/// <summary>
/// Convert Outer Join.
/// Converting joins can ve very complex when multiple tables/keys are involved.
/// The main scenarios supported are two tables with multiple key columns
/// and multiple tables with single key columns.
/// <pre>
/// SELECT a.Col1, b.Col2 FROM tableA a, tableB b WHERE a.ID=b.ID(+)
/// => SELECT a.Col1, b.Col2 FROM tableA a LEFT OUTER JOIN tableB b ON (a.ID=b.ID)
/// SELECT a.Col1, b.Col2 FROM tableA a, tableB b WHERE a.ID(+)=b.ID
/// => SELECT a.Col1, b.Col2 FROM tableA a RIGHT OUTER JOIN tableB b ON (a.ID=b.ID)
/// Assumptions:
/// - No outer joins in sub queries (ignores sub-queries)
/// - OR condition ignored (not sure what to do, should not happen)
/// Limitations:
/// - Parameters for outer joins must be first - as sequence of parameters changes
/// </pre>*/
/// </summary>
/// <param name="sqlStatement">sqlStatement</param>
/// <returns>converted statement</returns>
protected String ConvertOuterJoin(String sqlStatement)
{
bool trace = false;
//
int fromIndex = Util.FindIndexOf(sqlStatement.ToUpper(), " FROM ");
int whereIndex = Util.FindIndexOf(sqlStatement.ToUpper(), " WHERE ");
//begin vpj-cd e-evolution 03/14/2005 PostgreSQL
//int endWhereIndex = Util.findIndexOf(sqlStatement.toUpperCase(), " GRPUP BY ");
int endWhereIndex = Util.FindIndexOf(sqlStatement.ToUpper(), " GROUP BY ");
//end vpj-cd e-evolution 03/14/2005 PostgreSQL
if (endWhereIndex == -1)
{
endWhereIndex = Util.FindIndexOf(sqlStatement.ToUpper(), " ORDER BY ");
}
if (endWhereIndex == -1)
{
endWhereIndex = sqlStatement.Length;
}
//
if (trace)
{
log.Info("OuterJoin<== " + sqlStatement);
// log.info("From=" + fromIndex + ", Where=" + whereIndex + ", End=" + endWhereIndex + ", Length=" + sqlStatement.length());
}
//
String selectPart = sqlStatement.Substring(0, fromIndex);
String fromPart = sqlStatement.Substring(fromIndex, whereIndex);
String wherePart = sqlStatement.Substring(whereIndex, endWhereIndex);
String rest = sqlStatement.Substring(endWhereIndex);
// find/remove all (+) from WHERE clase ------------------------------
String newWherePart = wherePart;
List <String> joins = new List <String>();
int pos = newWherePart.IndexOf("(+)");
while (pos != -1)
{
// find starting point
int start = newWherePart.LastIndexOf(" AND ", pos);
int startOffset = 5;
if (start == -1)
{
start = newWherePart.LastIndexOf(" OR ", pos);
startOffset = 4;
}
if (start == -1)
{
start = newWherePart.LastIndexOf("WHERE ", pos);
startOffset = 6;
}
if (start == -1)
{
String error = "Start point not found in clause " + wherePart;
log.Severe(error);
m_conversionError = error;
return(sqlStatement);
}
// find end point
int end = newWherePart.IndexOf(" AND ", pos);
if (end == -1)
{
end = newWherePart.IndexOf(" OR ", pos);
}
if (end == -1)
{
end = newWherePart.Length;
}
// log.info("<= " + newWherePart + " - Start=" + start + "+" + startOffset + ", End=" + end);
// extract condition
String condition = newWherePart.Substring(start + startOffset, end);
joins.Add(condition);
if (trace)
{
log.Info("->" + condition);
}
// new WHERE clause
newWherePart = newWherePart.Substring(0, start) + newWherePart.Substring(end);
// log.info("=> " + newWherePart);
//
pos = newWherePart.IndexOf("(+)");
}
// correct beginning
newWherePart = newWherePart.Trim();
if (newWherePart.StartsWith("AND "))
{
newWherePart = "WHERE" + newWherePart.Substring(3);
}
else if (newWherePart.StartsWith("OR "))
{
