oracle数据库高级应用之《自动生成指定表的insert，update，delete语句》

/*
* 多条记录连接成一条
* tableName 表名
* type 类型：可以是insert/update/select之一
*/
create or replace function my_concat(tableName varchar2,type varchar2)
return varchar2
is
type typ_cursor is ref cursor;
v_cursor typ_cursor;
v_temp varchar2(30);
v_result varchar2(4000):= '';
v_sql varchar2(200);
begin
v_sql := 'select COLUMN_NAME from user_tab_columns where table_name = ''' || upper(tableName) || ''' order by COLUMN_ID asc';
open v_cursor for v_sql;
loop
fetch v_cursor into v_temp;
exit when v_cursor%notfound;
if type = 'select' or type = 'insert' then
v_result := v_result ||',' || v_temp;
elsif type = 'update' then
v_result := v_result ||',' || v_temp || ' = ?';
elsif type = 'javabean' then
v_result := v_result ||',bean.get' || upper(substr(v_temp,1,1)) || lower(substr(v_temp,2)) ||  '()';
end if;
end loop;
return substr(v_result,2);
end;

/*
* 通过表名自动生成insert/update/select/javabean get方法语句
* tableName 表名
* type 类型：可以是insert/update/select之一
*/
create or replace procedure autoGenerateSQL(
tableName varchar2,
type varchar2,
out_result out varchar2
)
is
sql_insert varchar2(2000);
sql_update varchar2(2000);
sql_select varchar2(2000);
javabean_str varchar2(2000);
field_num integer;        --字段个数
type_info varchar2(20);   --参数类型判断信息
begin

sql_insert := 'insert into ' || upper(tableName) || '(' || my_concat(tableName,type) || ') values (';
sql_update := 'update ' || upper(tableName) || ' set ';
sql_select := 'select ';
javabean_str := '';
type_info := '';

select count(*) into field_num from user_tab_columns where table_name=upper(tableName);
select decode(type,'insert',type,'update',type,'select',type,'javabean',type,'error') into type_info from dual;

if field_num = 0 then             -- 表不存在时
out_result := '表不存在！请重新输入!';
elsif type_info = 'error' then    --type参数错误时
out_result := 'type参数错误：类型只能是insert、update、select、javabean之一';
elsif field_num > 0 then
if type = 'insert' then         --生成insert 语句
for i in 1..field_num
loop
sql_insert := sql_insert || '?';
if i < field_num then
sql_insert := sql_insert || ',';
end if;
end loop;
sql_insert := sql_insert || ')';
out_result := sql_insert;
elsif type = 'update' then      --生成update 语句
sql_update := sql_update || my_concat(tableName,type);
out_result := sql_update;
elsif type = 'select' then      --生成select 语句
sql_select := sql_select || my_concat(tableName,type) || ' from ' || upper(tableName) || ' a';
out_result := sql_select;
elsif type = 'javabean' then    --生成javabean的get方法
javabean_str := my_concat(tableName,type);
out_result := javabean_str;
end if;
end if;

end autoGenerateSQL;

declare out_result varchar2(512);
begin
autoGenerateSQL('tf_Employee2','insert', out_result);
dbms_output.put_line(out_result);
end;