org.apache.calcite.schema

Class Schemas

java.lang.Object

org.apache.calcite.schema.Schemas

public final class Schemas
extends Object

Utility functions for schemas.

Method Summary

Methods

Modifier and Type	Method and Description
static CalcitePrepare.ConvertResult	convert(CalciteConnection connection, CalciteSchema schema, List<String> schemaPath, String sql) Parses and validates a SQL query and converts to relational algebra.
static DataContext	createDataContext(Connection connection)
static Enumerable<Object[]>	enumerable(FilterableTable table, DataContext root) Returns an Enumerable over the rows of a given table, not applying any filters, representing each row as an object array.
static Enumerable<Object[]>	enumerable(ProjectableFilterableTable table, DataContext root) Returns an Enumerable over the rows of a given table, not applying any filters and projecting all columns, representing each row as an object array.
static Enumerable<Object[]>	enumerable(ScannableTable table, DataContext root) Returns an Enumerable over the rows of a given table, representing each row as an object array.
static Expression	expression(SchemaPlus schema) Returns the expression for a schema.
static List<CalciteSchema.LatticeEntry>	getLatticeEntries(CalciteSchema schema) Returns the lattices defined in a schema.
static List<Lattice>	getLattices(CalciteSchema schema) Returns the lattices defined in a schema.
static List<CalciteSchema.TableEntry>	getStarTables(CalciteSchema schema) Returns the star tables defined in a schema.
static CalcitePrepare.Context	makeContext(CalciteConnection connection, CalciteSchema schema, List<String> schemaPath, com.google.common.collect.ImmutableMap<CalciteConnectionProperty,String> propValues)
static CalcitePrepare.ParseResult	parse(CalciteConnection connection, CalciteSchema schema, List<String> schemaPath, String sql) Parses and validates a SQL query.
static CalcitePrepare.CalciteSignature<Object>	prepare(CalciteConnection connection, CalciteSchema schema, List<String> schemaPath, String sql, com.google.common.collect.ImmutableMap<CalciteConnectionProperty,String> map) Prepares a SQL query for execution.
static RelProtoDataType	proto(ScalarFunction function) Returns an implementation of RelProtoDataType that asks a given scalar function for its return type with a given type factory.
static RelProtoDataType	proto(Table table) Returns an implementation of RelProtoDataType that asks a given table for its row type with a given type factory.
static <E> Queryable<E>	queryable(DataContext root, Class<E> clazz, Iterable<? extends String> names) Returns a Queryable, given a fully-qualified table name as an iterable.
static <E> Queryable<E>	queryable(DataContext root, Class<E> clazz, String... names) Returns a Queryable, given a fully-qualified table name.
static <E> Queryable<E>	queryable(DataContext root, SchemaPlus schema, Class<E> clazz, String tableName) Returns a Queryable, given a schema and table name.
static CalciteSchema.FunctionEntry	resolve(RelDataTypeFactory typeFactory, String name, Collection<CalciteSchema.FunctionEntry> functionEntries, List<RelDataType> argumentTypes)
static CalciteSchema	subSchema(CalciteSchema schema, List<String> names)
static Expression	subSchemaExpression(SchemaPlus schema, String name, Class type) Returns the expression for a sub-schema.
static Table	table(DataContext root, String... names) Returns an Enumerable over object arrays, given a fully-qualified table name which leads to a ScannableTable.
static Expression	tableExpression(SchemaPlus schema, Type elementType, String tableName, Class clazz) Returns the expression to access a table within a schema.
static String	uniqueTableName(CalciteSchema schema, String base) Generates a table name that is unique within the given schema.
static Expression	unwrap(Expression call, Class type) Converts a schema expression to a given type by calling the SchemaPlus.unwrap(Class) method.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

resolve

public static CalciteSchema.FunctionEntry resolve(RelDataTypeFactory typeFactory,
                                  String name,
                                  Collection<CalciteSchema.FunctionEntry> functionEntries,
                                  List<RelDataType> argumentTypes)

expression

public static Expression expression(SchemaPlus schema)

