Home Database Mysql Tutorial Oracle使用游标查询指定数据表的所有字段名称组合而成的字符串

Oracle使用游标查询指定数据表的所有字段名称组合而成的字符串

Jun 07, 2016 pm 04:33 PM
oracle cursor

应用场合:参考网上查询数据表的所有字段名代码,使用游标生成指定单个表的所有字段名跟逗号组成的用于select 逗号隔开的字段名

应用场合:参考网上查询数据表的所有字段名代码,,使用游标生成指定单个表的所有字段名跟逗号组成的用于select  逗号隔开的字段名列表 from字符串等场合。

查询结果输出如下:

当前数据表TB_UD_USER的字段列表字符串为
AH,BIRTHPLACE,BM,CELLPHONE,CJGZRQ,DEPARTMENT2,DJJID,GZCX,GZKH,GZSFZH,HJDZ,HYZK,ID,JHRQ,JTZZ,LAFX_LD,LJDZ,LLY,LXDH,NAME,NXDH,POLICENUMBER,RESERVE1,RESERVE10,RESERVE9,SCCP,SEX,SFJH,SFQBY,SFZ,SPJB,YL_22,ZJ,ZW,ZZMM
当前数据表TB_UD_USER查询所有记录语句为
select AH,BIRTHPLACE,BM,CELLPHONE,CJGZRQ,DEPARTMENT2,DJJID,GZCX,GZKH,GZSFZH,HJDZ,HYZK,ID,JHRQ,JTZZ,LAFX_LD,LJDZ,LLY,LXDH,NAME,NXDH,POLICENUMBER,RESERVE1,RESERVE10,RESERVE9,SCCP,SEX,SFJH,SFQBY,SFZ,SPJB,YL_22,ZJ,ZW,ZZMM from TB_UD_USER

详细脚本代码如下:

--Oracle使用游标查询指定数据表的所有字段名称组合而成的字符串

declare
mytablename NVARCHAR2(200):='TB_UD_USER'; --定义要查询的数据表名称变量
mystring NVARCHAR2(1000):=' '; --定义要输出的字段名称列表字符串变量 
selstring VARCHAR2(2000):=' '; --定义要输出的查询语句字符串变量 

cursor mycursor is --定义游标 

select distinct TABLE_COLUMN.*,TABLE_NALLABLE.DATA_TYPE,TABLE_NALLABLE.NULLABLE  from (select distinct utc.table_name  table_name, utc.comments    table_comments, ucc.column_name column_name, ucc.comments    column_comments from user_tab_comments utc, user_col_comments ucc  where utc.table_name = ucc.table_name  and utc.table_name not like '%_B'  and utc.table_name not like '%_Z'  and utc.table_name not like '%1%') TABLE_COLUMN,      (select distinct table_name, column_name, nullable, DATA_TYPE from user_tab_cols  where table_name not like '%_B'  and table_name not like '%_Z'  and table_name not like '%1%') TABLE_NALLABLE  where TABLE_COLUMN.column_name = TABLE_NALLABLE.column_name  and TABLE_COLUMN.TABLE_NAME = TABLE_NALLABLE.table_name  and TABLE_COLUMN.TABLE_NAME=mytablename  order by TABLE_COLUMN.TABLE_NAME,TABLE_COLUMN.column_name;

myrecord mycursor%rowtype;  --定义游标记录类型 
Counter int :=0; 
begin 
open mycursor;  --打开游标 
if mycursor%isopen  then  --判断打开成功 
loop --循环获取记录集   
fetch mycursor into myrecord; --获取游标中的记录       

if mycursor%found then  --游标的found属性判断是否有记录 
begin
  --如果是第一个字段
  if(mystring=' ') then
  mystring:=myrecord.column_name;
  else
  mystring:=mystring||','||myrecord.column_name;
  end if;

end;

else 

begin
 
dbms_output.put_line('当前数据表'||mytablename||'的字段列表字符串为');
dbms_output.put_line(mystring);

selstring:='select '||mystring||' from '||mytablename;

dbms_output.put_line('当前数据表'||mytablename||'查询所有记录语句为');
dbms_output.put_line(selstring);

exit;

end;

end if;
 
end loop; 
else   
dbms_output.put_line('游标没有打开'); 
end if; 

close mycursor;

end;

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