diff options
Diffstat (limited to 'lib/sql.py')
| -rw-r--r-- | lib/sql.py | 46 |
1 files changed, 38 insertions, 8 deletions
@@ -290,7 +290,7 @@ class SQL(Composable): class Identifier(Composable): """ - A `Composable` representing an SQL identifer. + A `Composable` representing an SQL identifer or a dot-separated sequence. Identifiers usually represent names of database objects, such as tables or fields. PostgreSQL identifiers follow `different rules`__ than SQL string @@ -307,20 +307,50 @@ class Identifier(Composable): >>> print(sql.SQL(', ').join([t1, t2, t3]).as_string(conn)) "foo", "ba'r", "ba""z" + Multiple strings can be passed to the object to represent a qualified name, + i.e. a dot-separated sequence of identifiers. + + Example:: + + >>> query = sql.SQL("select {} from {}").format( + ... sql.Identifier("table", "field"), + ... sql.Identifier("schema", "table")) + >>> print(query.as_string(conn)) + select "table"."field" from "schema"."table" + """ - def __init__(self, string): - if not isinstance(string, string_types): - raise TypeError("SQL identifiers must be strings") + def __init__(self, *strings): + if not strings: + raise TypeError("Identifier cannot be empty") + + for s in strings: + if not isinstance(s, string_types): + raise TypeError("SQL identifier parts must be strings") - super(Identifier, self).__init__(string) + super(Identifier, self).__init__(strings) @property - def string(self): - """The string wrapped by the `Identifier`.""" + def strings(self): + """A tuple with the strings wrapped by the `Identifier`.""" return self._wrapped + @property + def string(self): + """The string wrapped by the `Identifier`. + """ + if len(self._wrapped) == 1: + return self._wrapped[0] + else: + raise AttributeError( + "the Identifier wraps more than one than one string") + + def __repr__(self): + return "%s(%s)" % ( + self.__class__.__name__, + ', '.join(map(repr, self._wrapped))) + def as_string(self, context): - return ext.quote_ident(self._wrapped, context) + return '.'.join(ext.quote_ident(s, context) for s in self._wrapped) class Literal(Composable): |