org.apache.calcite.adapter.jdbc

Class JdbcSchema

java.lang.Object

org.apache.calcite.adapter.jdbc.JdbcSchema

All Implemented Interfaces:

Schema

public class JdbcSchema
extends Object
implements Schema

Implementation of Schema that is backed by a JDBC data source.

The tables in the JDBC data source appear to be tables in this schema; queries against this schema are executed against those tables, pushing down as much as possible of the query logic to SQL.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	JdbcSchema.Factory Schema factory that creates a JdbcSchema.

Nested classes/interfaces inherited from interface org.apache.calcite.schema.Schema

Schema.TableType

Field Summary

Fields

Modifier and Type	Field and Description
SqlDialect	dialect

Constructor Summary

Constructors

Constructor and Description
JdbcSchema(DataSource dataSource, SqlDialect dialect, JdbcConvention convention, String catalog, String schema) Creates a JDBC schema.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	contentsHaveChangedSince(long lastCheck, long now) Returns whether the contents of this schema have changed since a given time.
static JdbcSchema	create(SchemaPlus parentSchema, String name, DataSource dataSource, String catalog, String schema)
static JdbcSchema	create(SchemaPlus parentSchema, String name, Map<String,Object> operand) Creates a JdbcSchema, taking credentials from a map.
static SqlDialect	createDialect(DataSource dataSource) Returns a suitable SQL dialect for the given data source.
static DataSource	dataSource(String url, String driverClassName, String username, String password) Creates a JDBC data source with the given specification.
DataSource	getDataSource()
Expression	getExpression(SchemaPlus parentSchema, String name) Returns the expression by which this schema can be referenced in generated code.
Set<String>	getFunctionNames() Returns the names of the functions in this schema.
protected com.google.common.collect.Multimap<String,Function>	getFunctions()
Collection<Function>	getFunctions(String name) Returns a list of functions in this schema with the given name, or an empty list if there is no such function.
Schema	getSubSchema(String name) Returns a sub-schema with a given name, or null.
Set<String>	getSubSchemaNames() Returns the names of this schema's child schemas.
Table	getTable(String name) Returns a table with a given name, or null if not found.
Set<String>	getTableNames() Returns the names of the tables in this schema.
boolean	isMutable() Returns whether the user is allowed to create new tables, functions and sub-schemas in this schema, in addition to those returned automatically by methods such as Schema.getTable(String).

Methods inherited from class java.lang.Object

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

Field Detail

dialect

public final SqlDialect dialect

Constructor Detail

JdbcSchema

public JdbcSchema(DataSource dataSource,
          SqlDialect dialect,
          JdbcConvention convention,
          String catalog,
          String schema)

Creates a JDBC schema.

Parameters:

dataSource - Data source

dialect - SQL dialect

convention - Calling convention

catalog - Catalog name, or null

schema - Schema name pattern

Method Detail

create

public static JdbcSchema create(SchemaPlus parentSchema,
                String name,
                DataSource dataSource,
                String catalog,
                String schema)

create

public static JdbcSchema create(SchemaPlus parentSchema,
                String name,
                Map<String,Object> operand)

Creates a JdbcSchema, taking credentials from a map.

Parameters:

parentSchema - Parent schema

name - Name

operand - Map of property/value pairs

Returns:

A JdbcSchema

createDialect

public static SqlDialect createDialect(DataSource dataSource)

Returns a suitable SQL dialect for the given data source.

dataSource

public static DataSource dataSource(String url,
                    String driverClassName,
                    String username,
                    String password)

Creates a JDBC data source with the given specification.

isMutable

public boolean isMutable()

Description copied from interface: Schema

Returns whether the user is allowed to create new tables, functions and sub-schemas in this schema, in addition to those returned automatically by methods such as Schema.getTable(String).

Even if this method returns true, the maps are not modified. Calcite stores the defined objects in a wrapper object.

Specified by:

isMutable in interface Schema

Returns:

Whether the user is allowed to create new tables, functions and sub-schemas in this schema

contentsHaveChangedSince

public boolean contentsHaveChangedSince(long lastCheck,
                               long now)

Description copied from interface: Schema

Returns whether the contents of this schema have changed since a given time. The time is a millisecond value, as returned by System.currentTimeMillis(). If this method returns true, and caching is enabled, Calcite will re-build caches.

The default implementation in AbstractSchema always returns false.

To control whether Calcite caches the contents of a schema, use the "cache" JSON attribute. The default value is "true".

Specified by:

contentsHaveChangedSince in interface Schema

Parameters:

lastCheck - The last time that Calcite called this method, or Long.MIN_VALUE if this is the first call

now - The current time in millis, as returned by System.currentTimeMillis()

Returns:

Whether contents changed after lastCheckMillis.

getDataSource

public DataSource getDataSource()

getExpression

public Expression getExpression(SchemaPlus parentSchema,
                       String name)

Description copied from interface: Schema

Returns the expression by which this schema can be referenced in generated code.

Specified by:

getExpression in interface Schema

Parameters:

parentSchema - Parent schema

name - Name of this schema

Returns:

Expression by which this schema can be referenced in generated code

getFunctions

protected com.google.common.collect.Multimap<String,Function> getFunctions()

getFunctions

public final Collection<Function> getFunctions(String name)

Description copied from interface: Schema

Returns a list of functions in this schema with the given name, or an empty list if there is no such function.

Specified by:

getFunctions in interface Schema

Parameters:

name - Name of function

Returns:

List of functions with given name, or empty list

getFunctionNames

public final Set<String> getFunctionNames()

Description copied from interface: Schema

Returns the names of the functions in this schema.

Specified by:

getFunctionNames in interface Schema

Returns:

Names of the functions in this schema

getTable

public Table getTable(String name)

Description copied from interface: Schema

Returns a table with a given name, or null if not found.

Specified by:

getTable in interface Schema

Parameters:

name - Table name

Returns:

Table, or null

getTableNames

public Set<String> getTableNames()

Description copied from interface: Schema

Returns the names of the tables in this schema.

Specified by:

getTableNames in interface Schema

Returns:

Names of the tables in this schema

getSubSchema

public Schema getSubSchema(String name)

Description copied from interface: Schema

Returns a sub-schema with a given name, or null.

Specified by:

getSubSchema in interface Schema

Parameters:

name - Sub-schema name

Returns:

Sub-schema with a given name, or null

getSubSchemaNames

public Set<String> getSubSchemaNames()

Description copied from interface: Schema

Returns the names of this schema's child schemas.

Specified by:

getSubSchemaNames in interface Schema

Returns:

Names of this schema's child schemas