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Categories / Oracle PLSQL Tutorial / Query Select
 

Use rownum to limit the resultset

SQL> describe user_tables;  Name                               Null?    Type  ---------------------------------------------------------  TABLE_NAME                         NOT NULL VARCHAR2(30)  TABLESPACE_NAME                             VARCHAR2(30)  CLUSTER_NAME                                VARCHAR2(30)  IOT_NAME                                    VARCHAR2(30)  STATUS                                      VARCHAR2(8)  PCT_FREE                                    NUMBER  PCT_USED                                    NUMBER  INI_TRANS                                   NUMBER  MAX_TRANS                                   NUMBER  INITIAL_EXTENT                              NUMBER  NEXT_EXTENT                                 NUMBER  MIN_EXTENTS                                 NUMBER  MAX_EXTENTS                                 NUMBER  PCT_INCREASE                                NUMBER  FREELISTS                                   NUMBER  FREELIST_GROUPS                             NUMBER  LOGGING                                     VARCHAR2(3)  BACKED_UP                                   VARCHAR2(1)  NUM_ROWS                                    NUMBER  BLOCKS                                      NUMBER  EMPTY_BLOCKS                                NUMBER  AVG_SPACE                                   NUMBER  CHAIN_CNT                                   NUMBER  AVG_ROW_LEN                                 NUMBER  AVG_SPACE_FREELIST_BLOCKS                   NUMBER  NUM_FREELIST_BLOCKS                         NUMBER  DEGREE                                      VARCHAR2(10)  INSTANCES                                   VARCHAR2(10)  CACHE                                       VARCHAR2(5)  TABLE_LOCK                                  VARCHAR2(8)  SAMPLE_SIZE                                 NUMBER  LAST_ANALYZED                               DATE  PARTITIONED                                 VARCHAR2(3)  IOT_TYPE                                    VARCHAR2(12)  TEMPORARY                                   VARCHAR2(1)  SECONDARY                                   VARCHAR2(1)  NESTED                                      VARCHAR2(3)  BUFFER_POOL                                 VARCHAR2(7)  ROW_MOVEMENT                                VARCHAR2(8)  GLOBAL_STATS                                VARCHAR2(3)  USER_STATS                                  VARCHAR2(3)  DURATION                                    VARCHAR2(15)  SKIP_CORRUPT                                VARCHAR2(8)  MONITORING                                  VARCHAR2(3)  CLUSTER_OWNER                               VARCHAR2(30)  DEPENDENCIES                                VARCHAR2(8)  COMPRESSION                                 VARCHAR2(8)  DROPPED                                     VARCHAR2(3) SQL> SQL> select table_name, tablespace_name   2  from user_tables   3  where rownum < 30   4  order by table_name; TABLE_NAME                     TABLESPACE_NAME ------------------------------ ------------------------------ EMPLOYEE_TAB EMP_DEPT                       SYSTEM PEOPLE                         SYSTEM SESS_EVENT TEMP_ALL_OBJECTS TRANSACTION_TAB 6 rows selected. SQL>