delete-drop语句生成的存储过程

问题：

       开发时有时候需要对很多表进行操作。

       例如：清空(删除)所有(某些)表，删除所有表某时间点之后导入的数据(类似于回滚)

解决方式：

　　对选定的表集合执行相同的查询条件(可为空)，如果这个执行结果大于阈值，则使用相同的条件组建delete语句。

delete_drop_sql生成器用法：
delete_drop_sql_generator
(var_where                           [where条件，可以为空,例如：" where LEFT(CREATE_time,19)>"2021-08-04""]
,var_include_tbl_list             [要包含的表名列表,优先于var_exclude_tbl_list,例如："tbl_name1,tbl_name2"]
,var_exclude_tbl_list            [要排除的表名列表,仅在var_include_tbl_list为空时生效,例如："tbl_name1,tbl_name2"]
,var_greater_than_value      [符合where条件要过滤的值,count(*)>=0 ]
)

  1  -- -- powered by wanglifeng https://www.cnblogs.com/wanglifeng717
  2 DROP PROCEDURE IF EXISTS delete_drop_sql_generator;
  3 DELIMITER %%
  4  CREATE PROCEDURE delete_drop_sql_generator(var_where VARCHAR(2048),var_include_tbl_list VARCHAR(2048),var_exclude_tbl_list VARCHAR(2048),var_greater_than_value VARCHAR(100)) 
  5 label:BEGIN
  6 
  7 
  8 
 15 DROP TABLE if exists temp_filter_table;
 16 DROP TABLE if exists temp_var_query_table;
 17 CREATE table temp_var_query_table(tbl_name VARCHAR(512));
 18 
 19 
 20 --   ----------配置项目-----------
 21  -- -- powered by wanglifeng Https://www.cnblogs.com/wanglifeng717
 22 
 23 SET @var_where = var_where;
 24 -- "LEFT(create_time,19)>"2021-08-04"";-- 格式：2021-08-11 16:32:37.872
 25 -- select @var_where;
 26 
 27 -- 如果含有include，则已include为准。
 28 if(var_include_tbl_list IS NULL  OR var_include_tbl_list="include_tbl_list" OR var_include_tbl_list="" OR var_include_tbl_list=" " OR var_include_tbl_list="  ") then 
 29     if(var_exclude_tbl_list IS NULL  OR var_exclude_tbl_list="exclude_tbl_list" OR var_exclude_tbl_list="" OR var_exclude_tbl_list=" " OR var_exclude_tbl_list="  ") then 
 30         -- 如果包含和不含字段都是为空，将库中所有的表加入进去。
 31         INSERT INTO temp_var_query_table SELECT t.table_name FROM infORMation_schema.tables t WHERE table_schema=DATABASE() AND t.TABLE_NAME !="temp_var_query_table";
 32     else
 33        -- 如果include为空，但是exclude不为空
 34         SET @exec_sql = CONCAT_WS("","INSERT INTO temp_var_query_table SELECT t.table_name FROM information_schema.tables t WHERE table_schema=DATABASE() AND t.TABLE_NAME not in ("", REPLACE(var_exclude_tbl_list, ",",CONCAT_WS("","","")),"")"); 
 35         PREPARE stmt  FROM @exec_sql;
 36         EXECUTE stmt;
 37         DEALLOCATE PREPARE stmt;
 38     END if;
 39 ELSE
 40     -- 插入静态字段
 41      SET @exec_sql = CONCAT_WS("","INSERT INTO temp_var_query_table SELECT t.table_name FROM information_schema.tables t WHERE table_schema=DATABASE() AND t.TABLE_NAME  in ("", REPLACE(var_include_tbl_list, ",",CONCAT_WS("","","")),"")"); 
 42     PREPARE stmt  FROM @exec_sql;
 43     EXECUTE stmt;
 44     DEALLOCATE PREPARE stmt;
 45 END if;
 46 
 47 -- select @exec_sql;    
 48 
 49 -- 自定义查找，如果自定义查找，请注释掉上面默认的全库查找
 50 
 51 -- INSERT INTO temp_query_table VALUES ("tbl_act_class"), ("tbl_act_info");
 52 
 53 
 54 
 55 
 56  -- -- powered by wanglifeng https://www.cnblogs.com/wanglifeng717
 57 
 58 
 59 
 60 SET  group_concat_max_len = 4294967295;
 61 
 62 -- select count(*) as "条数","tbl_cbm_app_entrance" as "表名","select count(*) from tbl_cbm_app_entrance   where LEFT(CREATE_time,19)>"2021-08-04"" as "执行的脚本" from tbl_cbm_app_entrance  where LEFT(CREATE_time,19)>"2021-08-04"
