USE Statements
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USE Statements #

USE statements are used to set the current database or catalog, or change the resolution order and enabled status of module.

Run a USE statement #

USE statements can be executed with the executeSql() method of the TableEnvironment. The executeSql() method returns ‘OK’ for a successful USE operation, otherwise will throw an exception.

The following examples show how to run a USE statement in TableEnvironment.

USE statements can be executed with the executeSql() method of the TableEnvironment. The executeSql() method returns ‘OK’ for a successful USE operation, otherwise will throw an exception.

The following examples show how to run a USE statement in TableEnvironment.

USE statements can be executed with the execute_sql() method of the TableEnvironment. The execute_sql() method returns ‘OK’ for a successful USE operation, otherwise will throw an exception.

The following examples show how to run a USE statement in TableEnvironment.

USE statements can be executed in SQL CLI.

The following examples show how to run a USE statement in SQL CLI.

StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment(); StreamTableEnvironment tEnv = StreamTableEnvironment.create(env);  // create a catalog tEnv.executeSql("CREATE CATALOG cat1 WITH (...)"); tEnv.executeSql("SHOW CATALOGS").print(); // +-----------------+ // | catalog name | // +-----------------+ // | default_catalog | // | cat1 | // +-----------------+  // change default catalog tEnv.executeSql("USE CATALOG cat1");  tEnv.executeSql("SHOW DATABASES").print(); // databases are empty // +---------------+ // | database name | // +---------------+ // +---------------+  // create a database tEnv.executeSql("CREATE DATABASE db1 WITH (...)"); tEnv.executeSql("SHOW DATABASES").print(); // +---------------+ // | database name | // +---------------+ // | db1 | // +---------------+  // change default database tEnv.executeSql("USE db1");  // change module resolution order and enabled status tEnv.executeSql("USE MODULES hive"); tEnv.executeSql("SHOW FULL MODULES").print(); // +-------------+-------+ // | module name | used | // +-------------+-------+ // | hive | true | // | core | false | // +-------------+-------+ 
val env = StreamExecutionEnvironment.getExecutionEnvironment() val tEnv = StreamTableEnvironment.create(env)  // create a catalog tEnv.executeSql("CREATE CATALOG cat1 WITH (...)") tEnv.executeSql("SHOW CATALOGS").print() // +-----------------+ // | catalog name | // +-----------------+ // | default_catalog | // | cat1 | // +-----------------+  // change default catalog tEnv.executeSql("USE CATALOG cat1")  tEnv.executeSql("SHOW DATABASES").print() // databases are empty // +---------------+ // | database name | // +---------------+ // +---------------+  // create a database tEnv.executeSql("CREATE DATABASE db1 WITH (...)") tEnv.executeSql("SHOW DATABASES").print() // +---------------+ // | database name | // +---------------+ // | db1 | // +---------------+  // change default database tEnv.executeSql("USE db1")  // change module resolution order and enabled status tEnv.executeSql("USE MODULES hive") tEnv.executeSql("SHOW FULL MODULES").print() // +-------------+-------+ // | module name | used | // +-------------+-------+ // | hive | true | // | core | false | // +-------------+-------+ 
table_env = StreamTableEnvironment.create(...)  # create a catalog table_env.execute_sql("CREATE CATALOG cat1 WITH (...)") table_env.execute_sql("SHOW CATALOGS").print() # +-----------------+ # | catalog name | # +-----------------+ # | default_catalog | # | cat1 | # +-----------------+  # change default catalog table_env.execute_sql("USE CATALOG cat1")  table_env.execute_sql("SHOW DATABASES").print() # databases are empty # +---------------+ # | database name | # +---------------+ # +---------------+  # create a database table_env.execute_sql("CREATE DATABASE db1 WITH (...)") table_env.execute_sql("SHOW DATABASES").print() # +---------------+ # | database name | # +---------------+ # | db1 | # +---------------+  # change default database table_env.execute_sql("USE db1")  # change module resolution order and enabled status table_env.execute_sql("USE MODULES hive") table_env.execute_sql("SHOW FULL MODULES").print() # +-------------+-------+ # | module name | used | # +-------------+-------+ # | hive | true | # | core | false | # +-------------+-------+ 
Flink SQL> CREATE CATALOG cat1 WITH (...); [INFO] Catalog has been created.  Flink SQL> SHOW CATALOGS; default_catalog cat1  Flink SQL> USE CATALOG cat1;  Flink SQL> SHOW DATABASES;  Flink SQL> CREATE DATABASE db1 WITH (...); [INFO] Database has been created.  Flink SQL> SHOW DATABASES; db1  Flink SQL> USE db1;  Flink SQL> USE MODULES hive; [INFO] Use modules succeeded! Flink SQL> SHOW FULL MODULES; +-------------+-------+ | module name | used | +-------------+-------+ | hive | true | | core | false | +-------------+-------+ 2 rows in set

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USE CATALOG # 

USE CATALOG catalog_name

Set the current catalog. All subsequent commands that do not explicitly specify a catalog will use this one. If the provided catalog does not exist, an exception is thrown. The default current catalog is default_catalog.

USE MODULES # 

USE MODULES module_name1[, module_name2, ...]

Set the enabled modules with declared order. All subsequent commands will resolve metadata(functions/user-defined types/rules, etc.) within enabled modules and follow resolution order. A module is used by default when it is loaded. Loaded modules will become disabled if not used by USE MODULES statement. The default loaded and enabled module is core.

USE # 

USE [catalog_name.]database_name

Set the current database. All subsequent commands that do not explicitly specify a database will use this one. If the provided database does not exist, an exception is thrown. The default current database is default_database.