public override SqlString GetLimitString(SqlString querySqlString, SqlString offset, SqlString limit)
{
var tokenEnum = new SqlTokenizer(querySqlString).GetEnumerator();
if (!tokenEnum.TryParseUntilFirstMsSqlSelectColumn()) return null;
var result = new SqlStringBuilder(querySqlString);
if (!tokenEnum.TryParseUntil("order"))
{
result.Add(" ORDER BY CURRENT_TIMESTAMP");
}
result.Add(" OFFSET ");
if (offset != null)
{
result.Add(offset).Add(" ROWS");
}
else
{
result.Add("0 ROWS");
}
if (limit != null)
{
result.Add(" FETCH FIRST ").Add(limit).Add(" ROWS ONLY");
}
return result.ToSqlString();
}
public override SqlString GetLimitString(SqlString querySqlString, SqlString offset, SqlString limit)
{
using (var tokenEnum = new SqlTokenizer(querySqlString).GetEnumerator())
{
if (!tokenEnum.TryParseUntilFirstMsSqlSelectColumn())
{
return(null);
}
var result = new SqlStringBuilder(querySqlString);
if (!tokenEnum.TryParseUntil("order"))
{
result.Add(" ORDER BY CURRENT_TIMESTAMP");
}
result.Add(" OFFSET ");
if (offset != null)
{
result.Add(offset).Add(" ROWS");
}
else
{
result.Add("0 ROWS");
}
if (limit != null)
{
result.Add(" FETCH FIRST ").Add(limit).Add(" ROWS ONLY");
}
return(result.ToSqlString());
}
}
public MsSqlSelectParser(SqlString sql)
{
if (sql == null) throw new ArgumentNullException("sql");
this.Sql = sql;
this.SelectIndex = this.FromIndex = this.OrderByIndex = -1;
var tokenEnum = new SqlTokenizer(sql).GetEnumerator();
tokenEnum.MoveNext();
// Custom SQL may contain multiple SELECT statements, for example to assign parameters.
// Therefore we loop over SELECT statements until a SELECT is found that returns data.
SqlToken selectToken;
bool isDistinct;
if (tokenEnum.TryParseUntilFirstMsSqlSelectColumn(out selectToken, out isDistinct))
{
this.SelectIndex = selectToken.SqlIndex;
this.IsDistinct = isDistinct;
_columns.AddRange(ParseColumnDefinitions(tokenEnum));
if (tokenEnum.TryParseUntil("from"))
{
this.FromIndex = tokenEnum.Current.SqlIndex;
SqlToken orderToken;
if (tokenEnum.TryParseUntilFirstOrderColumn(out orderToken))
{
this.OrderByIndex = orderToken.SqlIndex;
foreach (var order in ParseOrderDefinitions(tokenEnum))
{
_orders.Add(order);
if (!order.Column.InSelectClause)
{
_columns.Add(order.Column);
}
}
}
}
return;
}
}
