public Table evaluate() throws DatabaseException {
DatabaseQueryContext context = new DatabaseQueryContext(database);
if (type.equals("create")) {
// Does the user have privs to create this tables?
if (!database.getDatabase().canUserCreateTableObject(context, user, vname)) {
throw new UserAccessException("User not permitted to create view: " + view_name);
}
// Does the schema exist?
boolean ignore_case = database.isInCaseInsensitiveMode();
SchemaDef schema = database.resolveSchemaCase(vname.getSchema(), ignore_case);
if (schema == null) {
throw new DatabaseException("Schema '" + vname.getSchema() + "' doesn't exist.");
} else {
vname = new TableName(schema.getName(), vname.getName());
}
// Check the permissions for this user to select from the tables in the
// given plan.
Select.checkUserSelectPermissions(context, user, plan);
// Does the table already exist?
if (database.tableExists(vname)) {
throw new DatabaseException("View or table with name '" + vname + "' already exists.");
}
// Before evaluation, make a clone of the plan,
QueryPlanNode plan_copy;
try {
plan_copy = (QueryPlanNode) plan.clone();
} catch (CloneNotSupportedException e) {
Debug().writeException(e);
throw new DatabaseException("Clone error: " + e.getMessage());
}
// We have to execute the plan to get the DataTableDef that represents the
// result of the view execution.
Table t = plan.evaluate(context);
DataTableDef data_table_def = new DataTableDef(t.getDataTableDef());
data_table_def.setTableName(vname);
// Create a ViewDef object,
ViewDef view_def = new ViewDef(data_table_def, plan_copy);
// And create the view object,
database.createView(query, view_def);
// The initial grants for a view is to give the user who created it
// full access.
database
.getGrantManager()
.addGrant(
Privileges.TABLE_ALL_PRIVS,
GrantManager.TABLE,
vname.toString(),
user.getUserName(),
true,
Database.INTERNAL_SECURE_USERNAME);
} else if (type.equals("drop")) {
// Does the user have privs to drop this tables?
if (!database.getDatabase().canUserDropTableObject(context, user, vname)) {
throw new UserAccessException("User not permitted to drop view: " + view_name);
}
// Drop the view object
database.dropView(vname);
// Drop the grants for this object
database.getGrantManager().revokeAllGrantsOnObject(GrantManager.TABLE, vname.toString());
} else {
throw new Error("Unknown view command type: " + type);
}
return FunctionTable.resultTable(context, 0);
}
