quote.py

SQLAlchemy. 经典的Python ORM框架。学习必看。

import testenv; testenv.configure_for_tests()
from sqlalchemy import *
from sqlalchemy import sql
from sqlalchemy.sql import compiler
from testlib import *

class QuoteTest(TestBase):
    def setUpAll(self):
        # TODO: figure out which databases/which identifiers allow special characters to be used,
        # such as:  spaces, quote characters, punctuation characters, set up tests for those as
        # well.
        global table1, table2, table3
        metadata = MetaData(testing.db)
        table1 = Table('WorstCase1', metadata,
            Column('lowercase', Integer, primary_key=True),
            Column('UPPERCASE', Integer),
            Column('MixedCase', Integer),
            Column('ASC', Integer, key='a123'))
        table2 = Table('WorstCase2', metadata,
            Column('desc', Integer, primary_key=True, key='d123'),
            Column('Union', Integer, key='u123'),
            Column('MixedCase', Integer))
        table1.create()
        table2.create()

    def tearDown(self):
        table1.delete().execute()
        table2.delete().execute()

    def tearDownAll(self):
        table1.drop()
        table2.drop()

    def testbasic(self):
        table1.insert().execute({'lowercase':1,'UPPERCASE':2,'MixedCase':3,'a123':4},
                {'lowercase':2,'UPPERCASE':2,'MixedCase':3,'a123':4},
                {'lowercase':4,'UPPERCASE':3,'MixedCase':2,'a123':1})
        table2.insert().execute({'d123':1,'u123':2,'MixedCase':3},
                {'d123':2,'u123':2,'MixedCase':3},
                {'d123':4,'u123':3,'MixedCase':2})

        res1 = select([table1.c.lowercase, table1.c.UPPERCASE, table1.c.MixedCase, table1.c.a123]).execute().fetchall()
        print res1
        assert(res1==[(1,2,3,4),(2,2,3,4),(4,3,2,1)])

        res2 = select([table2.c.d123, table2.c.u123, table2.c.MixedCase]).execute().fetchall()
        print res2
        assert(res2==[(1,2,3),(2,2,3),(4,3,2)])

    def testreflect(self):
        meta2 = MetaData(testing.db)
        t2 = Table('WorstCase2', meta2, autoload=True, quote=True)
        assert 'MixedCase' in t2.c

    def testlabels(self):
        table1.insert().execute({'lowercase':1,'UPPERCASE':2,'MixedCase':3,'a123':4},
                {'lowercase':2,'UPPERCASE':2,'MixedCase':3,'a123':4},
                {'lowercase':4,'UPPERCASE':3,'MixedCase':2,'a123':1})
        table2.insert().execute({'d123':1,'u123':2,'MixedCase':3},
                {'d123':2,'u123':2,'MixedCase':3},
                {'d123':4,'u123':3,'MixedCase':2})

        res1 = select([table1.c.lowercase, table1.c.UPPERCASE, table1.c.MixedCase, table1.c.a123], use_labels=True).execute().fetchall()
        print res1
        assert(res1==[(1,2,3,4),(2,2,3,4),(4,3,2,1)])

        res2 = select([table2.c.d123, table2.c.u123, table2.c.MixedCase], use_labels=True).execute().fetchall()
        print res2
        assert(res2==[(1,2,3),(2,2,3),(4,3,2)])

    @testing.unsupported('oracle')
    def testlabels(self):
        """test the quoting of labels.

        if labels arent quoted, a query in postgres in particular will fail since it produces:

        SELECT LaLa.lowercase, LaLa."UPPERCASE", LaLa."MixedCase", LaLa."ASC"
        FROM (SELECT DISTINCT "WorstCase1".lowercase AS lowercase, "WorstCase1"."UPPERCASE" AS UPPERCASE, "WorstCase1"."MixedCase" AS MixedCase, "WorstCase1"."ASC" AS ASC \nFROM "WorstCase1") AS LaLa

        where the "UPPERCASE" column of "LaLa" doesnt exist.
        """
        x = table1.select(distinct=True).alias("LaLa").select().scalar()

    def testlabels2(self):
        metadata = MetaData()
        table = Table("ImATable", metadata,
            Column("col1", Integer))
        x = select([table.c.col1.label("ImATable_col1")]).alias("SomeAlias")
        assert str(select([x.c.ImATable_col1])) == '''SELECT "SomeAlias"."ImATable_col1" \nFROM (SELECT "ImATable".col1 AS "ImATable_col1" \nFROM "ImATable") AS "SomeAlias"'''

        # note that 'foo' and 'FooCol' are literals already quoted
        x = select([sql.literal_column("'foo'").label("somelabel")], from_obj=[table]).alias("AnAlias")
        x = x.select()
        assert str(x) == '''SELECT "AnAlias".somelabel \nFROM (SELECT 'foo' AS somelabel \nFROM "ImATable") AS "AnAlias"'''

        x = select([sql.literal_column("'FooCol'").label("SomeLabel")], from_obj=[table])
        x = x.select()
        assert str(x) == '''SELECT "SomeLabel" \nFROM (SELECT 'FooCol' AS "SomeLabel" \nFROM "ImATable")'''


class PreparerTest(TestBase):
    """Test the db-agnostic quoting services of IdentifierPreparer."""

    def test_unformat(self):
        prep = compiler.IdentifierPreparer(None)
        unformat = prep.unformat_identifiers

        def a_eq(have, want):
            if have != want:
                print "Wanted %s" % want
                print "Received %s" % have
            self.assert_(have == want)

        a_eq(unformat('foo'), ['foo'])
        a_eq(unformat('"foo"'), ['foo'])
        a_eq(unformat("'foo'"), ["'foo'"])
        a_eq(unformat('foo.bar'), ['foo', 'bar'])
        a_eq(unformat('"foo"."bar"'), ['foo', 'bar'])
        a_eq(unformat('foo."bar"'), ['foo', 'bar'])
        a_eq(unformat('"foo".bar'), ['foo', 'bar'])
        a_eq(unformat('"foo"."b""a""r"."baz"'), ['foo', 'b"a"r', 'baz'])

    def test_unformat_custom(self):
        class Custom(compiler.IdentifierPreparer):
            def __init__(self, dialect):
                super(Custom, self).__init__(dialect, initial_quote='`',
                                             final_quote='`')
            def _escape_identifier(self, value):
                return value.replace('`', '``')
            def _unescape_identifier(self, value):
                return value.replace('``', '`')

        prep = Custom(None)
        unformat = prep.unformat_identifiers

        def a_eq(have, want):
            if have != want:
                print "Wanted %s" % want
                print "Received %s" % have
            self.assert_(have == want)

        a_eq(unformat('foo'), ['foo'])
        a_eq(unformat('`foo`'), ['foo'])
        a_eq(unformat(`'foo'`), ["'foo'"])
        a_eq(unformat('foo.bar'), ['foo', 'bar'])
        a_eq(unformat('`foo`.`bar`'), ['foo', 'bar'])
        a_eq(unformat('foo.`bar`'), ['foo', 'bar'])
        a_eq(unformat('`foo`.bar'), ['foo', 'bar'])
        a_eq(unformat('`foo`.`b``a``r`.`baz`'), ['foo', 'b`a`r', 'baz'])

if __name__ == "__main__":
    testenv.main()