This documentation is for an out-of-date version of Apache Flink. We recommend you use the latest stable version.

SHOW Statements

SHOW statements are used to list all catalogs, or list all databases in the current catalog, or list all tables/views in the current catalog and the current database, or list all functions including temp system functions, system functions, temp catalog functions and catalog functions in the current catalog and the current database.

Flink SQL supports the following SHOW statements for now:

  • SHOW CATALOGS
  • SHOW DATABASES
  • SHOW TABLES
  • SHOW VIEWS
  • SHOW FUNCTIONS

Run a SHOW statement

SHOW statements can be executed with the executeSql() method of the TableEnvironment, or executed in SQL CLI. The executeSql() method returns objects for a successful SHOW operation, otherwise will throw an exception.

The following examples show how to run a SHOW statement in TableEnvironment and in SQL CLI.

StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
StreamTableEnvironment tEnv = StreamTableEnvironment.create(env);

// show catalogs
tEnv.executeSql("SHOW CATALOGS").print();
// +-----------------+
// |    catalog name |
// +-----------------+
// | default_catalog |
// +-----------------+

// show databases
tEnv.executeSql("SHOW DATABASES").print();
// +------------------+
// |    database name |
// +------------------+
// | default_database |
// +------------------+

// create a table
tEnv.executeSql("CREATE TABLE my_table (...) WITH (...)");
// show tables
tEnv.executeSql("SHOW TABLES").print();
// +------------+
// | table name |
// +------------+
// |   my_table |
// +------------+

// create a view
tEnv.executeSql("CREATE VIEW my_view AS ...");
// show views
tEnv.executeSql("SHOW VIEWS").print();
// +-----------+
// | view name |
// +-----------+
// |   my_view |
// +-----------+

// show functions
tEnv.executeSql("SHOW FUNCTIONS").print();
// +---------------+
// | function name |
// +---------------+
// |           mod |
// |        sha256 |
// |           ... |
// +---------------+
val env = StreamExecutionEnvironment.getExecutionEnvironment()
val tEnv = StreamTableEnvironment.create(env)

// show catalogs
tEnv.executeSql("SHOW CATALOGS").print()
// +-----------------+
// |    catalog name |
// +-----------------+
// | default_catalog |
// +-----------------+

// show databases
tEnv.executeSql("SHOW DATABASES").print()
// +------------------+
// |    database name |
// +------------------+
// | default_database |
// +------------------+

// create a table
tEnv.executeSql("CREATE TABLE my_table (...) WITH (...)")
// show tables
tEnv.executeSql("SHOW TABLES").print()
// +------------+
// | table name |
// +------------+
// |   my_table |
// +------------+

// create a view
tEnv.executeSql("CREATE VIEW my_view AS ...")
// show views
tEnv.executeSql("SHOW VIEWS").print()
// +-----------+
// | view name |
// +-----------+
// |   my_view |
// +-----------+

// show functions
tEnv.executeSql("SHOW FUNCTIONS").print()
// +---------------+
// | function name |
// +---------------+
// |           mod |
// |        sha256 |
// |           ... |
// +---------------+
settings = EnvironmentSettings.new_instance()...
table_env = StreamTableEnvironment.create(env, settings)

# show catalogs
table_env.execute_sql("SHOW CATALOGS").print()
# +-----------------+
# |    catalog name |
# +-----------------+
# | default_catalog |
# +-----------------+

# show databases
table_env.execute_sql("SHOW DATABASES").print()
# +------------------+
# |    database name |
# +------------------+
# | default_database |
# +------------------+

# create a table
table_env.execute_sql("CREATE TABLE my_table (...) WITH (...)")
# show tables
table_env.execute_sql("SHOW TABLES").print()
# +------------+
# | table name |
# +------------+
# |   my_table |
# +------------+

# create a view
table_env.execute_sql("CREATE VIEW my_view AS ...")
# show views
table_env.execute_sql("SHOW VIEWS").print()
# +-----------+
# | view name |
# +-----------+
# |   my_view |
# +-----------+

# show functions
table_env.execute_sql("SHOW FUNCTIONS").print()
# +---------------+
# | function name |
# +---------------+
# |           mod |
# |        sha256 |
# |           ... |
# +---------------+
Flink SQL> SHOW CATALOGS;
default_catalog

Flink SQL> SHOW DATABASES;
default_database

Flink SQL> CREATE TABLE my_table (...) WITH (...);
[INFO] Table has been created.

Flink SQL> SHOW TABLES;
my_table

Flink SQL> CREATE VIEW my_view AS ...;
[INFO] View has been created.

Flink SQL> SHOW VIEWS;
my_view

Flink SQL> SHOW FUNCTIONS;
mod
sha256
...

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SHOW CATALOGS

SHOW CATALOGS

Show all catalogs.

SHOW DATABASES

SHOW DATABASES

Show all databases in the current catalog.

SHOW TABLES

SHOW TABLES

Show all tables in the current catalog and the current database.

SHOW VIEWS

SHOW VIEWS

Show all views in the current catalog and the current database.

SHOW FUNCTIONS

SHOW FUNCTIONS

Show all functions including temp system functions, system functions, temp catalog functions and catalog functions in the current catalog and current database.