oracle开发学习篇之集合函数
集合函数; declare type list_nested is table of varchar2(100) not null; v_all list_nested := list_nested(‘changan‘,‘hubei‘,‘shanghai‘,‘beijing‘,‘Android‘,‘Java-Android‘); BEGIN v_all.delete(1); for x in v_all.first .. v_all.last loop dbms_output.put_line(v_all(x)); end loop; --dbms_output.put_line(‘list leng:‘ || v_all.count ); end; / declare type list_nested is table of varchar2(100) not null; v_all list_nested := list_nested(‘changan‘,‘hubei‘,‘shanghai‘,‘beijing‘,‘Android‘,‘Java-Android‘); BEGIN v_all.delete(1,3); --指定删除索引范围的数据; for x in v_all.first .. v_all.last loop dbms_output.put_line(v_all(x)); end loop; dbms_output.put_line(‘list leng:‘ || v_all.count ); end; / declare type list_nested is table of varchar2(100) not null; v_all list_nested := list_nested(‘changan‘,‘hubei‘,‘shanghai‘,‘beijing‘,‘Android‘,‘Java-Android‘); BEGIN if v_all.EXISTS(1) then dbms_output.put_line(‘索引为1的数据存在‘); end if; if not v_all.EXISTS(10) then dbms_output.put_line(‘索引为10的数据不存在‘); end if; end; / declare type list_nested is table of varchar2(100) not null; v_all list_nested := list_nested(‘FireFox‘,‘firefox.com‘,‘www.firefox.com‘); begin dbms_output.put_line(‘原始长度‘ || v_all.count); v_all.extend(2); dbms_output.put_line(‘扩充之后长度‘ || v_all.count); v_all(4) := ‘www.google.com‘; v_all(5) := ‘Google.com‘; for x in v_all.first .. v_all.last loop dbms_output.put_line(v_all(x)); end loop; end; / 范例 扩充集合长度,并使用已有内容填充 declare type list_nested is table of varchar2(100) not null; v_all list_nested := list_nested(‘FireFox‘,‘firefox.com‘,‘www.firefox.com‘); begin dbms_output.put_line(‘原始长度‘ || v_all.count); v_all.extend(2 , 3); dbms_output.put_line(‘扩充之后长度‘ || v_all.count); for x in v_all.first .. v_all.last loop dbms_output.put_line(v_all(x)); end loop; end; / 范例 集合函数count limit declare type list_varray is varray(20) of varchar2(100); v_info list_varray := list_varray(‘firefox.com‘,‘www.firefox.com‘,‘www.oracle.com‘); begin dbms_output.put_line(‘数组集合的最大长度‘ || v_info.limit); dbms_output.put_line(‘数组集合的数据量‘ || v_info.count); end; / declare type info_index is table of varchar2(20) index by PLS_INTEGER; v_info info_index; v_foot number; begin v_info(1) := ‘FireFox‘; v_info(10) := ‘Java‘; v_info(-10) := ‘oracle‘; v_info(-20) := ‘EJB‘; v_info(30) := ‘Android‘; v_foot := v_info.first; while (v_info.exists(v_foot)) loop dbms_output.put_line(‘v_info (‘ || v_foot ||‘) = ‘ || v_info(v_foot); v_foot := v_info.next(v_foot) ; end loop; end; / declare type info_index is table of varchar2(20) index by PLS_INTEGER; v_info info_index; v_foot number; begin v_info(1) := ‘FireFox‘; v_info(10) := ‘Java‘; v_info(-10) := ‘oracle‘; v_info(-20) := ‘EJB‘; v_info(30) := ‘Android‘; DBMS_OUTPUT.put_line(‘索引为10的下一个索引是:‘ || v_info.next(10)); dbms_output.put_line(‘索引为-10的上一个索引是:‘ || v_info.prior(-10)); end; / declare type list_varray is varray(8) of varchar2(50); v_info list_varray := list_varray(‘FireFox‘,‘www.FireFox‘,‘www.Google.com‘,‘EJB‘); begin dbms_output.put_line(); for x in v_info.first .. v_info.last loop dbms_output.put_line(v_info(x)); end loop; end; / declare type list_varray is varray(8) of varchar2(100); v_info list_varray := list_varray(‘FireFox‘,‘www.firefox.com‘,‘oracle‘,‘oracle_username‘); begin dbms_output.put_line(‘删除集合之前的数量:‘ || v_info.count); v_info.trim; -- 删除一个数据; dbms_output.put_line(‘v_info.trim 删除集合之后的数据量 :‘ || v_info.count); v_info.trim(2); -- 删除2个数据; dbms_output.put_line(‘v_info.trim(2) 删除集合之后的数据量 :‘ || v_info.count); for x in v_info.first .. v_info.last loop dbms_output.put_line(v_info(x)); end loop; end; /
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