知识大全解析SQL2005中如何使用CLR函数获取行号

Posted 2022-07-15 文件

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　　SQLServer数据导出到excel有很多种方法比如dts ssis 还可以用sql语句调用openrowset 我们这里开拓思路用CLR来生成Excel文件并且会考虑一些方便操作的细节下面我先演示一下我实现的效果先看测试语句

复制代码代码如下: exec BulkCopyToXls select * from testTable d:/test testTable /* 开始导出数据文件 d:/test/testTable xls 共条大小字节文件 d:/test/testTable xls 共条大小字节文件 d:/test/testTable xls 共条大小字节文件 d:/test/testTable xls 共条大小字节文件 d:/test/testTable xls 共条大小字节文件 d:/test/testTable xls 共条大小字节文件 d:/test/testTable xls 共条大小字节文件 d:/test/testTable xls 共条大小字节导出数据完成共条数据耗时 ms */

　　上面的BulkCopyToXls存储过程是自定的CLR存储过程他有四个参数第一个是sql语句用来获取数据集第二个是文件保存的路径第三个是结果集的名字我们用它来给文件命名第四个是限制单个文件可以保存多少条记录小于等于表示最多条前三个参数没有什么特别最后一个参数的设置可以让一个数据集分多个excel文件保存比如传统excel的最大容量是条数据我们这里参数设置为就表示导出达到这个数字之后自动写下一个文件如果你设置了比如那么每导出条就会自动写下一个文件另外每个文件都可以输出字段名作为表头所以单个文件最多容纳条数据用微软公开的biff 格式通过二进制流生成excel 服务器无需安装excel组件而且性能上不会比sql自带的功能差万多条数据 M 用了秒完成下面我们来看下CLR代码通过sql语句获取DataReader 然后分批用biff格式来写xls文件

复制代码代码如下: using System; using System Data; using System Data SqlClient; using System Data SqlTypes; using Microsoft SqlServer Server; public partial class StoredProcedures /// <summary> /// 导出数据 /// </summary> /// <param name=sql></param> /// <param name=savePath></param> /// <param name=tableName></param> /// <param name=maxRecordCount></param> [Microsoft SqlServer Server SqlProcedure ] public static void BulkCopyToXls(SqlString sql SqlString savePath SqlString tableName SqlInt maxRecordCount) if (sql IsNull || savePath IsNull || tableName IsNull) SqlContext Pipe Send(" 输入信息不完整！" ); ushort _maxRecordCount = ushort MaxValue ; if (maxRecordCount IsNull == false && maxRecordCount Value < ushort MaxValue&&maxRecordCount Value> ) _maxRecordCount = (ushort )maxRecordCount Value; ExportXls(sql Value savePath Value tableName Value _maxRecordCount); /// <summary> /// 查询数据生成文件 /// </summary> /// <param name=sql></param> /// <param name=savePath></param> /// <param name=tableName></param> /// <param name=maxRecordCount></param> private static void ExportXls(string sql string savePath string tableName System UInt maxRecordCount) if (System IO Directory Exists(savePath) == false ) System IO Directory CreateDirectory(savePath); using (SqlConnection conn = new SqlConnection ("context connection=true" )) conn Open(); using (SqlCommand mand = conn CreateCommand()) mand CommandText = sql; using (SqlDataReader reader = mand ExecuteReader()) int i = ; int totalCount = ; int tick = System Environment TickCount; SqlContext Pipe Send(" 开始导出数据" ); while (true ) string fileName = string Format(@" / xls" savePath tableName i++); int iExp = Write(reader maxRecordCount fileName); long size = new System IO FileInfo (fileName) Length; totalCount += iExp; SqlContext Pipe Send(string Format(" 文件共条大小字节" fileName iExp size ToString("### ###" ))); if (iExp < maxRecordCount) break ; tick = System Environment TickCount tick; SqlContext Pipe Send(" 导出数据完成" ); SqlContext Pipe Send(" " ); SqlContext Pipe Send(string Format(" 共条数据耗时 ms" totalCount tick)); /// <summary> /// 写单元格 /// </summary> /// <param name=writer></param> /// <param name=obj></param> /// <param name=x></param> /// <param name=y></param> private static void WriteObject(ExcelWriter writer object obj System UInt x System UInt y) string type = obj GetType() Name ToString(); switch (type) case "SqlBoolean" : case "SqlByte" : case "SqlDecimal" : case "SqlDouble" : case "SqlInt " : case "SqlInt " : case "SqlInt " : case "SqlMoney" : case "SqlSingle" : if (obj ToString() ToLower() == "null" ) writer WriteString(x y obj ToString()); else writer WriteNumber(x y Convert ToDouble(obj ToString())); break ; default : writer WriteString(x y obj ToString()); break ; /// <summary> /// 写一批数据到一个excel 文件 /// </summary> /// <param name=reader></param> /// <param name=count></param> /// <param name=fileName></param> /// <returns></returns> private static int Write(SqlDataReader reader System UInt count string fileName) int iExp = count; ExcelWriter writer = new ExcelWriter (fileName); writer BeginWrite(); for (System UInt j = ; j < reader FieldCount; j++) writer WriteString( j reader GetName(j)); for (System UInt i = ; i <= count; i++) if (reader Read() == false ) iExp = i ; break ; for (System UInt j = ; j < reader FieldCount; j++) WriteObject(writer reader GetSqlValue(j) i j); writer EndWrite(); return iExp; /// <summary> /// 写excel 的对象 /// </summary> public class ExcelWriter System IO FileStream _wirter; public ExcelWriter(string strPath) _wirter = new System IO FileStream (strPath System IO FileMode OpenOrCreate); /// <summary> /// 写入short 数组 /// </summary> /// <param name=values></param> private void _writeFile(System UInt [] values) foreach (System UInt v in values) byte [] b = System BitConverter GetBytes(v); _wirter Write(b b Length); /// <summary> /// 写文件头 /// </summary> public void BeginWrite() _writeFile(new System UInt [] x x ); /// <summary> /// 写文件尾 /// </summary> public void EndWrite() _writeFile(new System UInt [] xa ); _wirter Close(); /// <summary> /// 写一个数字到单元格x y /// </summary> /// <param name=x></param> /// <param name=y></param> /// <param name=value></param> public void WriteNumber(System UInt x System UInt y double value) _writeFile(new System UInt [] x x y ); byte [] b = System BitConverter GetBytes(value); _wirter Write(b b Length); /// <summary> /// 写一个字符到单元格x y /// </summary> /// <param name=x></param> /// <param name=y></param> /// <param name=value></param> public void WriteString(System UInt x System UInt y string value) byte [] b = System Text Encoding Default GetBytes(value); _writeFile(new System UInt [] x (System UInt )(b Length + ) x y (System UInt )b Length ); _wirter Write(b b Length); ;

　　把上面代码编译为TestExcel dll copy到服务器目录然后通过如下SQL语句部署存储过程

复制代码代码如下: CREATE ASSEMBLY TestExcelForSQLCLR FROM d:/sqlclr/TestExcel dll WITH PERMISSION_SET = UnSAFE; go CREATE proc dbo BulkCopyToXls ( @sql nvarchar ( max ) @savePath nvarchar ( ) @tableName nvarchar ( ) @bathCount int ) AS EXTERNAL NAME TestExcelForSQLCLR StoredProcedures BulkCopyToXls go cha138/Article/program/MySQL/201311/29542

知识大全 解析SQL2005中如何使用CLR函数获取行号

知识大全解析SQL2005中如何使用CLR函数获取行号