时间:2021-07-01 10:21:17 帮助过:45人阅读
数据量很大时,需要对数据表做分表处理,比如按号码取模,日期等分表:TABLE_0_20131001,TABLE_99_20131031 公司为了所谓的可移植性不让使用数据库的分区表特性,就只能自己手工分表了.这样一来分表数量庞大,分表的管理维护是个问题,如变动表结构,批量建表之类的操
数据量很大时,需要对数据表做分表处理, 比如按号码取模,日期等分表: TABLE_0_20131001, TABLE_99_20131031-- exesql_batch declare -- incomming param v_oriSql VARCHAR2(1024):= 'create table TABLE_[N]_[D] as select * from TABLE where 1=2'; -- original sql v_beg NUMBER := 0; -- begin of number v_end NUMBER := 9; -- end of number [beg, end] v_begDate DATE := to_date('20130701', 'YYYYMMDD'); -- begin date v_endDate DATE := to_date('20130731', 'YYYYMMDD'); -- end date, [beg, end] v_dateSw NUMBER := 1; -- date switch 1:day, others:month -- internel var v_dateNum NUMBER := 0; v_numNum NUMBER := 0; v_strDate VARCHAR2(8); v_destSql VARCHAR2(2000); V_DATE VARCHAR2(3) := '[D]'; V_NUM VARCHAR2(3) := '[N]'; begin if INSTR(v_oriSql, V_DATE) <> 0 then if v_dateSw = 1 then v_dateNum := trunc(v_endDate, 'DD') - trunc(v_begDate, 'DD'); else v_dateNum := MONTHS_BETWEEN(trunc(v_endDate, 'MM'), trunc(v_begDate, 'MM')); end if; end if; if INSTR(v_oriSql, V_NUM) <> 0 then v_numNum := v_end - v_beg; end if; -- loop for i in 0 .. v_numNum loop for j in 0 .. v_dateNum loop if v_dateSw = 1 then v_strDate := to_char(v_begDate + j, 'YYYYMMDD'); else v_strDate := to_char(ADD_MONTHS(v_begDate, j), 'YYYYMM'); end if; v_destSql := REPLACE(v_oriSql, V_NUM, v_beg + i); v_destSql := REPLACE(v_destSql, V_DATE, v_strDate); EXECUTE IMMEDIATE v_destSql; end loop; end loop; end;
-- exesql_batch -- 1.procedure define delimiter $$ DROP PROCEDURE IF EXISTS exesql_batch$$ CREATE PROCEDURE exesql_batch( IN v_oriSql VARCHAR(1024), -- original sql IN v_beg INT, -- begin of number IN v_end INT, -- end of number [beg, end] IN v_begDate DATE, -- begin date IN v_endDate DATE, -- end date, [beg, end] IN v_dateSw INT -- date switch 1:day, others:month ) BEGIN DECLARE v_dateNum INT DEFAULT 0; DECLARE v_numNum INT DEFAULT 0; DECLARE v_strDate VARCHAR(8); DECLARE i INT; DECLARE j INT; DECLARE V_DATE VARCHAR(3) DEFAULT '[D]'; DECLARE V_NUM VARCHAR(3) DEFAULT '[N]'; if INSTR(v_oriSql, V_DATE) <> 0 then if v_dateSw = 1 then SET v_dateNum = DATEDIFF(v_endDate, v_begDate); else SET v_dateNum = (YEAR(v_endDate)-YEAR(v_begDate))*12 + (MONTH(v_endDate)-MONTH(v_begDate)); end if; end if; if INSTR(v_oriSql, V_NUM) <> 0 then SET v_numNum = v_end - v_beg; end if; -- loop SET i=0; while i<=v_numNum do SET j=0; while j<=v_dateNum do if v_dateSw = 1 then SET v_strDate = DATE_FORMAT(DATE_ADD(v_begDate, INTERVAL j DAY), '%Y%m%d'); else SET v_strDate = DATE_FORMAT(DATE_ADD(v_begDate, INTERVAL j MONTH), '%Y%m'); end if; SET @v_destSql = REPLACE(v_oriSql, V_NUM, v_beg+i); SET @v_destSql = REPLACE(@v_destSql, V_DATE, v_strDate); PREPARE s1 FROM @v_destSql; EXECUTE s1; DEALLOCATE PREPARE s1; SET j=j+1; end while; SET i=i+1; end while; END$$ delimiter ; -- 2.demo -- crate tables from TABLE_0_20131001 to TABLE_9_20131031 CALL exesql_batch( 'create table TABLE_[N]_[D] like TABLE', -- original sql 0, -- begin of number 9, -- end of number, [beg, end] str_to_date('20131001', '%Y%m%d'), -- begin date str_to_date('20131031', '%Y%m%d'), -- end date, [beg, end] 1 -- date switch 1:day, others:month );