@PublicEvolving public interface TableEnvironment
It is unified both on a language level for all JVM-based languages (i.e. there is no distinction between Scala and Java API) and for bounded and unbounded data processing.
A table environment is responsible for:
Table
s and other meta objects from a catalog.
The syntax for path in methods such as createTemporaryView(String, Table)
is following
[[catalog-name.]database-name.]object-name, where the catalog name and database are optional. For
path resolution see useCatalog(String)
and useDatabase(String)
.
Example: `cat.1`.`db`.`Table` resolves to an object named 'Table' in a catalog named 'cat.1' and database named 'db'.
Note: This environment is meant for pure table programs. If you would like to convert from or to other Flink APIs, it might be necessary to use one of the available language-specific table environments in the corresponding bridging modules.
Modifier and Type | Method and Description |
---|---|
ConnectTableDescriptor |
connect(ConnectorDescriptor connectorDescriptor)
Deprecated.
The SQL
CREATE TABLE DDL is richer than this part of the API. This method
might be refactored in the next versions. Please use executeSql(ddl) to register a table instead. |
static TableEnvironment |
create(EnvironmentSettings settings)
Creates a table environment that is the entry point and central context for creating Table
and SQL API programs.
|
void |
createFunction(String path,
Class<? extends UserDefinedFunction> functionClass)
Registers a
UserDefinedFunction class as a catalog function in the given path. |
void |
createFunction(String path,
Class<? extends UserDefinedFunction> functionClass,
boolean ignoreIfExists)
Registers a
UserDefinedFunction class as a catalog function in the given path. |
StatementSet |
createStatementSet()
Create a
StatementSet instance which accepts DML statements or Tables, the planner
can optimize all added statements and Tables together and then submit as one job. |
void |
createTemporaryFunction(String path,
Class<? extends UserDefinedFunction> functionClass)
Registers a
UserDefinedFunction class as a temporary catalog function. |
void |
createTemporaryFunction(String path,
UserDefinedFunction functionInstance)
Registers a
UserDefinedFunction instance as a temporary catalog function. |
void |
createTemporarySystemFunction(String name,
Class<? extends UserDefinedFunction> functionClass)
Registers a
UserDefinedFunction class as a temporary system function. |
void |
createTemporarySystemFunction(String name,
UserDefinedFunction functionInstance)
Registers a
UserDefinedFunction instance as a temporary system function. |
void |
createTemporaryView(String path,
Table view)
Registers a
Table API object as a temporary view similar to SQL temporary views. |
boolean |
dropFunction(String path)
Drops a catalog function registered in the given path.
|
boolean |
dropTemporaryFunction(String path)
Drops a temporary catalog function registered in the given path.
|
boolean |
dropTemporarySystemFunction(String name)
Drops a temporary system function registered under the given name.
|
boolean |
dropTemporaryTable(String path)
Drops a temporary table registered in the given path.
|
boolean |
dropTemporaryView(String path)
Drops a temporary view registered in the given path.
|
JobExecutionResult |
execute(String jobName)
Deprecated.
use
executeSql(String) or Table.executeInsert(String) for single
sink, use createStatementSet() for multiple sinks. |
TableResult |
executeSql(String statement)
Execute the given single statement, and return the execution result.
|
String |
explain(boolean extended)
Deprecated.
|
String |
explain(Table table)
Deprecated.
|
String |
explain(Table table,
boolean extended)
Deprecated.
|
String |
explainSql(String statement,
ExplainDetail... extraDetails)
Returns the AST of the specified statement and the execution plan to compute the result of
the given statement.
|
Table |
from(String path)
Reads a registered table and returns the resulting
Table . |
Table |
fromTableSource(TableSource<?> source)
Deprecated.
|
Table |
fromValues(AbstractDataType<?> rowType,
Expression... values)
Creates a Table from given collection of objects with a given row type.
|
Table |
fromValues(AbstractDataType<?> rowType,
Iterable<?> values)
Creates a Table from given collection of objects with a given row type.
|
default Table |
fromValues(AbstractDataType<?> rowType,
Object... values)
Creates a Table from given collection of objects with a given row type.
|
Table |
fromValues(Expression... values)
Creates a Table from given values.
|
Table |
fromValues(Iterable<?> values)
Creates a Table from given collection of objects.
|
default Table |
fromValues(Object... values)
Creates a Table from given values.
|
Optional<Catalog> |
getCatalog(String catalogName)
Gets a registered
Catalog by name. |
String[] |
getCompletionHints(String statement,
int position)
Deprecated.
