Return an Alias object.
An Alias represents any FromClause with an alternate name assigned within SQL, typically using the AS clause when generated, e.g. SELECT * FROM table AS aliasname.
Similar functionality is available via the alias() method available on all FromClause subclasses.
- selectable
- any FromClause subclass, such as a table, select statement, etc..
- alias
- string name to be assigned as the alias. If None, a random name will be generated.
Join a list of clauses together using the AND operator.
The & operator is also overloaded on all _CompareMixin subclasses to produce the same result.
Return a BETWEEN predicate clause.
Equivalent of SQL clausetest BETWEEN clauseleft AND clauseright.
The between() method on all _CompareMixin subclasses provides similar functionality.
Create a bind parameter clause with the given key.
Produce a CASE statement.
Return a CAST function.
Equivalent of SQL CAST(clause AS totype).
Use with a TypeEngine subclass, i.e:
cast(table.c.unit_price * table.c.qty, Numeric(10,4))
or:
cast(table.c.timestamp, DATE)
Return a textual column clause, as would be in the columns clause of a SELECT statement.
The object returned is an instance of _ColumnClause, which represents the "syntactical" portion of the schema-level Column object.
Return an EXCEPT of multiple selectables.
The returned object is an instance of CompoundSelect.
Return an EXCEPT ALL of multiple selectables.
The returned object is an instance of CompoundSelect.
Return an Insert clause element.
Similar functionality is available via the insert() method on Table.
If both values and compile-time bind parameters are present, the compile-time bind parameters override the information specified within values on a per-key basis.
The keys within values can be either Column objects or their string identifiers. Each key may reference one of:
If a SELECT statement is specified which references this INSERT statement's table, the statement will be correlated against the INSERT statement.
Return an INTERSECT of multiple selectables.
The returned object is an instance of CompoundSelect.
Return an INTERSECT ALL of multiple selectables.
The returned object is an instance of CompoundSelect.
Return a JOIN clause element (regular inner join).
The returned object is an instance of Join.
Similar functionality is also available via the join() method on any FromClause.
To chain joins together, use the join() or outerjoin() methods on the resulting Join object.
Return a literal clause, bound to a bind parameter.
Literal clauses are created automatically when non- ClauseElement objects (such as strings, ints, dates, etc.) are used in a comparison operation with a _CompareMixin subclass, such as a Column object. Use this function to force the generation of a literal clause, which will be created as a _BindParamClause with a bound value.
Return a textual column clause, as would be in the columns clause of a SELECT statement.
The object returned is an instance of _ColumnClause, which represents the "syntactical" portion of the schema-level Column object.
Return a negation of the given clause, i.e. NOT(clause).
The ~ operator is also overloaded on all _CompareMixin subclasses to produce the same result.
Join a list of clauses together using the OR operator.
The | operator is also overloaded on all _CompareMixin subclasses to produce the same result.
Return an OUTER JOIN clause element.
The returned object is an instance of Join.
Similar functionality is also available via the outerjoin() method on any FromClause.
To chain joins together, use the join() or outerjoin() methods on the resulting Join object.
Create an 'OUT' parameter for usage in functions (stored procedures), for databases which support them.
The outparam can be used like a regular function parameter. The "output" value will be available from the ResultProxy object via its out_parameters attribute, which returns a dictionary containing the values.
Returns a SELECT clause element.
Similar functionality is also available via the select() method on any FromClause.
The returned object is an instance of Select.
All arguments which accept ClauseElement arguments also accept string arguments, which will be converted as appropriate into either text() or literal_column() constructs.
A list of ClauseElement objects, typically ColumnElement objects or subclasses, which will form the columns clause of the resulting statement. For all members which are instances of Selectable, the individual ColumnElement members of the Selectable will be added individually to the columns clause. For example, specifying a Table instance will result in all the contained Column objects within to be added to the columns clause.
This argument is not present on the form of select() available on Table.
Additional parameters include:
Return a Table object.
This is a primitive version of the Table object, which is a subclass of this object.
Create literal text to be inserted into a query.
