摘要:导入: load data infile "c:/1.txt" into table test fields terminated by'|'导出:-- 导出数据为文本文件SELECT ML,DL,ZL,XL,MC,SMINTO OUTFILE 'C:\DM_HY_EXPORT.TXT'FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY ''''LINES TERMINATED BY '\n'FROM DM_HY;
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摘要:update table1 inner join on table2set table1.col1 = table2.col2UPDATE iptable INNER JOIN city ON city.CityName = myfunction(iptable.CityName)SET iptable.cityno = city.CityNO上面iptable 1k条数据, city 20k条数据 本本上花了13min算好, 主要是myfunction()字符串处理花了好长时间。表中插入一列用来算myfunction()结果会快些, 然join匹配会每次计算。ALTER TABLE ipta
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摘要:http://www.accdb.net/article.asp?id=608http://hi.baidu.com/yeihizhi1/blog/item/455c07d42fcf2ace50da4b31.htmlhttp://www.csharpwin.com/csharpspace/8382r3615.shtmlhttp://developer.51cto.com/art/200909/149097.htmhttp://www.cnntec.com/archiver/showtopic-2973.htmlhttp://iofeng.com/Ublog/ShowBlog.aspx?id=2
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摘要:row_number 函数里面有个partition by可以先分组================SELECT*FROM(SELECTrid=ROW_NUMBER()OVER(PARTITIONBY分组ORDERBY排序DESC),*FROM表名)ASTWHERErid<=10==========SELECT * FROM(SELECT rid = ROW_NUMBER() OVER(PARTITION BY dept ORDER BY [time] DESC), * FROM TestTable) AS T WHERE rid <= 5 ===========with newt
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摘要:int[, ,] array = new int[5, 2, 3]; //定义一个5 * 2 * 3 =30的三维数组(array.Length=30) 多维数组只算一个数组 array[1, 1, 1] = 3; array[1, 1, 2] = 4;。。。array[5, 2, 2] = 8;arrayy[5, 2, 3] = 9;===========数组的数组包括多维数组int[][][] array2 = new int[4][][];//数组的数组int[][] array = new int[][]{new int[]{1,2,4},new int[]{1,2,3...
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