private static bool BuildShortestPath(ref List <SqlRelationAttribute> res, RelationPath paths, Func <string, string, bool> isDestination, string previousSchema, string previousTable)
{
foreach (var nextPath in paths.NextPaths)
{
if (isDestination(nextPath.Schema, nextPath.Table))
{
res.Insert(0, nextPath.SqlRelation);
return(true);
}
var foundWanted = BuildShortestPath(ref res, nextPath, isDestination, paths.Schema, paths.Table);
if (foundWanted)
{
//check if relation needs to be turned around, fex. 'gebouw -> terrobj <- tobjhnr', should be 'gebouw -> terrobj -> tobjhnr'
if (nextPath.SqlRelation.SelfSchema == paths.Schema && nextPath.SqlRelation.SelfTable == paths.Table)
{
res.Insert(0, nextPath.SqlRelation);
}
else
{
res.Insert(0, nextPath.SqlRelation.CreateReverse());
}
return(true);
}
}
return(false);
}
public void AddNextPath(RelationPath nextPath)
{
if (nextPath != null)
{
_NextPaths.Add(nextPath);
}
}
private static RelationPath BuildPathsTo(RelationPath path, string currentSchema, string currentTable, Func <string, string, bool> isDestination, string previousSchema, string previousTable, IEnumerable <SqlRelationAttribute> blacklist, List <string> usedPaths)
{
if (usedPaths == null)
{
usedPaths = new List <string>();
}
if (path == null)
{
path = new RelationPath();
}
path.Schema = currentSchema;
path.Table = currentTable;
var relationsFrom = GetRelationsFrom(currentSchema, currentTable);
var relationsTo = GetRelationsTo(currentSchema, currentTable);
foreach (var relation in relationsFrom)
{
//illegal paths
if (blacklist != null && blacklist.Contains(relation))
{
continue;
}
//when you go down the rabbit hole... no turning backsies
dynamic currentPath = relation.ToString();
if (usedPaths.Contains(currentPath))
{
continue;
}
usedPaths.Add(currentPath);
//are we there yet?
if (isDestination(relation.OtherSchema, relation.OtherTable))
{
//yes!
RelationPath nextPath = new RelationPath();
nextPath.PreviousPath = path;
nextPath.Schema = relation.OtherSchema;
nextPath.Table = relation.OtherTable;
nextPath.SqlRelation = relation;
path.AddNextPath(nextPath);
//Return path
}
else
{
//no :( go further down the hole
RelationPath nextPath = new RelationPath();
nextPath.PreviousPath = path;
nextPath.SqlRelation = relation;
nextPath = BuildPathsTo(nextPath, relation.OtherSchema, relation.OtherTable, isDestination, currentSchema, currentTable, blacklist, usedPaths);
path.AddNextPath(nextPath);
}
}
foreach (var relation in relationsTo)
{
//illegal paths
if (blacklist != null && blacklist.Contains(relation))
{
continue;
}
//when you go down the rabbit hole... no turning back
var currentPath = relation.ToString();
if (usedPaths.Contains(currentPath))
{
continue;
}
usedPaths.Add(currentPath);
//are we there yet?
if (isDestination(relation.SelfSchema, relation.SelfTable))
{
//yes!
RelationPath nextPath = new RelationPath();
nextPath.PreviousPath = path;
nextPath.Schema = relation.SelfSchema;
nextPath.Table = relation.SelfTable;
nextPath.SqlRelation = relation;
path.AddNextPath(nextPath);
//Return path
}
else
{
//no :( go further down the hole
RelationPath nextPath = new RelationPath();
nextPath.PreviousPath = path;
nextPath.SqlRelation = relation;
nextPath = BuildPathsTo(nextPath, relation.SelfSchema, relation.SelfTable, isDestination, currentSchema, currentTable, blacklist, usedPaths);
path.AddNextPath(nextPath);
}
}
return(path);
}
private static RelationPath BuildPathsTo(RelationPath path, string currentSchema, string currentTable, string wantedSchema, string wantedTable, string previousSchema, string previousTable, IEnumerable <SqlRelationAttribute> blacklist, List <string> usedPaths)
{
return(BuildPathsTo(path, currentSchema, currentTable, (schema, table) => schema == wantedSchema && table == wantedTable, previousSchema, previousTable, blacklist, usedPaths));
}
private static bool BuildShortestPath(ref List <SqlRelationAttribute> res, RelationPath paths, string wantedSchema, string wantedTable, string previousSchema, string previousTable)
{
return(BuildShortestPath(ref res, paths, (schema, table) => schema == wantedSchema && table == wantedTable, previousSchema, previousTable));
}