Will be removed in the next release
|
TableConfig |
getConfig()
Returns the table config that defines the runtime behavior of the Table API.
|
String |
getCurrentCatalog()
Gets the current default catalog name of the current session.
|
String |
getCurrentDatabase()
Gets the current default database name of the running session.
|
void |
insertInto(String targetPath,
Table table)
Deprecated.
use
Table.executeInsert(String) for single sink, use createStatementSet() for multiple sinks. |
void |
insertInto(Table table,
String sinkPath,
String... sinkPathContinued)
Deprecated.
use
Table.executeInsert(String) for single sink, use createStatementSet() for multiple sinks. |
String[] |
listCatalogs()
Gets the names of all catalogs registered in this environment.
|
String[] |
listDatabases()
Gets the names of all databases registered in the current catalog.
|
String[] |
listFunctions()
Gets the names of all functions in this environment.
|
String[] |
listModules()
Gets an array of names of all modules in this environment in the loaded order.
|
String[] |
listTables()
Gets the names of all tables available in the current namespace (the current database of the
current catalog).
|
String[] |
listTemporaryTables()
Gets the names of all temporary tables and views available in the current namespace (the
current database of the current catalog).
|
String[] |
listTemporaryViews()
Gets the names of all temporary views available in the current namespace (the current
database of the current catalog).
|
String[] |
listUserDefinedFunctions()
Gets the names of all user defined functions registered in this environment.
|
String[] |
listViews()
Gets the names of all views available in the current namespace (the current database of the
current catalog).
|
void |
loadModule(String moduleName,
Module module)
Loads a
Module under a unique name. |
void |
registerCatalog(String catalogName,
Catalog catalog)
Registers a
Catalog under a unique name. |
void |
registerFunction(String name,
ScalarFunction function)
Deprecated.
Use
createTemporarySystemFunction(String, UserDefinedFunction) instead.
Please note that the new method also uses the new type system and reflective extraction
logic. It might be necessary to update the function implementation as well. See the
documentation of ScalarFunction for more information on the new function design. |
void |
registerTable(String name,
Table table)
Deprecated.
|
void |
registerTableSink(String name,
String[] fieldNames,
TypeInformation<?>[] fieldTypes,
TableSink<?> tableSink)
Deprecated.
Use
executeSql(ddl) to register a table instead. |
void |
registerTableSink(String name,
TableSink<?> configuredSink)
Deprecated.
Use
executeSql(ddl) to register a table instead. |
void |
registerTableSource(String name,
TableSource<?> tableSource)
Deprecated.
Use
executeSql(ddl) to register a table instead. |
Table |
scan(String... tablePath)
Deprecated.
use
from(String) |
Table |
sqlQuery(String query)
Evaluates a SQL query on registered tables and retrieves the result as a
Table . |
void |
sqlUpdate(String stmt)
Deprecated.
use
executeSql(String) for single statement, use createStatementSet() for multiple DML statements. |
void |
unloadModule(String moduleName)
Unloads a
Module with given name. |
void |
useCatalog(String catalogName)
Sets the current catalog to the given value.
|
void |
useDatabase(String databaseName)
Sets the current default database.
|
static TableEnvironment create(EnvironmentSettings settings)
It is unified both on a language level for all JVM-based languages (i.e. there is no distinction between Scala and Java API) and for bounded and unbounded data processing.
A table environment is responsible for:
Table
s and other meta objects from a catalog.
Note: This environment is meant for pure table programs. If you would like to convert from or to other Flink APIs, it might be necessary to use one of the available language-specific table environments in the corresponding bridging modules.
settings
- The environment settings used to instantiate the TableEnvironment
.default Table fromValues(Object... values)
Examples:
You can use a row(...)
expression to create a composite rows:
tEnv.fromValues(
row(1, "ABC"),
row(2L, "ABCDE")
)
will produce a Table with a schema as follows:
root
|-- f0: BIGINT NOT NULL // original types INT and BIGINT are generalized to BIGINT
|-- f1: VARCHAR(5) NOT NULL // original types CHAR(3) and CHAR(5) are generalized to VARCHAR(5)
// it uses VARCHAR instead of CHAR so that no padding is applied
The method will derive the types automatically from the input expressions. If types at a
certain position differ, the method will try to find a common super type for all types. If a
common super type does not exist, an exception will be thrown. If you want to specify the
requested type explicitly see fromValues(AbstractDataType, Object...)
