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PostgreSQL 和Oracle 都提供了 row_number() over() 這樣的語句來進行對應的字段排名， 很是方便。 MySQL卻沒有提供這樣的語法。
Table "ytt.t1" Column | Type | Modifiers --------+-----------------------+----------- i_name | character varying(10) | not null rank | integer | not null
t_girl=# select * from t1 order by i_name; i_name | rank ---------+------ Charlie | 12 Charlie | 12 Charlie | 13 Charlie | 10 Charlie | 11 Lily | 6 Lily | 7 Lily | 7 Lily | 6 Lily | 5 Lily | 7 Lily | 4 Lucy | 1 Lucy | 2 Lucy | 2 Ytt | 14 Ytt | 15 Ytt | 14 Ytt | 14 Ytt | 15 (20 rows)
t_girl=# select i_name,rank, row_number() over(partition by i_name order by rank desc) as rank_number from t1; i_name | rank | rank_number ---------+------+------------- Charlie | 13 | 1 Charlie | 12 | 2 Charlie | 12 | 3 Charlie | 11 | 4 Charlie | 10 | 5 Lily | 7 | 1 Lily | 7 | 2 Lily | 7 | 3 Lily | 6 | 4 Lily | 6 | 5 Lily | 5 | 6 Lily | 4 | 7 Lucy | 2 | 1 Lucy | 2 | 2 Lucy | 1 | 3 Ytt | 15 | 1 Ytt | 15 | 2 Ytt | 14 | 3 Ytt | 14 | 4 Ytt | 14 | 5 (20 rows)
t_girl=# select i_name,rank, row_number() over(partition by i_name ) as rank_number from t1; i_name | rank | rank_number ---------+------+------------- Charlie | 12 | 1 Charlie | 12 | 2 Charlie | 13 | 3 Charlie | 10 | 4 Charlie | 11 | 5 Lily | 6 | 1 Lily | 7 | 2 Lily | 7 | 3 Lily | 6 | 4 Lily | 5 | 5 Lily | 7 | 6 Lily | 4 | 7 Lucy | 1 | 1 Lucy | 2 | 2 Lucy | 2 | 3 Ytt | 14 | 1 Ytt | 15 | 2 Ytt | 14 | 3 Ytt | 14 | 4 Ytt | 15 | 5(20 rows)
t_girl=# select i_name,rank, row_number() over() as rank_number from t1; i_name | rank | rank_number ---------+------+------------- Lily | 7 | 1 Lucy | 2 | 2 Ytt | 14 | 3 Ytt | 14 | 4 Charlie | 12 | 5 Charlie | 13 | 6 Lily | 7 | 7 Lily | 4 | 8 Ytt | 14 | 9 Lily | 6 | 10 Lucy | 1 | 11 Lily | 7 | 12 Ytt | 15 | 13 Lily | 6 | 14 Charlie | 11 | 15 Charlie | 12 | 16 Lucy | 2 | 17 Charlie | 10 | 18 Lily | 5 | 19 Ytt | 15 | 20(20 rows)
DELIMITER $$ USE `t_girl`$$ DROP PROCEDURE IF EXISTS `sp_rownumber`$$ CREATE PROCEDURE `sp_rownumber`( IN f_table_name VARCHAR(64), IN f_column_partitionby VARCHAR(64), IN f_column_orderby VARCHAR(64), IN f_is_asc CHAR(4) ) BEGIN -- Created by ytt at 2014/1/10 -- Do a row_number() over() DECLARE i INT; -- Create a temporary table to save result. DROP TABLE IF EXISTS tmp_rownum; SET @stmt = CONCAT('create temporary table tmp_rownum select *,''rownum'' from ',f_table_name,' where 1 = 0'); PREPARE s1 FROM @stmt; EXECUTE s1; SET i = 0; SET @j = 0; SET @v_column_paritionby = ''; -- Check whether parition column is null or not. IF (f_column_partitionby = '' OR f_column_partitionby IS NULL) THEN -- No additional parition column. SET @stmt = CONCAT('insert into tmp_rownum select *,@j:= @j+1 as rownum from ', f_table_name); PREPARE s1 FROM @stmt; EXECUTE s1; ELSE -- Give partition column. SET @stmt = CONCAT('select count(*) from (select count(*) from ',f_table_name,' group by ', f_column_partitionby,') as a into @cnt'); PREPARE s1 FROM @stmt; EXECUTE s1; WHILE i < @cnt DO -- Get the partition value one by one. SET @stmt = CONCAT('select ',f_column_partitionby,' from ',f_table_name,' group by ',f_column_partitionby,' limit ',i,',1 into @v_column_partitionby'); PREPARE s1 FROM @stmt; EXECUTE s1; -- Check whether sort is needed. IF f_column_orderby = '' OR f_column_orderby IS NULL THEN SET @stmt = CONCAT('insert into tmp_rownum select *,@j:= @j+1 as rownum from ', f_table_name,' where ',f_column_partitionby,' = ''',@v_column_partitionby,''''); ELSE SET @stmt = CONCAT('insert into tmp_rownum select *,@j:= @j+1 as rownum from ', f_table_name,' where ',f_column_partitionby,' = ''',@v_column_partitionby,''' order by ',f_column_orderby,' ',f_is_asc); END IF; SET @j = 0; PREPARE s1 FROM @stmt; EXECUTE s1; SET i = i + 1; END WHILE; END IF; -- Reset all session variables. SET @j = NULL; SET @v_column_paritionby = NULL; SET @cnt = NULL; SELECT * FROM tmp_rownum; END$$ DELIMITER ;
CALL sp_rownumber('t1','i_name','rank','desc');query resulti_name rank rownumCharlie 13 1Charlie 12 2Charlie 12 3Charlie 11 4Charlie 10 5Lily 7 1Lily 7 2Lily 7 3Lily 6 4Lily 6 5Lily 5 6Lily 4 7Lucy 2 1Lucy 2 2Lucy 1 3Ytt 15 1Ytt 15 2Ytt 14 3Ytt 14 4Ytt 14 5第二種，
CALL sp_rownumber('t1','i_name',NULL,NULL);query resulti_name rank rownumCharlie 12 1Charlie 13 2Charlie 11 3Charlie 12 4Charlie 10 5Lily 7 1Lily 7 2Lily 4 3Lily 6 4Lily 7 5Lily 6 6Lily 5 7Lucy 2 1Lucy 1 2Lucy 2 3Ytt 14 1Ytt 14 2Ytt 14 3Ytt 15 4Ytt 15 5第三種，
CALL sp_rownumber('t1',NULL,NULL,NULL);query resulti_name rank rownumLily 7 1Lucy 2 2Ytt 14 3Ytt 14 4Charlie 12 5Charlie 13 6Lily 7 7Lily 4 8Ytt 14 9Lily 6 10Lucy 1 11Lily 7 12Ytt 15 13Lily 6 14Charlie 11 15Charlie 12 16Lucy 2 17Charlie 10 18Lily 5 19Ytt 15 20 bitsCN.com
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