newWherePart = "WHERE" + newWherePart.Substring(2);
}
if (trace)
{
log.Info("=> " + newWherePart);
}
// Correct FROM clause -----------------------------------------------
// Disassemble FROM
String[] fromParts = fromPart.Trim().Substring(4).Split(',');
Dictionary <String, String> fromAlias = new Dictionary <String, String>(); // tables to be processed
Dictionary <String, String> fromLookup = new Dictionary <String, String>(); // used tabled
for (int i = 0; i < fromParts.Length; i++)
{
String entry = fromParts[i].Trim();
String alias = entry; // no alias
String table = entry;
int aPos = entry.LastIndexOf(' ');
if (aPos != -1)
{
alias = entry.Substring(aPos + 1);
table = entry.Substring(0, entry.IndexOf(' ')); // may have AS
}
fromAlias.Add(alias, table);
fromLookup.Add(alias, table);
if (trace)
{
log.Info("Alias=" + alias + ", Table=" + table);
}
}
/** Single column
* SELECT t.TableName, w.Name FROM AD_Table t, AD_Window w
* WHERE t.AD_Window_ID=w.AD_Window_ID(+)
* -- 275 rows
* SELECT t.TableName, w.Name FROM AD_Table t
* LEFT OUTER JOIN AD_Window w ON (t.AD_Window_ID=w.AD_Window_ID)
*
* SELECT t.TableName, w.Name FROM AD_Table t, AD_Window w
* WHERE t.AD_Window_ID(+)=w.AD_Window_ID
* -- 239 rows
* SELECT t.TableName, w.Name FROM AD_Table t
* RIGHT OUTER JOIN AD_Window w ON (t.AD_Window_ID=w.AD_Window_ID)
*
** Multiple columns
** SELECT tn.Node_ID,tn.Parent_ID,tn.SeqNo,tb.IsActive
** FROM AD_TreeNode tn, AD_TreeBar tb
** WHERE tn.AD_Tree_ID=tb.AD_Tree_ID(+) AND tn.Node_ID=tb.Node_ID(+)
** AND tn.AD_Tree_ID=10
** -- 235 rows
** SELECT tn.Node_ID,tn.Parent_ID,tn.SeqNo,tb.IsActive
** FROM AD_TreeNode tn LEFT OUTER JOIN AD_TreeBar tb
** ON (tn.Node_ID=tb.Node_ID AND tn.AD_Tree_ID=tb.AD_Tree_ID AND tb.AD_User_ID=0)
** WHERE tn.AD_Tree_ID=10
**
** SELECT tn.Node_ID,tn.Parent_ID,tn.SeqNo,tb.IsActive
** FROM AD_TreeNode tn, AD_TreeBar tb
** WHERE tn.AD_Tree_ID=tb.AD_Tree_ID(+) AND tn.Node_ID=tb.Node_ID(+)
** AND tn.AD_Tree_ID=10 AND tb.AD_User_ID(+)=0
** -- 214 rows
** SELECT tn.Node_ID,tn.Parent_ID,tn.SeqNo,tb.IsActive
** FROM AD_TreeNode tn LEFT OUTER JOIN AD_TreeBar tb
** ON (tn.Node_ID=tb.Node_ID AND tn.AD_Tree_ID=tb.AD_Tree_ID AND tb.AD_User_ID=0)
** WHERE tn.AD_Tree_ID=10
**
*/
StringBuilder newFrom = new StringBuilder();
for (int i = 0; i < joins.Count; i++)
{
Join first = new Join(joins[i]);
first.SetMainTable(fromLookup[first.GetMainAlias()]);
fromAlias.Remove(first.GetMainAlias()); // remove from list
first.SetJoinTable(fromLookup[first.GetJoinAlias()]);
fromAlias.Remove(first.GetJoinAlias()); // remove from list
if (trace)
{
log.Info("-First: " + first);
}
//
if (newFrom.Length == 0)
{
newFrom.Append(" FROM ");
}
else
{
newFrom.Append(", ");
}
newFrom.Append(first.GetMainTable()).Append(" ").Append(first.GetMainAlias())
.Append(first.IsLeft() ? " LEFT" : " RIGHT").Append(" OUTER JOIN ")
.Append(first.GetJoinTable()).Append(" ").Append(first.GetJoinAlias())
.Append(" ON (").Append(first.GetCondition());
// keep it open - check for other key comparisons
for (int j = i + 1; j < joins.Count; j++)
{
Join second = new Join(joins[j]);
second.SetMainTable(fromLookup[second.GetMainAlias()]);
second.SetJoinTable(fromLookup[second.GetJoinAlias()]);
if ((first.GetMainTable().Equals(second.GetMainTable()) &&
first.GetJoinTable().Equals(second.GetJoinTable())) ||
second.IsConditionOf(first))
{
if (trace)
{
log.Info("-Second/key: " + second);
}
newFrom.Append(" AND ").Append(second.GetCondition());