.
It is also possible to use Row
object instead of row
expressions.
ROWs that are a result of e.g. a function call are not flattened
public class RowFunction extends ScalarFunction {
{@literal @}DataTypeHint("ROW<f0 BIGINT, f1 VARCHAR(5)>")
Row eval();
}
tEnv.fromValues(
call(new RowFunction()),
call(new RowFunction())
)
will produce a Table with a schema as follows:
root
|-- f0: ROW<`f0` BIGINT, `f1` VARCHAR(5)>
The row constructor can be dropped to create a table with a single column:
ROWs that are a result of e.g. a function call are not flattened
tEnv.fromValues(
1,
2L,
3
)
will produce a Table with a schema as follows:
root
|-- f0: BIGINT NOT NULL
values
- Expressions for constructing rows of the VALUES table.default Table fromValues(AbstractDataType<?> rowType, Object... values)
The difference between this method and fromValues(Object...)
is that the schema
can be manually adjusted. It might be helpful for assigning more generic types like e.g.
DECIMAL or naming the columns.
Examples:
tEnv.fromValues(
DataTypes.ROW(
DataTypes.FIELD("id", DataTypes.DECIMAL(10, 2)),
DataTypes.FIELD("name", DataTypes.STRING())
),
row(1, "ABC"),
row(2L, "ABCDE")
)
will produce a Table with a schema as follows:
root
|-- id: DECIMAL(10, 2)
|-- f1: STRING
For more examples see fromValues(Object...)
.
rowType
- Expected row type for the values.values
- Expressions for constructing rows of the VALUES table.fromValues(Object...)
Table fromValues(Expression... values)
Examples:
You can use a row(...)
expression to create a composite rows:
tEnv.fromValues(
row(1, "ABC"),
row(2L, "ABCDE")
)
will produce a Table with a schema as follows:
root
|-- f0: BIGINT NOT NULL // original types INT and BIGINT are generalized to BIGINT
|-- f1: VARCHAR(5) NOT NULL // original types CHAR(3) and CHAR(5) are generalized to VARCHAR(5)
* // it uses VARCHAR instead of CHAR so that no padding is applied
The method will derive the types automatically from the input expressions. If types at a
certain position differ, the method will try to find a common super type for all types. If a
common super type does not exist, an exception will be thrown. If you want to specify the
requested type explicitly see #fromValues(DataType, Expression...)
.
It is also possible to use Row
object instead of row
expressions.
ROWs that are a result of e.g. a function call are not flattened
public class RowFunction extends ScalarFunction {
{@literal @}DataTypeHint("ROW<f0 BIGINT, f1 VARCHAR(5)>")
Row eval();
}
tEnv.fromValues(
call(new RowFunction()),
call(new RowFunction())
)
will produce a Table with a schema as follows:
root
|-- f0: ROW<`f0` BIGINT, `f1` VARCHAR(5)>
The row constructor can be dropped to create a table with a single column:
ROWs that are a result of e.g. a function call are not flattened
tEnv.fromValues(
lit(1).plus(2),
lit(2L),
lit(3)
)
will produce a Table with a schema as follows:
root
|-- f0: BIGINT NOT NULL
values
- Expressions for constructing rows of the VALUES table.Table fromValues(AbstractDataType<?> rowType, Expression... values)
The difference between this method and fromValues(Expression...)
is that the
schema can be manually adjusted. It might be helpful for assigning more generic types like
e.g. DECIMAL or naming the columns.
Examples:
tEnv.fromValues(
DataTypes.ROW(
DataTypes.FIELD("id", DataTypes.DECIMAL(10, 2)),
DataTypes.FIELD("name", DataTypes.STRING())
),
row(1, "ABC"),
row(2L, "ABCDE")
)
will produce a Table with a schema as follows:
root
|-- id: DECIMAL(10, 2)
|-- name: STRING
For more examples see fromValues(Expression...)
.
rowType
- Expected row type for the values.values
- Expressions for constructing rows of the VALUES table.fromValues(Expression...)
Table fromValues(Iterable<?> values)
See fromValues(Object...)
for more explanation.
values
- Expressions for constructing rows of the VALUES table.fromValues(Object...)
