本文整理汇总了Python中sqlalchemy.sql.expression.FunctionElement方法的典型用法代码示例。如果您正苦于以下问题：Python expression.FunctionElement方法的具体用法？Python expression.FunctionElement怎么用？Python expression.FunctionElement使用的例子？那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类sqlalchemy.sql.expression的用法示例。
在下文中一共展示了expression.FunctionElement方法的8个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Python代码示例。
示例1: test_conn_execute
# 需要导入模块: from sqlalchemy.sql import expression [as 别名]
# 或者: from sqlalchemy.sql.expression import FunctionElement [as 别名]
def test_conn_execute(self, connection):
from sqlalchemy.sql.expression import FunctionElement
from sqlalchemy.ext.compiler import compiles
class myfunc(FunctionElement):
type = Date()
@compiles(myfunc)
def compile_(elem, compiler, **kw):
return compiler.process(func.current_date())
x = connection.execute(func.current_date()).scalar()
y = connection.execute(func.current_date().select()).scalar()
z = connection.scalar(func.current_date())
q = connection.scalar(myfunc())
assert (x == y == z == q) is True 示例2: test_functions
# 需要导入模块: from sqlalchemy.sql import expression [as 别名]
# 或者: from sqlalchemy.sql.expression import FunctionElement [as 别名]
def test_functions(self):
from sqlalchemy.dialects import postgresql
class MyUtcFunction(FunctionElement):
pass
@compiles(MyUtcFunction)
def visit_myfunc(element, compiler, **kw):
return "utcnow()"
@compiles(MyUtcFunction, "postgresql")
def visit_myfunc_pg(element, compiler, **kw):
return "timezone('utc', current_timestamp)"
self.assert_compile(
MyUtcFunction(), "utcnow()", use_default_dialect=True
)
self.assert_compile(
MyUtcFunction(),
"timezone('utc', current_timestamp)",
dialect=postgresql.dialect(),
) 示例3: test_function_subclasses_one
# 需要导入模块: from sqlalchemy.sql import expression [as 别名]
# 或者: from sqlalchemy.sql.expression import FunctionElement [as 别名]
def test_function_subclasses_one(self):
class Base(FunctionElement):
name = "base"
class Sub1(Base):
name = "sub1"
class Sub2(Base):
name = "sub2"
@compiles(Base)
def visit_base(element, compiler, **kw):
return element.name
@compiles(Sub1)
def visit_sub1(element, compiler, **kw):
return "FOO" + element.name
self.assert_compile(
select([Sub1(), Sub2()]),
"SELECT FOOsub1 AS sub1_1, sub2 AS sub2_1",
use_default_dialect=True,
) 示例4: test_use_labels_function_element
# 需要导入模块: from sqlalchemy.sql import expression [as 别名]
# 或者: from sqlalchemy.sql.expression import FunctionElement [as 别名]
def test_use_labels_function_element(self):
from sqlalchemy.ext.compiler import compiles
class max_(FunctionElement):
name = "max"
@compiles(max_)
def visit_max(element, compiler, **kw):
return "max(%s)" % compiler.process(element.clauses, **kw)
self.assert_compile(
select([max_(5, 6)], use_labels=True),
"SELECT max(:max_2, :max_3) AS max_1",
) 示例5: test_incorrect_none_type
# 需要导入模块: from sqlalchemy.sql import expression [as 别名]
# 或者: from sqlalchemy.sql.expression import FunctionElement [as 别名]
def test_incorrect_none_type(self):
from sqlalchemy.sql.expression import FunctionElement
class MissingType(FunctionElement):
name = "mt"
type = None
assert_raises_message(
TypeError,
"Object None associated with '.type' attribute is "
"not a TypeEngine class or object",
lambda: column("x", MissingType()) == 5,
) 示例6: test_function_element_column_labels
# 需要导入模块: from sqlalchemy.sql import expression [as 别名]
# 或者: from sqlalchemy.sql.expression import FunctionElement [as 别名]
def test_function_element_column_labels(self):
users = self.tables.users
sess = Session()
class max_(expression.FunctionElement):
name = "max"
@compiles(max_)
def visit_max(element, compiler, **kw):
return "max(%s)" % compiler.process(element.clauses, **kw)
q = sess.query(max_(users.c.id))
eq_(q.all(), [(10,)]) 示例7: test_function_calls_base
# 需要导入模块: from sqlalchemy.sql import expression [as 别名]
# 或者: from sqlalchemy.sql.expression import FunctionElement [as 别名]
def test_function_calls_base(self):
from sqlalchemy.dialects import mssql
class greatest(FunctionElement):
type = Numeric()
name = "greatest"
@compiles(greatest)
def default_greatest(element, compiler, **kw):
return compiler.visit_function(element)
@compiles(greatest, "mssql")
def case_greatest(element, compiler, **kw):
arg1, arg2 = list(element.clauses)
return "CASE WHEN %s > %s THEN %s ELSE %s END" % (
compiler.process(arg1),
compiler.process(arg2),
compiler.process(arg1),
compiler.process(arg2),
)
self.assert_compile(
greatest("a", "b"),
"greatest(:greatest_1, :greatest_2)",
use_default_dialect=True,
)
self.assert_compile(
greatest("a", "b"),
"CASE WHEN :greatest_1 > :greatest_2 "
"THEN :greatest_1 ELSE :greatest_2 END",
dialect=mssql.dialect(),
) 示例8: test_function_subclasses_two
# 需要导入模块: from sqlalchemy.sql import expression [as 别名]
# 或者: from sqlalchemy.sql.expression import FunctionElement [as 别名]
def test_function_subclasses_two(self):
class Base(FunctionElement):
name = "base"
class Sub1(Base):
name = "sub1"
@compiles(Base)
def visit_base(element, compiler, **kw):
return element.name
class Sub2(Base):
name = "sub2"
class SubSub1(Sub1):
name = "subsub1"
self.assert_compile(
select([Sub1(), Sub2(), SubSub1()]),
"SELECT sub1 AS sub1_1, sub2 AS sub2_1, subsub1 AS subsub1_1",
use_default_dialect=True,
)
@compiles(Sub1)
def visit_sub1(element, compiler, **kw):
return "FOO" + element.name
self.assert_compile(
select([Sub1(), Sub2(), SubSub1()]),
"SELECT FOOsub1 AS sub1_1, sub2 AS sub2_1, "
"FOOsubsub1 AS subsub1_1",
use_default_dialect=True,
)