joins.RemoveAt(j); // remove from join list
fromAlias.Remove(first.GetJoinAlias()); // remove from table list
//----
for (int k = i + 1; k < joins.Count; k++)
{
Join third = new Join(joins[k]);
third.SetMainTable(fromLookup[third.GetMainAlias()]);
third.SetJoinTable(fromLookup[third.GetJoinAlias()]);
if (third.IsConditionOf(second))
{
if (trace)
{
log.Info("-Third/key: " + third);
}
newFrom.Append(" AND ").Append(third.GetCondition());
joins.RemoveAt(k); // remove from join list
fromAlias.Remove(third.GetJoinAlias()); // remove from table list
}
else if (trace)
{
log.Info("-Third/key-skip: " + third);
}
}
}
else if (trace)
{
log.Info("-Second/key-skip: " + second);
}
}
newFrom.Append(")"); // close ON
// check dependency on first table
for (int j = i + 1; j < joins.Count; j++)
{
Join second = new Join(joins[j]);
second.SetMainTable(fromLookup[second.GetMainAlias()]);
second.SetJoinTable(fromLookup[second.GetJoinAlias()]);
if (first.GetMainTable().Equals(second.GetMainTable()))
{
if (trace)
{
log.Info("-Second/dep: " + second);
}
// FROM (AD_Field f LEFT OUTER JOIN AD_Column c ON (f.AD_Column_ID = c.AD_Column_ID))
// LEFT OUTER JOIN AD_FieldGroup fg ON (f.AD_FieldGroup_ID = fg.AD_FieldGroup_ID),
newFrom.Insert(6, '('); // _FROM ...
newFrom.Append(')'); // add parantesis on previous relation
//
newFrom.Append(second.IsLeft() ? " LEFT" : " RIGHT").Append(" OUTER JOIN ")
.Append(second.GetJoinTable()).Append(" ").Append(second.GetJoinAlias())
.Append(" ON (").Append(second.GetCondition());
joins.RemoveAt(j); // remove from join list
fromAlias.Remove(second.GetJoinAlias()); // remove from table list
// additional join colums would come here
newFrom.Append(")"); // close ON
//----
for (int k = i + 1; k < joins.Count; k++)
{
Join third = new Join(joins[k]);
third.SetMainTable(fromLookup[third.GetMainAlias()]);
third.SetJoinTable(fromLookup[third.GetJoinAlias()]);
if (second.GetJoinTable().Equals(third.GetMainTable()))
{
if (trace)
{
log.Info("-Third-dep: " + third);
}
// FROM ((C_BPartner p LEFT OUTER JOIN AD_User c ON (p.C_BPartner_ID=c.C_BPartner_ID))
// LEFT OUTER JOIN C_BPartner_Location l ON (p.C_BPartner_ID=l.C_BPartner_ID))
// LEFT OUTER JOIN C_Location a ON (l.C_Location_ID=a.C_Location_ID)
newFrom.Insert(6, '('); // _FROM ...
newFrom.Append(')'); // add parantesis on previous relation
//
newFrom.Append(third.IsLeft() ? " LEFT" : " RIGHT").Append(" OUTER JOIN ")
.Append(third.GetJoinTable()).Append(" ").Append(third.GetJoinAlias())
.Append(" ON (").Append(third.GetCondition());
joins.RemoveAt(k); // remove from join list
fromAlias.Remove(third.GetJoinAlias()); // remove from table list
// additional join colums would come here
newFrom.Append(")"); // close ON
}
else if (trace)
{
log.Info("-Third-skip: " + third);
}
}
}
else if (trace)
{
log.Info("-Second/dep-skip: " + second);
}
} // dependency on first table
}
// remaining Tables
var it = fromAlias.Keys.GetEnumerator();
while (it.MoveNext())
{
String alias = it.Current;
Object table = fromAlias[alias];
newFrom.Append(", ").Append(table);
if (!table.Equals(alias))
{
newFrom.Append(" ").Append(alias);
}
}
if (trace)
{
log.Info(newFrom.ToString());
}
//
StringBuilder retValue = new StringBuilder(sqlStatement.Length + 20);
retValue.Append(selectPart)
.Append(newFrom).Append(" ")
.Append(newWherePart).Append(rest);
//
if (trace)
{
log.Info("OuterJoin==> " + retValue.ToString());
}
return(retValue.ToString());
}