Table fromValues(AbstractDataType<?> rowType, Iterable<?> values)
See fromValues(AbstractDataType, Object...)
for more explanation.
rowType
- Expected row type for the values.values
- Expressions for constructing rows of the VALUES table.fromValues(AbstractDataType, Object...)
@Deprecated Table fromTableSource(TableSource<?> source)
source
- table source used as tablevoid registerCatalog(String catalogName, Catalog catalog)
catalogName
- The name under which the catalog will be registered.catalog
- The catalog to register.Optional<Catalog> getCatalog(String catalogName)
Catalog
by name.catalogName
- The name to look up the Catalog
.void loadModule(String moduleName, Module module)
Module
under a unique name. Modules will be kept in the loaded order.
ValidationException is thrown when there is already a module with the same name.moduleName
- name of the Module
module
- the module instancevoid unloadModule(String moduleName)
Module
with given name. ValidationException is thrown when there is no
module with the given namemoduleName
- name of the Module
@Deprecated void registerFunction(String name, ScalarFunction function)
createTemporarySystemFunction(String, UserDefinedFunction)
instead.
Please note that the new method also uses the new type system and reflective extraction
logic. It might be necessary to update the function implementation as well. See the
documentation of ScalarFunction
for more information on the new function design.ScalarFunction
under a unique name. Replaces already existing
user-defined functions under this name.@Experimental void createTemporarySystemFunction(String name, Class<? extends UserDefinedFunction> functionClass)
UserDefinedFunction
class as a temporary system function.
Compared to createTemporaryFunction(String, Class)
, system functions are
identified by a global name that is independent of the current catalog and current database.
Thus, this method allows to extend the set of built-in system functions like TRIM
,
ABS
, etc.
Temporary functions can shadow permanent ones. If a permanent function under a given name exists, it will be inaccessible in the current session. To make the permanent function available again one can drop the corresponding temporary system function.
name
- The name under which the function will be registered globally.functionClass
- The function class containing the implementation.@Experimental void createTemporarySystemFunction(String name, UserDefinedFunction functionInstance)
UserDefinedFunction
instance as a temporary system function.
Compared to createTemporarySystemFunction(String, Class)
, this method takes a
function instance that might have been parameterized before (e.g. through its constructor).
This might be useful for more interactive sessions. Make sure that the instance is Serializable
.
Compared to createTemporaryFunction(String, UserDefinedFunction)
, system
functions are identified by a global name that is independent of the current catalog and
current database. Thus, this method allows to extend the set of built-in system functions
like TRIM
, ABS
, etc.
Temporary functions can shadow permanent ones. If a permanent function under a given name exists, it will be inaccessible in the current session. To make the permanent function available again one can drop the corresponding temporary system function.
name
- The name under which the function will be registered globally.functionInstance
- The (possibly pre-configured) function instance containing the
implementation.@Experimental boolean dropTemporarySystemFunction(String name)
If a permanent function with the given name exists, it will be used from now on for any queries that reference this name.
name
- The name under which the function has been registered globally.@Experimental void createFunction(String path, Class<? extends UserDefinedFunction> functionClass)
UserDefinedFunction
class as a catalog function in the given path.
Compared to system functions with a globally defined name, catalog functions are always (implicitly or explicitly) identified by a catalog and database.
There must not be another function (temporary or permanent) registered under the same path.
path
- The path under which the function will be registered. See also the TableEnvironment
class description for the format of the path.functionClass
- The function class containing the implementation.@Experimental void createFunction(String path, Class<? extends UserDefinedFunction> functionClass, boolean ignoreIfExists)
UserDefinedFunction
class as a catalog function in the given path.
Compared to system functions with a globally defined name, catalog functions are always (implicitly or explicitly) identified by a catalog and database.
path
- The path under which the function will be registered. See also the TableEnvironment
class description for the format of the path.functionClass
- The function class containing the implementation.ignoreIfExists
- If a function exists under the given path and this flag is set, no
operation is executed. An exception is thrown otherwise.@Experimental boolean dropFunction(String path)
path
- The path under which the function has been registered. See also the TableEnvironment
class description for the format of the path.@Experimental void createTemporaryFunction(String path, Class<? extends UserDefinedFunction> functionClass)
UserDefinedFunction
class as a temporary catalog function.
Compared to createTemporarySystemFunction(String, Class)
with a globally defined
name, catalog functions are always (implicitly or explicitly) identified by a catalog and
database.
