A list of instances used to provide information about parameters embedded in the statement. An alternative to is the function. The class can also be used directly when programmatically constructing expressions. For literal string values, the flag may be set to True to apply escaping to occurences of these characters within the string value so that they match as themselves and not as wildcard characters. This is used for visit traversal.
The object also can return a dictionary of bind parameter names and values using the params accessor. A value of 100 will be higher or equal to all operators, and -100 will be lower than or equal to all operators. In a column context, produces the clause a! If either of these parameters are present, then defaults to False. If you need info for debugging, let me know. In a column context, produces the clause a! The key attribute of the column will be used as the hash key for this dictionary. If None, all columns from the target table object are rendered. It returns an instance of.
By re-using a , we save on the Python work within the session. This may apply to an array type for some dialects e. The type of a is significant especially in that the type will apply pre-processing to the value before it is passed to the database. Thanks again for all your hard work on this library. Subclasses should override the default behavior, which is a straight identity comparison. If left as None the type will be NullType.
The dialect must also include an existing collection, indicating that it participates in the keyword-argument validation and default system, else is raised. A type that features bound-value handling will also have that behavior take effect when literal values or constructs are passed to as targets. Otherwise, it overrides the normal algorithm and the outcome is cached. The object is where the actual object gets created, or retrieved from the cache, against a target , and is then invoked for results. The ~ operator is also overloaded on all subclasses to produce the same result. However I only noticed today that the value gets cached. We can build a statement without the need to refer to any pre-established Table metadata.
Whenever I try to pass an array index, it gets turned into a bound param causing an error unless I wrap the integer in db. The object is normally created automatically when specifying the name for key schema constructs such as , , and others. The outparam can be used like a regular function parameter. The dialect must be locatable, else a is raised. This method adds additional criteria to the initial criteria set up by.
To specify a column-name expression which should be subject to quoting rules, use the function. Calling str or unicode on the returned value will yield a string representation of the result. This is a label expression which will be named at compile time. The ~ operator is also overloaded on all subclasses to produce the same result. In a column context, produces the clause -a. It is critical to keep in mind that the baked query feature only applies to building the query itself, not the fetching of results. This is the lowest level of operation, raises NotImplementedError by default.
This function has the same signature as that of. This allows any custom flag to be passed through to a custom compilation construct, for example. Such as to use the method with an unconditionally quoted name: New in version 0. See also - flat dictionary form kwargs A synonym for. Otherwise, it overrides the normal algorithm and the outcome is cached. Now we have one Person object and one Address object stored in the database.
This dictionary provides a list of argument names accepted by various schema-level constructs on behalf of a dialect. A value of 100 will be higher or equal to all operators, and -100 will be lower than or equal to all operators. Overriding this on a subclass can allow common behavior to be applied to all operations. A unary expression has a single column expression and an operator. Implements base methods and , as well as , ,. This parameter now invokes the method, which returns a construct that gains a.
Apologies in advance if I'm missing something really obvious here. The use case for ad-hoc addition of argument names is typically for end-user code that is also using a custom compilation scheme which consumes the additional arguments. The object also can return a dictionary of bind parameter names and values using the params accessor. Calling str or unicode on the returned value will yield a string representation of the result. This is used to expand the comparison to other columns that may be known to be equivalent to this one via foreign key or other criterion.
This typically refers to Sequence execution but may also refer to any server-side default generation function associated with a primary key Column. Alternatively, the parameter will establish a given character as an escape character which can be of use when the target expression is not a literal string. The type of a is significant especially in that the type will apply pre-processing to the value before it is passed to the database. Constructing two users with the same address and using session. The base method of just returns self. If None, all columns from the target table object are rendered. Usage is the same as operate.