Package 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	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 Enumerable<@Nullable 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<@Nullable 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<@Nullable 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 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(Iterable<? extends Map.Entry<String,Schema>> list)
static Path	path(CalciteSchema rootSchema, Iterable<String> names)	Creates a path with a given list of names starting from a given root schema.
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> 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 @Nullable 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 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 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 Details

resolve

public static @Nullable 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.

getTableExpression

public static 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> 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<@Nullable 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<@Nullable 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<@Nullable 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 Path path(Iterable<? extends Map.Entry<String,Schema>> list)

path

public static Path path(SchemaPlus schema)

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