When constructing a query from a select(), update(), insert() or delete(), using plain strings for argument values will usually result in text objects being created automatically. Use this function when creating textual clauses outside of other ClauseElement objects, or optionally wherever plain text is to be used.
Return a UNION of multiple selectables.
The returned object is an instance of CompoundSelect.
A similar union() method is available on all FromClause subclasses.
Return a UNION ALL of multiple selectables.
The returned object is an instance of CompoundSelect.
A similar union_all() method is available on all FromClause subclasses.
Return an Update clause element.
Similar functionality is available via the update() method on Table.
If both values and compile-time bind parameters are present, the compile-time bind parameters override the information specified within values on a per-key basis.
The keys within values can be either Column objects or their string identifiers. Each key may reference one of:
If a SELECT statement is specified which references this UPDATE statement's table, the statement will be correlated against the UPDATE statement.
Represents an table or selectable alias (AS).
Represents an alias, as typically applied to any table or sub-select within a SQL statement using the AS keyword (or without the keyword on certain databases such as Oracle).
This object is constructed from the alias() module level function as well as the alias() method available on all FromClause subclasses.
Base class for elements of a programmatically constructed SQL expression.
Returns the Engine or Connection to which this ClauseElement is bound, or None if none found.
Compare this ClauseElement to the given ClauseElement.
Subclasses should override the default behavior, which is a straight identity comparison.
Compile this SQL expression.
Uses the given Compiler, or the given AbstractDialect or Engine to create a Compiler. If no compiler arguments are given, tries to use the underlying Engine this ClauseElement is bound to to create a Compiler, if any.
Finally, if there is no bound Engine, uses an DefaultDialect to create a default Compiler.
parameters is a dictionary representing the default bind parameters to be used with the statement. If parameters is a list, it is assumed to be a list of dictionaries and the first dictionary in the list is used with which to compile against.
The bind parameters can in some cases determine the output of the compilation, such as for UPDATE and INSERT statements the bind parameters that are present determine the SET and VALUES clause of those statements.
Return immediate child elements of this ClauseElement.
This is used for visit traversal.
**kwargs may contain flags that change the collection that is returned, for example to return a subset of items in order to cut down on larger traversals, or to return child items from a different context (such as schema-level collections instead of clause-level).
Return a copy with bindparam() elments replaced.
Returns a copy of this ClauseElement with bindparam() elements replaced with values taken from the given dictionary:
>>> clause = column('x') + bindparam('foo') >>> print clause.compile().params {'foo':None} >>> print clause.params({'foo':7}).compile().params {'foo':7}
Compile and execute this ClauseElement, returning the result's scalar representation.
Return True if this clause element represents a complete executable statement.
Return a copy with bindparam() elments replaced.
Same functionality as params(), except adds unique=True to affected bind parameters so that multiple statements can be used.
A class that knows how to traverse and visit ClauseElements.
Calls visit_XXX() methods dynamically generated for each particualr ClauseElement subclass encountered. Traversal of a hierarchy of ClauseElements is achieved via the traverse() method, which is passed the lead ClauseElement.
By default, ClauseVisitor traverses all elements fully. Options can be specified at the class level via the __traverse_options__ dictionary which will be passed to the get_children() method of each ClauseElement; these options can indicate modifications to the set of elements returned, such as to not return column collections (column_collections=False) or to return Schema-level items (schema_visitor=True).
ClauseVisitor also supports a simultaneous copy-and-traverse operation, which will produce a copy of a given ClauseElement structure while at the same time allowing ClauseVisitor subclasses to modify the new structure in-place.
'chain' an additional ClauseVisitor onto this ClauseVisitor.
the chained visitor will receive all visit events after this one.
An ordered dictionary that stores a list of ColumnElement instances.
Overrides the __eq__() method to produce SQL clauses between sets of correlated columns.
Add a column to this collection.
The key attribute of the column will be used as the hash key for this dictionary.
Represent an element that is usable within the "column clause" portion of a SELECT statement.
