/// <summary>
/// Generate the SQL DELETE that deletes all rows
/// </summary>
/// <returns></returns>
protected override SqlString GenerateDeleteString()
{
SqlDeleteBuilder delete = new SqlDeleteBuilder(factory)
.SetTableName(qualifiedTableName)
.SetIdentityColumn(KeyColumnNames, KeyType);
if (HasWhere)
{
delete.AddWhereFragment(sqlWhereString);
}
return(delete.ToSqlString());
}
// Generate all the SQL
/// <summary>
/// Generate the SQL that deletes a row by id (and version)
/// </summary>
/// <returns>A SqlString for a Delete</returns>
protected virtual SqlString GenerateDeleteString()
{
SqlDeleteBuilder deleteBuilder = new SqlDeleteBuilder(factory);
deleteBuilder.SetTableName(TableName)
.SetIdentityColumn(IdentifierColumnNames, IdentifierType);
if (IsVersioned)
{
deleteBuilder.SetVersionColumn(new string[] { VersionColumnName }, VersionType);
}
return(deleteBuilder.ToSqlString());
}
/// <summary>
/// Generate the SQL DELETE that deletes a particular row
/// </summary>
/// <returns></returns>
protected override SqlString GenerateDeleteRowString()
{
SqlDeleteBuilder delete = new SqlDeleteBuilder(factory);
delete.SetTableName(qualifiedTableName);
if (hasIdentifier)
{
delete.AddWhereFragment(rowSelectColumnNames, rowSelectType, " = ");
}
else
{
delete.AddWhereFragment(KeyColumnNames, KeyType, " = ")
.AddWhereFragment(rowSelectColumnNames, rowSelectType, " = ");
}
return(delete.ToSqlString());
}
public MultiTableDeleteExecutor(IStatement statement)
: base(statement, log)
{
if (!Factory.Dialect.SupportsTemporaryTables)
{
throw new HibernateException("cannot perform multi-table deletes using dialect not supporting temp tables");
}
var deleteStatement = (DeleteStatement)statement;
FromElement fromElement = deleteStatement.FromClause.GetFromElement();
string bulkTargetAlias = fromElement.TableAlias;
persister = fromElement.Queryable;
idInsertSelect = GenerateIdInsertSelect(persister, bulkTargetAlias, deleteStatement.WhereClause);
log.Debug("Generated ID-INSERT-SELECT SQL (multi-table delete) : {0}", idInsertSelect);
string[] tableNames = persister.ConstraintOrderedTableNameClosure;
string[][] columnNames = persister.ConstraintOrderedTableKeyColumnClosure;
string idSubselect = GenerateIdSubselect(persister);
deletes = new SqlString[tableNames.Length];
for (int i = tableNames.Length - 1; i >= 0; i--)
{
// TODO : an optimization here would be to consider cascade deletes and not gen those delete statements;
// the difficulty is the ordering of the tables here vs the cascade attributes on the persisters ->
// the table info gotten here should really be self-contained (i.e., a class representation
// defining all the needed attributes), then we could then get an array of those
SqlDeleteBuilder delete = new SqlDeleteBuilder(Factory.Dialect, Factory)
.SetTableName(tableNames[i])
.SetWhere("(" + string.Join(", ", columnNames[i]) + ") IN (" + idSubselect + ")");
if (Factory.Settings.IsCommentsEnabled)
{
delete.SetComment("bulk delete");
}
deletes[i] = delete.ToSqlString();
}
}
