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

Modifier and Type	Method and Description
static CalcitePrepare.AnalyzeViewResult	analyzeView(CalciteConnection connection, CalciteSchema schema, @Nullable List<String> schemaPath, String viewSql, @Nullable List<String> viewPath, boolean fail) Analyzes a view.
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, @Nullable SchemaPlus rootSchema)
static org.apache.calcite.linq4j.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 org.apache.calcite.linq4j.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 org.apache.calcite.linq4j.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 org.apache.calcite.linq4j.tree.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 org.apache.calcite.linq4j.tree.Expression	getTableExpression(SchemaPlus schema, String tableName, Table table, Class<?> clazz) Generates an expression with which table can be referenced in generated code.
static CalcitePrepare.ParseResult	parse(CalciteConnection connection, CalciteSchema schema, @Nullable List<String> schemaPath, String sql) Parses and validates a SQL query.
static Path	path(CalciteSchema rootSchema, Iterable<String> names) Creates a path with a given list of names starting from a given root schema.
static org.apache.calcite.schema.Schemas.PathImpl	path(com.google.common.collect.ImmutableList<Pair<String,Schema>> build)
static Path	path(SchemaPlus schema) Returns the path to get to a schema from its root.
static CalcitePrepare.CalciteSignature<Object>	prepare(CalciteConnection connection, CalciteSchema schema, @Nullable 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> org.apache.calcite.linq4j.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> org.apache.calcite.linq4j.Queryable<E>	queryable(DataContext root, Class<E> clazz, String... names) Returns a Queryable, given a fully-qualified table name.
static <E> org.apache.calcite.linq4j.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 @Nullable CalciteSchema	subSchema(CalciteSchema schema, Iterable<String> names) Returns a sub-schema of a given schema obtained by following a sequence of names.
static org.apache.calcite.linq4j.tree.Expression	subSchemaExpression(SchemaPlus schema, String name, Class type) Returns the expression for a sub-schema.
static @Nullable Table	table(DataContext root, String... names) Returns an Enumerable over object arrays, given a fully-qualified table name which leads to a ScannableTable.
static org.apache.calcite.linq4j.tree.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 org.apache.calcite.linq4j.tree.Expression	unwrap(org.apache.calcite.linq4j.tree.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 org.apache.calcite.linq4j.tree.Expression expression(SchemaPlus schema)

Returns the expression for a schema.

subSchemaExpression

public static org.apache.calcite.linq4j.tree.Expression subSchemaExpression(SchemaPlus schema,
                                                                            String name,
                                                                            Class type)

Returns the expression for a sub-schema.

unwrap

public static org.apache.calcite.linq4j.tree.Expression unwrap(org.apache.calcite.linq4j.tree.Expression call,
                                                               Class type)

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

tableExpression

public static org.apache.calcite.linq4j.tree.Expression tableExpression(SchemaPlus schema,
                                                                        Type elementType,
                                                                        String tableName,
                                                                        Class clazz)

Returns the expression to access a table within a schema.

getTableExpression

public static org.apache.calcite.linq4j.tree.Expression getTableExpression(SchemaPlus schema,
                                                                           String tableName,
                                                                           Table table,
                                                                           Class<?> clazz)

Generates an expression with which table can be referenced in generated code.

Parameters:

schema - Schema

tableName - Table name (unique within schema)

table - Table to be referenced

clazz - Class that provides specific methods for accessing table data. It may differ from the table class; for example clazz may be MongoTable.MongoQueryable, though table is MongoTable

createDataContext

public static DataContext createDataContext(Connection connection,
                                            @Nullable SchemaPlus rootSchema)

queryable

public static <E> org.apache.calcite.linq4j.Queryable<E> queryable(DataContext root,
                                                                   Class<E> clazz,
                                                                   String... names)

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

queryable

public static <E> org.apache.calcite.linq4j.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> org.apache.calcite.linq4j.Queryable<E> queryable(DataContext root,
                                                                   SchemaPlus schema,
                                                                   Class<E> clazz,
                                                                   String tableName)

Returns a Queryable, given a schema and table name.

enumerable

public static org.apache.calcite.linq4j.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 org.apache.calcite.linq4j.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 org.apache.calcite.linq4j.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 @Nullable 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,
                                               @Nullable 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.

analyzeView

public static CalcitePrepare.AnalyzeViewResult analyzeView(CalciteConnection connection,
                                                           CalciteSchema schema,
                                                           @Nullable List<String> schemaPath,
                                                           String viewSql,
                                                           @Nullable List<String> viewPath,
                                                           boolean fail)

Analyzes a view. For use within Calcite only.

prepare

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

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

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 @Nullable CalciteSchema subSchema(CalciteSchema schema,
                                                Iterable<String> names)

Returns a sub-schema of a given schema obtained by following a sequence of names.

The result is null if the initial schema is null or any sub-schema does not exist.

uniqueTableName

public static String uniqueTableName(CalciteSchema schema,
                                     String base)

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

path

public static Path path(CalciteSchema rootSchema,
                        Iterable<String> names)

Creates a path with a given list of names starting from a given root schema.

path

public static org.apache.calcite.schema.Schemas.PathImpl path(com.google.common.collect.ImmutableList<Pair<String,Schema>> build)

path

public static Path path(SchemaPlus schema)

Returns the path to get to a schema from its root.