This includes columns associated with tables, aliases, and subqueries, expressions, function calls, SQL keywords such as NULL, literals, etc. ColumnElement is the ultimate base class for all such elements.
ColumnElement supports the ability to be a proxy element, which indicates that the ColumnElement may be associated with a Selectable which was derived from another Selectable. An example of a "derived" Selectable is an Alias of a Table.
A ColumnElement, by subclassing the _CompareMixin mixin class, provides the ability to generate new ClauseElement objects using Python expressions. See the _CompareMixin docstring for more details.
Foreign key accessor. References a list of ForeignKey objects which each represent a foreign key placed on this column's ultimate ancestor.
A Set containing TableClause-bound, non-proxied ColumnElements for which this ColumnElement is a proxy. In all cases except for a column proxied from a Union (i.e. CompoundSelect), this set will be just one element.
Primary key flag. Indicates if this Column represents part or whole of a primary key for its parent table.
Return True if the given ColumnElement has a common ancestor to this ColumnElement.
Represent an element that can be used within the FROM clause of a SELECT statement.
Given a ColumnElement, return the exported ColumnElement object from this Selectable which corresponds to that original Column via a common anscestor column.
Return True if this FromClause is 'derived' from the given FromClause.
An example would be an Alias of a Table is derived from that Table.
True if the name of this FromClause may be prepended to a column in a generated SQL statement.
A dictionary mapping an original Table-bound column to a proxied column in this FromClause.
replace all occurences of FromClause 'old' with the given Alias object, returning a copy of this FromClause.
represent a JOIN construct between two FromClause elements.
The public constructor function for Join is the module-level join() function, as well as the join() method available off all FromClause subclasses.
Create a Select out of this Join clause and return an Alias of it.
The Select is not correlating.
Returns the column list of this Join with all equivalently-named, equated columns folded into one column, where 'equated' means they are equated to each other in the ON clause of this join.
Create a Select from this Join.
a ClauseVisitor that will not traverse the exported Column collections on Table, Alias, Select, and CompoundSelect objects (i.e. their 'columns' or 'c' attribute).
this is useful because most traversals don't need those columns, or in the case of DefaultCompiler it traverses them explicitly; so skipping their traversal here greatly cuts down on method call overhead.
Represents a SELECT statement.
Select statements support appendable clauses, as well as the ability to execute themselves and return a result set.
Construct a Select object.
The public constructor for Select is the select() function; see that function for argument descriptions.
append the given column expression to the columns clause of this select() construct.
append the given correlation expression to this select() construct.
append the given expression to this select() construct's HAVING criterion.
The expression will be joined to existing HAVING criterion via AND.
append the given columns clause prefix expression to this select() construct.
append the given expression to this select() construct's WHERE criterion.
The expression will be joined to existing WHERE criterion via AND.
return a new select() construct with the given column expression added to its columns clause.
return a new select() construct which will correlate the given FROM clause to that of an enclosing select(), if a match is found.
By "match", the given fromclause must be present in this select's list of FROM objects and also present in an enclosing select's list of FROM objects.
Calling this method turns off the select's default behavior of "auto-correlation". Normally, select() auto-correlates all of its FROM clauses to those of an embedded select when compiled.
If the fromclause is None, the select() will not correlate to anything.
Return a list of all FromClause elements which will be applied to the FROM clause of the resulting statement.
return a new select() construct with the given expression added to its HAVING clause, joined to the existing clause via AND, if any.
return a new select() construct which will apply the given expression to the start of its columns clause, not using any commas.
return a new select() construct with the given FROM expression applied to its list of FROM objects.
return a new select() construct with the given expression added to its WHERE clause, joined to the existing clause via AND, if any.
Represent a column list-holding object.
This is the common base class of ColumnElement and FromClause. The reason ColumnElement is marked as a "list-holding" object is so that it can be treated similarly to FromClause in column-selection scenarios; it contains a list of columns consisting of itself.
a ColumnCollection containing ColumnElement instances.
Represents a "table" construct.
Note that this represents tables only as another syntactical construct within SQL expressions; it does not provide schema-level functionality.