oracle 表管理

主键自增策略

参考:
Oracle实现主键自增有4种方式
Oracle 自增长主键 三种方式
Oracle中sequence（序列）详解
mybatis+oracle数据库新增数据，返回主键，主键回显

oracle 数据类型

Oracle中的数据类型详解

创建表

create table sys_dict_type(
id number(20) primary key,
name varchar2(100) ,
type varchar2(100) ,
group_code varchar2(100) ,
status char(1) 
);
comment on table sys_dict_type is '系统字典类型表';
comment on column sys_dict_type.name is '字典名称';
comment on column sys_dict_type.type is '字典类型编码';
comment on column sys_dict_type.group_code is '字典分组 (system:系统字典)';
comment on column sys_dict_type.status is '状态 (0:正常 1:停用)';

查询表结构

参考: Oracle中查询表结构的六种方法

desc

SQL> desc sys_dict_type;
Name       Type          Nullable Default Comments           
---------- ------------- -------- ------- ------------------ 
ID         NUMBER(20)                                        
NAME       VARCHAR2(100) Y                字典名称           
TYPE       VARCHAR2(100) Y                字典类型编码       
GROUP_CODE VARCHAR2(100) Y                字典分组 (system:系统字典) 
STATUS     CHAR(1)       Y                状态 (0:正常 1:停用) SQL> 

user_tab_columns

表名要大写

SQL> select * from user_tab_columns where table_name = 'SYS_DICT_TYPE';TABLE_NAME                     COLUMN_NAME                    DATA_TYPE                                                                        DATA_TYPE_MOD DATA_TYPE_OWNER                DATA_LENGTH DATA_PRECISION DATA_SCALE NULLABLE  COLUMN_ID DEFAULT_LENGTH DATA_DEFAULT                                                                     NUM_DISTINCT LOW_VALUE                                                        HIGH_VALUE                                                          DENSITY  NUM_NULLS NUM_BUCKETS LAST_ANALYZED SAMPLE_SIZE CHARACTER_SET_NAME                           CHAR_COL_DECL_LENGTH GLOBAL_STATS USER_STATS AVG_COL_LEN CHAR_LENGTH CHAR_USED V80_FMT_IMAGE DATA_UPGRADED HISTOGRAM
------------------------------ ------------------------------ -------------------------------------------------------------------------------- ------------- ------------------------------ ----------- -------------- ---------- -------- ---------- -------------- -------------------------------------------------------------------------------- ------------ ---------------------------------------------------------------- ---------------------------------------------------------------- ---------- ---------- ----------- ------------- ----------- -------------------------------------------- -------------------- ------------ ---------- ----------- ----------- --------- ------------- ------------- ---------------
SYS_DICT_TYPE                  ID                             NUMBER                                                                                                                                 22             20          0 N                 1                                                                                                                                                                                                                                                                                                                                                                              NO           NO                               0           NO            YES           NONE
SYS_DICT_TYPE                  NAME                           VARCHAR2                                                                                                                              100                           Y                 2                                                                                                                                                                                                                                                                                                            CHAR_CS                                                       100 NO           NO                             100 B         NO            YES           NONE
SYS_DICT_TYPE                  TYPE                           VARCHAR2                                                                                                                              100                           Y                 3                                                                                                                                                                                                                                                                                                            CHAR_CS                                                       100 NO           NO                             100 B         NO            YES           NONE
SYS_DICT_TYPE                  GROUP_CODE                     VARCHAR2                                                                                                                              100                           Y                 4                                                                                                                                                                                                                                                                                                            CHAR_CS                                                       100 NO           NO                             100 B         NO            YES           NONE
SYS_DICT_TYPE                  STATUS                         CHAR                                                                                                                                    1                           Y                 5                                                                                                                                                                                                                                                                                                            CHAR_CS                                                         1 NO           NO                               1 B         NO            YES           NONESQL> 

all_col_columns

表名要大写

select ts.table_name, ts.column_name, ts.data_type, ts.data_length, tc.comments
from   all_tab_columns ts
left   join all_col_comments tc
on     ts.table_name = tc.table_nameand ts.column_name = tc.column_name
where  ts.table_name = 'SYS_DICT_TYPE';

查询表注释

select * from user_tab_comments  where table_name = 'SYS_DICT_TYPE';

修改表

ALTERR TABLE tablename ADD (columnname datatype) ;
ALTERR TABLE tablename MODIFY (columnname datatype) ;
ALTERR TABLE tablename DROP (columnname datatype) ;
rename 表名 to 新表名;