title: Error in SQL Developer during creating tables
body: <p>I'm trying to create 3 tables using SQL Developer and have an error. Can't undersand why it happens.</p>
  
  <pre><code>Create table Album
  (
    "alb_code" integer primary key,
    "alb_name" char(50),
    "publ" char(50),
    "publ_date" date not null
  );
  Create table Song
  (
    "song_code" integer primary key,
    "song_name" char(50),
    "auth" char(50),
    "year" integer,
    "style" char(30)
  );
  Create table Song_from_Album
  (
    "in_alb_code" integer primary key,
    "time" float,
    "no" integer,
    FOREIGN KEY REFERENCES Song("song_code"),
    FOREIGN KEY REFERENCES Album("alb_code")
  );
  </code></pre>
  
  <p>I get an error:</p>
  
  <pre><code>Error starting at line : 1 in command -
  Create table Album
  (
    "alb_code" integer primary key,
    "alb_name" char(50),
    "publ" char(50),
    "publ_date" date not null
  )
  Error at Command Line : 1 Column : 14
  Error report -
  SQL Error: ORA-00955: имя уже задействовано для существующего объекта
  00955. 00000 -  "name is already used by an existing object"
  *Cause:    
  *Action:
  
  Error starting at line : 8 in command -
  Create table Song
  (
    "song_code" integer primary key,
    "song_name" char(50),
    "auth" char(50),
    "year" integer,
    "style" char(30)
  )
  Error at Command Line : 8 Column : 14
  Error report -
  SQL Error: ORA-00955: имя уже задействовано для существующего объекта
  00955. 00000 -  "name is already used by an existing object"
  *Cause:    
  *Action:
  
  Error starting at line : 16 in command -
  Create table Song_from_Album
  (
    "in_alb_code" integer primary key,
    "time" float,
    "no" integer,
    FOREIGN KEY REFERENCES Song("song_code"),
    FOREIGN KEY REFERENCES Album("alb_code")
  )
  Error at Command Line : 21 Column : 15
  Error report -
  SQL Error: ORA-00906: отсутствует левая скобка
  00906. 00000 -  "missing left parenthesis"
  *Cause:    
  *Action:
  </code></pre>