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

 1 /*
 2 * 多条记录连接成一条
 3 * tableName 表名
 4 * type 类型：可以是insert/update/select之一
 5 */
 6 create or replace function my_concat(tableName varchar2,type varchar2)
 7 return varchar2
 8 is
 9  type typ_cursor is ref cursor;
10  v_cursor typ_cursor;
11  v_temp varchar2(30);
12  v_result varchar2(4000):= ‘‘;
13  v_sql varchar2(200);
14 begin
15  v_sql := ‘select COLUMN_NAME from user_tab_columns where table_name = ‘‘‘ || upper(tableName) || ‘‘‘ order by COLUMN_ID asc‘;
16  open v_cursor for v_sql;
17  loop
18     fetch v_cursor into v_temp;
19     exit when v_cursor%notfound;
20     if type = ‘select‘ or type = ‘insert‘ then
21        v_result := v_result ||‘,‘ || v_temp;
22     elsif type = ‘update‘ then
23        v_result := v_result ||‘,‘ || v_temp || ‘ = ?‘;
24     elsif type = ‘javabean‘ then
25        v_result := v_result ||‘,bean.get‘ || upper(substr(v_temp,1,1)) || lower(substr(v_temp,2)) ||  ‘()‘;
26     end if;
27  end loop;
28  return substr(v_result,2);
29 end;
30
31
32 /*
33 * 通过表名自动生成insert/update/select/javabean get方法语句
34 * tableName 表名
35 * type 类型：可以是insert/update/select之一
36 */
37 create or replace procedure autoGenerateSQL(
38 tableName varchar2,
39 type varchar2,
40 out_result out varchar2
41 )
42 is
43   sql_insert varchar2(2000);
44   sql_update varchar2(2000);
45   sql_select varchar2(2000);
46   javabean_str varchar2(2000);
47   field_num integer;        --字段个数
48   type_info varchar2(20);   --参数类型判断信息
49 begin
50
51 sql_insert := ‘insert into ‘ || upper(tableName) || ‘(‘ || my_concat(tableName,type) || ‘) values (‘;
52 sql_update := ‘update ‘ || upper(tableName) || ‘ set ‘;
53 sql_select := ‘select ‘;
54 javabean_str := ‘‘;
55 type_info := ‘‘;
56
57 select count(*) into field_num from user_tab_columns where table_name=upper(tableName);
58 select decode(type,‘insert‘,type,‘update‘,type,‘select‘,type,‘javabean‘,type,‘error‘) into type_info from dual;
59
60 if field_num = 0 then             -- 表不存在时
61    out_result := ‘表不存在！请重新输入!‘;
62 elsif type_info = ‘error‘ then    --type参数错误时
63    out_result := ‘type参数错误：类型只能是insert、update、select、javabean之一‘;
64 elsif field_num > 0 then
65   if type = ‘insert‘ then         --生成insert 语句
66     for i in 1..field_num
67       loop
68          sql_insert := sql_insert || ‘?‘;
69          if i < field_num then
70             sql_insert := sql_insert || ‘,‘;
71          end if;
72       end loop;
73       sql_insert := sql_insert || ‘)‘;
74       out_result := sql_insert;
75   elsif type = ‘update‘ then      --生成update 语句
76       sql_update := sql_update || my_concat(tableName,type);
77       out_result := sql_update;
78   elsif type = ‘select‘ then      --生成select 语句
79       sql_select := sql_select || my_concat(tableName,type) || ‘ from ‘ || upper(tableName) || ‘ a‘;
80       out_result := sql_select;
81   elsif type = ‘javabean‘ then    --生成javabean的get方法
82       javabean_str := my_concat(tableName,type);
83       out_result := javabean_str;
84   end if;
85 end if;
86
87 end autoGenerateSQL;
88
89 declare out_result varchar2(512);
90 begin
91 autoGenerateSQL(‘tf_Employee2‘,‘insert‘, out_result);
92 dbms_output.put_line(out_result);
93 end;