Oracle ALTER, DROP, RENAME, ent

1. SQL 명령어
   1. DQL(Data Query Language)
      1. SELECT
   
   
   2. DML(Data Manipulation Language)
      1. INSERT
      2. UPDATE
      3. DELETE
      
      
   3. DDL(Data Definition Language)
      1. CREATE
      
      
      2. ALTER
         1. ALTER TABLE table1  ADD  col1  int;
         2. ALTER TABLE table1  DROP  COLUMN  col1;
         3. ALTER TABLE table1  RENAME COLUMN  col1  TO  col2;     <– 이름 변경
         4. ALTER TABLE table1  MODIFY  col1  varchar(20); <– 자료형 변경
            1. <– 해당 컬럼에 입력정보가 있으면 느리거나, 안되는 경우 발생
      
      
      3. DROP :
         1. DROP TABLE table1
      4. RENAME :
         1. RENAME table1 TO table2
      
      
      5. TRUNCATE :
         1. TRUNCATE TABLE table1;
   
   
   4. TCL(Transaction Control Language)
      1. COMMIT
      2. ROLLBACK
      3. SAVEPOINT
   
   
   5. DCL(Data Control Language)
   6. GRANT
      1. GRANT create session TO user1;
   
   
   7. REVOKE
      1. REVOKE create session FROM user1;
   8.  
2.