BEGIN SET v_variable_name = value; END; 在声明和赋值变量后,可以在select语句中使用变量。可以使用冒号(:)前缀来引用变量。例如: SELECT column1, column2 FROM table_name WHERE column3 = :v_variable_name; 在上面的示例中,:v_variable_name是引用变量的方式。在执行查询时,Oracle会将变量替换为实际的...
以下是使用变量的示例: 声明变量: DECLARE variable_name datatype; 赋值给变量: SET variable_name = value; 或者 SELECT column_name INTO variable_name FROM table_name WHERE condition; 使用变量: 可以在SQL语句中使用变量,例如: SELECT * FROM table_name WHERE column_name = variable_name; 变量的使用可...
新值 1: select * from tt where id=1 45. ID NAME 46. --- --- 47. 1 a 48. SQL> select * from tt where id=&&a; 49. 原值 1: select * from tt where id=&&a 50. 新值 1: select * from tt where id=1 51. ID NAME 52. --- --- 53. 1 a 54. SQL> define b='a'...
SQL>selectsize_for_estimate, estd_physical_read_factor, estd_physical_reads 2fromv$db_cache_advice
update book set price = '53' where bookname = cur.bookname; end loop; end; 2.在游标FOR循环中直接使用子查询 1 2 3 4 5 begin for emp_record in (select ename,sal from emp) loop dbms_output.put_line(emp_record.ename); end loop; end; 三、使用游标更新或删除数据 要通过游标更新或删...
SELECT companyid INTO COMPID from app where appid='90' and rownum=1; 为什么这不能工作? 请您参考如下方法: SELECT INTO DECLARE the_variable NUMBER; BEGIN SELECT my_column INTO the_variable FROM my_table; END; 确保查询仅返回一行: By default, a SELECT INTO statement must return only one row...
set verify off;--是否显示替代变量被替代前后的语句,默认开启 set verify on/off 当在sqlplus中运行的sql语句中有替代变量(以&或&&打头)的时候, set verify(或ver) on/off可以设置是否显示替代变量被替代前后的语句。 如: SQL> set ver on; SQL> select * from dual where 1=&var; ...
setline300pages999coluserhostfora30colos_usernamefora10colusernamefora8colaction_namefora8colsql_textfora80colownerfora8colobj_namefora20colcurrent_userfora12altersessionsetnls_date_format='yyyy-mm-dd hh24:mi:ss';selectos_username,username,userhost,timestamp,owner,obj_name,sql_text,current_userfro...
INSERT INTO PERSONS VALUES(4,'doris'); UPDATE PERSONS SET name = 'zhangsan-update' WHERE ID =1; DELETE PERSONS WHERE ID =2; 在Doris 中进行验证,可以确认增量数据已经成功同步。 mysql> select * from PERSONS; +---+---+ | ID | NAME | +---+---+ | 1 | zhangsan-update | | 4 |...
pragma raise return select update while with <an identifier> <a double-quoted delimited-identifier> <a bind variable> << close current delete fetch lock insert open rollback savepoint set sql execute commit forall merge pipe 行:6 文本: select seq_translate.nextval into:new.TranslateNO from ...