 63 SET @query_code="
 64 select (@row_id:=@row_id+1) as "序号", count(*) as "num","@tbl_name" as "tbl_name","select count(*) from @tbl_name  @var_where ;" as "执行的脚本" from @tbl_name, (select @row_id:=0 ) t @var_where 
 65 ";
 66 SELECT REPLACE(@query_code,"@var_where",@var_where) INTO @query_code;
 67 
 68 SELECT GROUP_CONCAT(
 69     t.temp SEPARATOR "
 uNIOn all 
")  INTO @var_query_sql
 70 FROM 
 71 (
 72     SELECT 
 73         REPLACE(@query_code,"@tbl_name",t.TABLE_NAME) as temp
 74     FROM information_schema.tables t
 75     WHERE table_schema=DATABASE() AND t.table_name IN( SELECT * FROM temp_var_query_table WHERE tbl_name NOT IN("temp_var_query_table"))
 76  ) t;
 77 
 78 -- select @var_query_sql;
 79 
 80 SET @exe_sql = @var_query_sql;
 81 PREPARE stmt FROM @exe_sql;
 82 EXECUTE stmt;
 83 DEALLOCATE PREPARE stmt;
 84 
 85 
 86 -- 组成建表语句
 87 
 94 
 95 DROP TABLE if exists temp_filter_table;
 96 SET @exe_sql = CONCAT_WS("","create table temp_filter_table as select t.tbl_name from (",@var_query_sql,") t where t.num>=",var_greater_than_value);
 97 
 98 PREPARE stmt FROM @exe_sql;
 99 EXECUTE stmt;
100 DEALLOCATE PREPARE stmt;
101 
102 -- select @exe_sql;
103 
104 
105 
106 SELECT CONCAT(
107                 "SET FOREIGN_KEY_CHECKS = 0;",
108                 "
",
109                  GROUP_CONCAT(
110                                      CONCAT("drop table "," ",tbl_name,"; ") 
111                                     SEPARATOR "
"
112                                ),
113                  "
",
114                  "SET FOREIGN_KEY_CHECKS = 1;"
115                 )  INTO @drop_sql_code
116 FROM temp_filter_table;
117 
118 SELECT CONCAT(
119                 "SET FOREIGN_KEY_CHECKS = 0;",
120                 "
",
121                  GROUP_CONCAT(
122                                      CONCAT_WS("","delete from ",tbl_name," ",@var_where,";") 
123                                     SEPARATOR "
"
124                                ),
125                  "
",
126                  "SET FOREIGN_KEY_CHECKS = 1;"
127                 ) INTO @delete_sql_code
128 FROM temp_filter_table;
129 
130 SELECT CONCAT(
131                 "SET FOREIGN_KEY_CHECKS = 0;",
132                 "
",
133                  GROUP_CONCAT(
134                                  CONCAT_WS("","select * from ",tbl_name," ",@var_where,";") 
135                                     SEPARATOR "
"
136                                ),
137                  "
",
138                  "SET FOREIGN_KEY_CHECKS = 1;"
139                 ) INTO @select_sql_code
140 FROM temp_filter_table;
141 
142 SELECT "代码","作用" LIMIT 0
143 UNION ALL
144 SELECT  @select_sql_code ,"查询语句"
145 UNION ALL
146 SELECT  @delete_sql_code,"删除语句"
147 UNION ALL 
148 SELECT  @drop_sql_code ,"drop表语句";
149 
150  DROP TABLE if exists temp_filter_table;
151  DROP TABLE if exists temp_var_query_table;
152 END %%
153 DELIMITER ;
154 
155 -- SELECT * from temp_var_query_table;
156 
157 -- CALL delete_drop_sql_generator(" where LEFT(CREATE_time,19)>"2021-08-04"","","","0");

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