gavo.adql.common module

Exceptions and helper functions for ADQL processing.

class gavo.adql.common.Absent

Bases: object

is a sentinel to pass as default to nodes.getChildOfType.

exception gavo.adql.common.AmbiguousColumn(msg='', hint=None)

Bases: gavo.adql.common.Error

is raised if a column name matches more than one column in a compound query.

exception gavo.adql.common.BadKeywords(msg='', hint=None)

Bases: gavo.adql.common.Error

is raised when an ADQL node is constructed with bad keywords.

This is a development help and should not occur in production code.

exception gavo.adql.common.ColumnNotFound(colName, hint=None)

Bases: gavo.adql.common.Error, gavo.utils.excs.NotFoundError

is raised if a column name cannot be resolved.

exception gavo.adql.common.Error(msg='', hint=None)

Bases: gavo.utils.excs.Error

A base class for the exceptions from this module.

class gavo.adql.common.FieldInfoGetter

Bases: object

An abstract class to retrieve table metadata.

A subclass of this must be passed into adql.parseAnnotating. Implementations must fill out the getInfosFor(tableName) method, which must return a sequence of (column name, adql.FieldInfo) pairs for the named table.

plain strings for table names will be normalised (lowercased).

addExtraFieldInfos(tableName, fieldInfos)

adds field infos for tableName.

fieldInfos must be a sequence of (columnName, adql.FieldInfo) pairs.

Note that tableName is normalised to lowercase here.

getInfosFor(tableName)

normalizeName(tableName)

exception gavo.adql.common.FlattenError(msg='', hint=None)

Bases: gavo.adql.common.Error

is raised when something cannot be flattened.

exception gavo.adql.common.GeometryError(msg='', hint=None)

Bases: gavo.adql.common.Error

is raised if something is wrong with a geometry.

exception gavo.adql.common.IncompatibleTables(msg='', hint=None)

Bases: gavo.adql.common.Error

is raised when the operands of a set operation are not deemed compatible.

exception gavo.adql.common.MoreThanOneChild(searchedType, toks)

Bases: gavo.adql.common.NoChild

is raised if a node is asked for a unique child but has more than one.

exception gavo.adql.common.MorphError(msg='', hint=None)

Bases: gavo.adql.common.Error

is raised when the expectations of the to-ADQL morphers are violated.

exception gavo.adql.common.NoChild(searchedType, toks)

Bases: gavo.adql.common.Error

is raised if a node is asked for a non-existing child.

exception gavo.adql.common.NotImplementedError(msg='', hint=None)

Bases: gavo.adql.common.Error

is raised for features we don’t (yet) support.

exception gavo.adql.common.RegionError(msg='', hint=None)

Bases: gavo.adql.common.GeometryError

is raised if a region specification is in some way bad.

exception gavo.adql.common.TableNotFound(tableName, hint=None)

Bases: gavo.adql.common.Error, gavo.utils.excs.NotFoundError

is raised when a table name cannot be resolved.

exception gavo.adql.common.UfuncError(msg='', hint=None)

Bases: gavo.adql.common.Error

is raised if something is wrong with a call to a user defined function.

gavo.adql.common.computeCommonColumns(tableNode)

returns a set of column names that only occur once in the result table.

For a natural join, that’s all column names occurring in all tables, for a USING join, that’s all names occurring in USING, else it’s an empty set.

gavo.adql.common.getUniqueMatch(matches, colName)

returns the only item of matches if there is exactly one, raises an appropriate exception if not.