Returns the expression for a schema.

subSchemaExpression

public static Expression subSchemaExpression(SchemaPlus schema,
                             String name,
                             Class type)

Returns the expression for a sub-schema.

unwrap

public static Expression unwrap(Expression call,
                Class type)

Converts a schema expression to a given type by calling the SchemaPlus.unwrap(Class) method.

tableExpression

public static Expression tableExpression(SchemaPlus schema,
                         Type elementType,
                         String tableName,
                         Class clazz)

Returns the expression to access a table within a schema.

createDataContext

public static DataContext createDataContext(Connection connection)

queryable

public static <E> Queryable<E> queryable(DataContext root,
                         Class<E> clazz,
                         String... names)

Returns a Queryable, given a fully-qualified table name.

queryable

public static <E> Queryable<E> queryable(DataContext root,
                         Class<E> clazz,
                         Iterable<? extends String> names)

Returns a Queryable, given a fully-qualified table name as an iterable.

queryable

public static <E> Queryable<E> queryable(DataContext root,
                         SchemaPlus schema,
                         Class<E> clazz,
                         String tableName)

Returns a Queryable, given a schema and table name.

enumerable

public static Enumerable<Object[]> enumerable(ScannableTable table,
                              DataContext root)

Returns an Enumerable over the rows of a given table, representing each row as an object array.

enumerable

public static Enumerable<Object[]> enumerable(FilterableTable table,
                              DataContext root)

Returns an Enumerable over the rows of a given table, not applying any filters, representing each row as an object array.

enumerable

public static Enumerable<Object[]> enumerable(ProjectableFilterableTable table,
                              DataContext root)

Returns an Enumerable over the rows of a given table, not applying any filters and projecting all columns, representing each row as an object array.

table

public static Table table(DataContext root,
          String... names)

Returns an Enumerable over object arrays, given a fully-qualified table name which leads to a ScannableTable.

parse

public static CalcitePrepare.ParseResult parse(CalciteConnection connection,
                               CalciteSchema schema,
                               List<String> schemaPath,
                               String sql)

Parses and validates a SQL query. For use within Calcite only.

convert

public static CalcitePrepare.ConvertResult convert(CalciteConnection connection,
                                   CalciteSchema schema,
                                   List<String> schemaPath,
                                   String sql)

Parses and validates a SQL query and converts to relational algebra. For use within Calcite only.

prepare

public static CalcitePrepare.CalciteSignature<Object> prepare(CalciteConnection connection,
                                              CalciteSchema schema,
                                              List<String> schemaPath,
                                              String sql,
                                              com.google.common.collect.ImmutableMap<CalciteConnectionProperty,String> map)

Prepares a SQL query for execution. For use within Calcite only.

makeContext

public static CalcitePrepare.Context makeContext(CalciteConnection connection,
                                 CalciteSchema schema,
                                 List<String> schemaPath,
                                 com.google.common.collect.ImmutableMap<CalciteConnectionProperty,String> propValues)

proto

public static RelProtoDataType proto(Table table)

Returns an implementation of RelProtoDataType that asks a given table for its row type with a given type factory.

proto

public static RelProtoDataType proto(ScalarFunction function)

Returns an implementation of RelProtoDataType that asks a given scalar function for its return type with a given type factory.

getStarTables

public static List<CalciteSchema.TableEntry> getStarTables(CalciteSchema schema)

Returns the star tables defined in a schema.

Parameters:

schema - Schema

getLattices

public static List<Lattice> getLattices(CalciteSchema schema)

Returns the lattices defined in a schema.

Parameters:

schema - Schema

getLatticeEntries

public static List<CalciteSchema.LatticeEntry> getLatticeEntries(CalciteSchema schema)

Returns the lattices defined in a schema.

Parameters:

schema - Schema

subSchema

public static CalciteSchema subSchema(CalciteSchema schema,
                      List<String> names)

uniqueTableName

public static String uniqueTableName(CalciteSchema schema,
                     String base)

Generates a table name that is unique within the given schema.