Temporary functions can shadow permanent ones. If a permanent function under a given name exists, it will be inaccessible in the current session. To make the permanent function available again one can drop the corresponding temporary function.
path
- The path under which the function will be registered. See also the TableEnvironment
class description for the format of the path.functionClass
- The function class containing the implementation.@Experimental void createTemporaryFunction(String path, UserDefinedFunction functionInstance)
UserDefinedFunction
instance as a temporary catalog function.
Compared to createTemporaryFunction(String, Class)
, this method takes a function
instance that might have been parameterized before (e.g. through its constructor). This might
be useful for more interactive sessions. Make sure that the instance is Serializable
.
Compared to createTemporarySystemFunction(String, UserDefinedFunction)
with a
globally defined name, catalog functions are always (implicitly or explicitly) identified by
a catalog and database.
Temporary functions can shadow permanent ones. If a permanent function under a given name exists, it will be inaccessible in the current session. To make the permanent function available again one can drop the corresponding temporary function.
path
- The path under which the function will be registered. See also the TableEnvironment
class description for the format of the path.functionInstance
- The (possibly pre-configured) function instance containing the
implementation.@Experimental boolean dropTemporaryFunction(String path)
If a permanent function with the given path exists, it will be used from now on for any queries that reference this path.
path
- The path under which the function will be registered. See also the TableEnvironment
class description for the format of the path.@Deprecated void registerTable(String name, Table table)
createTemporaryView(String, Table)
Table
under a unique name in the TableEnvironment's catalog. Registered
tables can be referenced in SQL queries.
Temporary objects can shadow permanent ones. If a permanent object in a given path exists, it will be inaccessible in the current session. To make the permanent object available again one can drop the corresponding temporary object.
name
- The name under which the table will be registered.table
- The table to register.void createTemporaryView(String path, Table view)
Table
API object as a temporary view similar to SQL temporary views.
Temporary objects can shadow permanent ones. If a permanent object in a given path exists, it will be inaccessible in the current session. To make the permanent object available again one can drop the corresponding temporary object.
path
- The path under which the view will be registered. See also the TableEnvironment
class description for the format of the path.view
- The view to register.@Deprecated void registerTableSource(String name, TableSource<?> tableSource)
executeSql(ddl)
to register a table instead.TableSource
in this TableEnvironment
's catalog.
Registered tables can be referenced in SQL queries.
Temporary objects can shadow permanent ones. If a permanent object in a given path exists, it will be inaccessible in the current session. To make the permanent object available again one can drop the corresponding temporary object.
name
- The name under which the TableSource
is registered.tableSource
- The TableSource
to register.@Deprecated void registerTableSink(String name, String[] fieldNames, TypeInformation<?>[] fieldTypes, TableSink<?> tableSink)
executeSql(ddl)
to register a table instead.TableSink
with given field names and types in this TableEnvironment
's catalog. Registered sink tables can be referenced in SQL DML statements.
Temporary objects can shadow permanent ones. If a permanent object in a given path exists, it will be inaccessible in the current session. To make the permanent object available again one can drop the corresponding temporary object.
@Deprecated void registerTableSink(String name, TableSink<?> configuredSink)
executeSql(ddl)
to register a table instead.TableSink
with already configured field names and field types
in this TableEnvironment
's catalog. Registered sink tables can be referenced in SQL
DML statements.
Temporary objects can shadow permanent ones. If a permanent object in a given path exists, it will be inaccessible in the current session. To make the permanent object available again one can drop the corresponding temporary object.
@Deprecated Table scan(String... tablePath)
from(String)
Table
.
A table to scan must be registered in the TableEnvironment
. It can be either
directly registered or be an external member of a Catalog
.
See the documentation of useDatabase(String)
or useCatalog(String)
for the rules on the path resolution.
Examples:
Scanning a directly registered table.
Table tab = tableEnv.scan("tableName");
Scanning a table from a registered catalog.
Table tab = tableEnv.scan("catalogName", "dbName", "tableName");
tablePath
- The path of the table to scan.Table
.useCatalog(String)
,
useDatabase(String)
Table from(String path)
Table
.
A table to scan must be registered in the TableEnvironment
.
See the documentation of useDatabase(String)
or useCatalog(String)
for the rules on the path resolution.
Examples:
Reading a table from default catalog and database.
Table tab = tableEnv.from("tableName");
Reading a table from a registered catalog.
Table tab = tableEnv.from("catalogName.dbName.tableName");
Reading a table from a registered catalog with escaping. Dots in e.g. a database name must be escaped.
