INT DEFAULT 0;
    DECLARE v_table_exists ENUM('', 'BASE TABLE', 'VIEW', 'TEMPORARY') DEFAULT '';
    DECLARE db_doesnt_exist CONDITION FOR SQLSTATE '42000';
    DECLARE db_name_exists CONDITION FOR SQLSTATE 'HY000';
    DECLARE c_table_names CURSOR FOR
        SELECT TABLE_NAME
          FROM INFORMATION_SCHEMA.TABLES
         WHERE TABLE_SCHEMA = in_db_name;
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET v_done = TRUE;
    SELECT SCHEMA_NAME INTO v_db_name_check
      FROM INFORMATION_SCHEMA.SCHEMATA
     WHERE SCHEMA_NAME = in_db_name;
    IF v_db_name_check IS NULL THEN
        SET v_db_err_msg = CONCAT('Unknown database ', in_db_name);
        SIGNAL SQLSTATE 'HY000'
            SET MESSAGE_TEXT = v_db_err_msg;
    END IF;
    SELECT SCHEMA_NAME INTO v_db_name_check
      FROM INFORMATION_SCHEMA.SCHEMATA
     WHERE SCHEMA_NAME = in_synonym;
    IF v_db_name_check = in_synonym THEN
        SET v_db_err_msg = CONCAT('Can\'t create database ', in_synonym, '; database exists');
        SIGNAL SQLSTATE 'HY000'
            SET MESSAGE_TEXT = v_db_err_msg;
    END IF;
    SET @create_db_stmt := CONCAT('CREATE DATABASE ', sys.quote_identifier(in_synonym));
    PREPARE create_db_stmt FROM @create_db_stmt;
    EXECUTE create_db_stmt;
    DEALLOCATE PREPARE create_db_stmt;
    SET v_done = FALSE;
    OPEN c_table_names;
    c_table_names: LOOP
        FETCH c_table_names INTO v_table;
        IF v_done THEN
            LEAVE c_table_names;
        END IF;
        CALL sys.table_exists(in_db_name, v_table, v_table_exists);
        IF (v_table_exists <> 'TEMPORARY') THEN
            SET @create_view_stmt = CONCAT(
                'CREATE SQL SECURITY INVOKER VIEW ',
                sys.quote_identifier(in_synonym),
                '.',
                sys.quote_identifier(v_table),
                ' AS SELECT * FROM ',
                sys.quote_identifier(in_db_name),
                '.',
                sys.quote_identifier(v_table)
            );
            PREPARE create_view_stmt FROM @create_view_stmt;
            EXECUTE create_view_stmt;
            DEALLOCATE PREPARE create_view_stmt;
            SET v_views_created = v_views_created + 1;
        END IF;
    END LOOP;
    CLOSE c_table_names;
    SELECT CONCAT(
        'Created ', v_views_created, ' view',
        IF(v_views_created != 1, 's', ''), ' in the ',
        sys.quote_identifier(in_synonym), ' database'
    ) AS summary;
END
             Description
             Takes a source database name and synonym name, and then creates the
             synonym database with views that point to all of the tables within
             the source database.
             Useful for creating a "ps" synonym for "performance_schema",
             or "is" instead of "information_schema", for example.
             Parameters
             in_db_name (VARCHAR(64)):
               The database name that you would like to create a synonym for.
             in_synonym (VARCHAR(64)):
               The database synonym name.
             Example
             mysql> SHOW DATABASES;
             +--------------------+
             | Database           |
             +--------------------+
             | information_schema |
             | mysql              |
             | performance_schema |
             | sys                |
             | test               |
             +--------------------+
             5 rows in set (0.00 sec)
             mysql> CALL sys.create_synonym_db('performance_schema', 'ps');
             +---------------------------------------+
             | summary                               |
             +---------------------------------------+
             | Created 74 views in the `ps` database |
             +---------------------------------------+
             1 row in set (8.57 sec)
             Query OK, 0 rows affected (8.57 sec)
             mysql> SHOW DATABASES;
             +--------------------+
             | Database           |
             +--------------------+
             | information_schema |
             | mysql              |