + selectColumns + " from ( select row_.*, rownum rownum_ from ( ");
}
else
{
pagingSelect.Add("select " + selectColumns + " from ( ");
}
pagingSelect.Add(sql);
if (offset != null && limit != null)
{
pagingSelect.Add(" ) row_ where rownum <=").Add(limit).Add(") where rownum_ >").Add(offset);
}
else if (limit != null)
{
pagingSelect.Add(" ) where rownum <=").Add(limit);
}
else
{
// offset is specified, but limit is not.
pagingSelect.Add(" ) row_ ) where rownum_ >").Add(offset);
}
if (isForUpdate)
{
pagingSelect.Add(" for update");
}
return pagingSelect.ToSqlString();
}
public override SqlString GetLimitString(SqlString sql, int offset, int limit, int? offsetParameterIndex, int? limitParameterIndex)
{
sql = sql.Trim();
bool hasOffset = offset > 0;
bool isForUpdate = false;
if (sql.EndsWithCaseInsensitive(" for update"))
{
sql = sql.Substring(0, sql.Length - 11);
isForUpdate = true;
}
var pagingSelect = new SqlStringBuilder(sql.Parts.Count + 10);
if (hasOffset)
{
pagingSelect.Add("select * from ( select row_.*, rownum rownum_ from ( ");
}
else
{
pagingSelect.Add("select * from ( ");
}
pagingSelect.Add(sql);
if (hasOffset)
{
pagingSelect.Add(" ) row_ where rownum <=").AddParameter(limitParameterIndex.Value).Add(") where rownum_ >").AddParameter(offsetParameterIndex.Value);
}
else
{
pagingSelect.Add(" ) where rownum <=").AddParameter(limitParameterIndex.Value);
}
if (isForUpdate)
{
pagingSelect.Add(" for update");
}
return pagingSelect.ToSqlString();
}