Table tab = tableEnv.from("catalogName.`db.Name`.Table");
path
- The path of a table API object to scan.useCatalog(String)
,
useDatabase(String)
@Deprecated void insertInto(Table table, String sinkPath, String... sinkPathContinued)
Table.executeInsert(String)
for single sink, use createStatementSet()
for multiple sinks.Table
to a TableSink
that was registered under the specified name.
See the documentation of useDatabase(String)
or useCatalog(String)
for the rules on the path resolution.
table
- The Table to write to the sink.sinkPath
- The first part of the path of the registered TableSink
to which the
Table
is written. This is to ensure at least the name of the TableSink
is
provided.sinkPathContinued
- The remaining part of the path of the registered TableSink
to which the Table
is written.@Deprecated void insertInto(String targetPath, Table table)
Table.executeInsert(String)
for single sink, use createStatementSet()
for multiple sinks.Table
API object into a table.
See the documentation of useDatabase(String)
or useCatalog(String)
for the rules on the path resolution.
@Deprecated ConnectTableDescriptor connect(ConnectorDescriptor connectorDescriptor)
CREATE TABLE
DDL is richer than this part of the API. This method
might be refactored in the next versions. Please use executeSql(ddl)
to register a table instead.Descriptors allow for declaring the communication to external systems in an implementation-agnostic way. The classpath is scanned for suitable table factories that match the desired configuration.
The following example shows how to read from a connector using a JSON format and register a temporary table as "MyTable":
tableEnv
.connect(
new ExternalSystemXYZ()
.version("0.11"))
.withFormat(
new Json()
.jsonSchema("{...}")
.failOnMissingField(false))
.withSchema(
new Schema()
.field("user-name", "VARCHAR").from("u_name")
.field("count", "DECIMAL")
.createTemporaryTable("MyTable");
connectorDescriptor
- connector descriptor describing the external systemString[] listCatalogs()
String[] listModules()
String[] listDatabases()
String[] listTables()
listTemporaryTables()
,
listTemporaryViews()
String[] listViews()
listTemporaryViews()
String[] listTemporaryTables()
listTables()
String[] listTemporaryViews()
listTables()
String[] listUserDefinedFunctions()
String[] listFunctions()
boolean dropTemporaryTable(String path)
If a permanent table with a given path exists, it will be used from now on for any queries that reference this path.
boolean dropTemporaryView(String path)
If a permanent table or view with a given path exists, it will be used from now on for any queries that reference this path.
@Deprecated String explain(Table table)
Table.explain(ExplainDetail...)
.Table
.table
- The table for which the AST and execution plan will be returned.@Deprecated String explain(Table table, boolean extended)
Table.explain(ExplainDetail...)
.Table
.table
- The table for which the AST and execution plan will be returned.extended
- if the plan should contain additional properties, e.g. estimated cost, traits@Deprecated String explain(boolean extended)
StatementSet.explain(ExplainDetail...)
.extended
- if the plan should contain additional properties, e.g. estimated cost, traitsString explainSql(String statement, ExplainDetail... extraDetails)
statement
- The statement for which the AST and execution plan will be returned.extraDetails
- The extra explain details which the explain result should include, e.g.
estimated cost, changelog mode for streaming@Deprecated String[] getCompletionHints(String statement, int position)
statement
- Partial or slightly incorrect SQL statementposition
- cursor positionTable sqlQuery(String query)
Table
.
All tables referenced by the query must be registered in the TableEnvironment. A Table
is automatically registered when its Table#toString()
method is called, for
example when it is embedded into a String. Hence, SQL queries can directly reference a Table
as follows:
Table table = ...;
String tableName = table.toString();
// the table is not registered to the table environment
tEnv.sqlQuery("SELECT * FROM tableName");
query
- The SQL query to evaluate.TableResult executeSql(String statement)
The statement can be DDL/DML/DQL/SHOW/DESCRIBE/EXPLAIN/USE. For DML and DQL, this method returns TableResult once the job has been submitted. For DDL and DCL statements, TableResult is returned once the operation has finished.
@Deprecated void sqlUpdate(String stmt)
executeSql(String)
for single statement, use createStatementSet()
for multiple DML statements.All tables referenced by the query must be registered in the TableEnvironment. A Table
is automatically registered when its Table#toString()
method is called, for
example when it is embedded into a String. Hence, SQL queries can directly reference a Table
as follows:
// register the configured table sink into which the result is inserted.
tEnv.registerTableSinkInternal("sinkTable", configuredSink);
Table sourceTable = ...
