SQL 中常用的关键字及作用

SQL 中常用的关键字及作用

 

sql 常用的关键词

模块                                                           关键词                                                              功能

数据定义                                             create       table                                            创建表                                                              create       view                                             创建视图                                                              create       index                                            创建索引                                                              create      procedure                                    创建存储过程                                                              create      trigger                                           创建触发器                                                              drop          table                                             删除表                                                              alter            table                                            修改表                                                              drop          view                                              删除视图                                                              drop           index                                            删除索引                                                              drop           procedure                                   删除存储过程                                                              drop              trigger                                        删除触发器

数据操作                                                     select                                                                                                                             insert                                                                       delete                                                                        update

数据控制                                                      grant                                                       授予用户访问权限                                                                       revoke                                                    解除用户权限                                                                      deny                                                        拒绝用户访问

事务控制                                                      commit                                                    提交事务                                                                       rollback                                                    回滚当前事务                                                                    set     transaction                                       定义当前事务数据访问特征

程序化 sql                                              declare                                                      为查询设置游标                                                                   explain                                                      为查询描述数据访问计划                                                                   open                                                           检索查询结果打开一个游标                                                                   fetch                                                           检查一行查询结果                                                                  close                                                           关闭游标                                                                    prepare                                                      为动态执行准备sql                                                                   execute                                                        动态执行sql                                                                   describe                                                     描述准备好的查询