public void IdentifyMappingTable(List <ForeignKey> fkList, Tables tables, bool checkForFkNameClashes, bool includeSchema)
{
IsMapping = false;
var nonReadOnlyColumns = Columns
.Where(c => !c.IsIdentity && !c.IsRowVersion && !c.IsStoreGenerated && !c.Hidden)
.ToList();
// Ignoring read-only columns, it must have only 2 columns to be a mapping table
if (nonReadOnlyColumns.Count != 2)
{
return;
}
// Must have 2 primary keys
if (nonReadOnlyColumns.Count(x => x.IsPrimaryKey) != 2)
{
return;
}
// No columns should be nullable
if (nonReadOnlyColumns.Any(x => x.IsNullable))
{
return;
}
// Find the foreign keys for this table
var foreignKeys = fkList.Where(x =>
string.Compare(x.FkTableName, DbName, StringComparison.OrdinalIgnoreCase) == 0 &&
string.Compare(x.FkSchema, Schema.DbName, StringComparison.OrdinalIgnoreCase) == 0)
.ToList();
// Each column must have a foreign key, therefore check column and foreign key counts match
if (foreignKeys.Select(x => x.FkColumn).Distinct().Count() != 2)
{
return;
}
var left = foreignKeys[0];
var right = foreignKeys[1];
if (!left.IncludeReverseNavigation || !right.IncludeReverseNavigation)
{
return;
}
var leftTable = tables.GetTable(left.PkTableName, left.PkSchema);
if (leftTable == null)
{
return;
}
var rightTable = tables.GetTable(right.PkTableName, right.PkSchema);
if (rightTable == null)
{
return;
}
var leftPropName = leftTable.GetUniqueColumnName(true, rightTable.NameHumanCase, right, checkForFkNameClashes, false, Relationship.ManyToOne); // relationship from the mapping table to each side is Many-to-One
leftPropName = _filter.MappingTableRename(DbName, leftTable.NameHumanCase, leftPropName);
var rightPropName = rightTable.GetUniqueColumnName(false, leftTable.NameHumanCase, left, checkForFkNameClashes, false, Relationship.ManyToOne); // relationship from the mapping table to each side is Many-to-One
rightPropName = _filter.MappingTableRename(DbName, rightTable.NameHumanCase, rightPropName);
leftTable.AddMappingConfiguration(left, right, leftPropName, rightPropName, includeSchema);
IsMapping = true;
rightTable.AddReverseNavigation(Relationship.ManyToMany, leftTable, rightPropName, null, null, this);
leftTable.AddReverseNavigation(Relationship.ManyToMany, rightTable, leftPropName, null, null, this);
}