String tableName = sourceTable.toString();
// sourceTable is not registered to the table environment
tEnv.sqlUpdate(s"INSERT INTO sinkTable SELECT * FROM tableName");
A DDL statement can also be executed to create a table: For example, the below DDL statement would create a CSV table named `tbl1` into the current catalog:
create table tbl1( a int, b bigint, c varchar ) with ( 'connector.type' = 'filesystem', 'format.type' = 'csv', 'connector.path' = 'xxx' )
SQL queries can directly execute as follows:
String sinkDDL = "create table sinkTable( a int, b varchar ) with ( 'connector.type' = 'filesystem', 'format.type' = 'csv', 'connector.path' = 'xxx' )"; String sourceDDL ="create table sourceTable( a int, b varchar ) with ( 'connector.type' = 'kafka', 'update-mode' = 'append', 'connector.topic' = 'xxx', 'connector.properties.bootstrap.servers' = 'localhost:9092', ... )"; String query = "INSERT INTO sinkTable SELECT * FROM sourceTable"; tEnv.sqlUpdate(sourceDDL); tEnv.sqlUpdate(sinkDDL); tEnv.sqlUpdate(query); tEnv.execute("MyJob");
This code snippet creates a job to read data from Kafka source into a CSV sink.
stmt
- The SQL statement to evaluate.String getCurrentCatalog()
useCatalog(String)
void useCatalog(String catalogName)
useDatabase(String)
.
This is used during the resolution of object paths. Both the catalog and database are optional when referencing catalog objects such as tables, views etc. The algorithm looks for requested objects in following paths in that order:
[current-catalog].[current-database].[requested-path]
[current-catalog].[requested-path]
[requested-path]
Example:
Given structure with default catalog set to default_catalog
and default database
set to default_database
.
root: |- default_catalog |- default_database |- tab1 |- db1 |- tab1 |- cat1 |- db1 |- tab1
The following table describes resolved paths:
Requested path | Resolved path |
---|---|
tab1 | default_catalog.default_database.tab1 |
db1.tab1 | default_catalog.db1.tab1 |
cat1.db1.tab1 | cat1.db1.tab1 |
catalogName
- The name of the catalog to set as the current default catalog.useDatabase(String)
String getCurrentDatabase()
useDatabase(String)
void useDatabase(String databaseName)
This is used during the resolution of object paths. Both the catalog and database are optional when referencing catalog objects such as tables, views etc. The algorithm looks for requested objects in following paths in that order:
[current-catalog].[current-database].[requested-path]
[current-catalog].[requested-path]
[requested-path]
Example:
Given structure with default catalog set to default_catalog
and default database
set to default_database
.
root: |- default_catalog |- default_database |- tab1 |- db1 |- tab1 |- cat1 |- db1 |- tab1
The following table describes resolved paths:
Requested path | Resolved path |
---|---|
tab1 | default_catalog.default_database.tab1 |
db1.tab1 | default_catalog.db1.tab1 |
cat1.db1.tab1 | cat1.db1.tab1 |
databaseName
- The name of the database to set as the current database.useCatalog(String)
TableConfig getConfig()
@Deprecated JobExecutionResult execute(String jobName) throws Exception
executeSql(String)
or Table.executeInsert(String)
for single
sink, use createStatementSet()
for multiple sinks.The program execution will be logged and displayed with the provided name
NOTE:It is highly advised to set all parameters in the TableConfig
on the
very beginning of the program. It is undefined what configurations values will be used for
the execution if queries are mixed with config changes. It depends on the characteristic of
the particular parameter. For some of them the value from the point in time of query
construction (e.g. the currentCatalog) will be used. On the other hand some values might be
evaluated according to the state from the time when this method is called (e.g. timeZone).
Once the execution finishes, any previously defined DMLs will be cleared, no matter
whether the execution succeeds or not. Therefore, if you want to retry in case of failures,
you have to re-define the DMLs, i.e. by calling sqlUpdate(String)
, before you call
this method again.
jobName
- Desired name of the jobException
- which occurs during job execution.StatementSet createStatementSet()
StatementSet
instance which accepts DML statements or Tables, the planner
can optimize all added statements and Tables together and then submit as one job.Copyright © 2014–2021 The Apache Software Foundation. All rights reserved.