{"type":"doc","content":[{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"背景介紹"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"筆者在工作中曾遇到SyBase數據庫遷移至MySQL時的一個問題：使用bcp將SyBase中的數據導出爲csv文件時，datetime數據類型默認導出格式與MySQL不兼容。Sybase默認的datetime類型格式爲Mmm dd yyyy hh:nn:ss:sssAA，示例如下："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"text"},"content":[{"type":"text","text":"Dec 24 2017 12:00:00:000PM\n"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"而MySQL中datetime類型格式爲yyyy-mm-dd hh:nn:ss，示例如下："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"text"},"content":[{"type":"text","text":"2017-12-24 12:00:00"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"因此直接將csv文件導入MySQL會由於不兼容導致報錯。"}]},{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"解決方式"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"解決此問題的方式不外乎兩種：一是修改導出後的csv文件，令其時間字段的數據格式兼容MySQL；二是修改SyBase數據庫中時間字段的數據格式，使其直接能通過bcp導出兼容MySQL的csv文件。鑑於第一種方法較爲複雜，本文筆者採用第二種方法解決該問題。"}]},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":"1、convert()函數介紹"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"convert()函數是SyBase數據庫中用於數據類型轉換的函數，其使用方式如下："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"text"},"content":[{"type":"text","text":"convert(datatype,expression,[format-style])"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"datatype：必選參數，將要轉換成的數據類型；"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"expression：必選參數，待轉換的字段；"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"format-style：可選參數，轉換時間類型時，決定輸出格式的參數，對應關係見下表："}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"embedcomp","attrs":{"type":"table","data":{"content":"format-style的值 輸出格式 輸出示例 100 Mmm dd yyyy hh:nnAA Dec 24 2017 12:00PM 101 mm\/dd\/yyyy 12\/24\/2017 102 yyyy.mm.dd 2017.12.24 103 dd\/mm\/yyyy 24\/12\/2017 104 dd.mm.yyyy 24.12.2017 105 dd-mm-yyyy 24-12-2017 106 dd Mmm yyyy 24 Dec 2017 107 Mmm dd,yyyy Dec 24,2017 108 hh:nn:ss 12:00:00 109 Mmm dd yyyy hh:nn:ss:sssAA Dec 24 2017 12:00:00:000PM 110 mm-dd-yyyy 12-24-2017 111 yyyy\/mm\/dd 2017\/12\/24 112 yyyymmdd 20171224"}}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"例如有一個名爲test的表，將該表中一個名爲changetime，類型爲datetime的字段轉換爲varchar類型，可以使用如下SQL語句："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"text"},"content":[{"type":"text","text":"\nselect convert(varchar(100),changetime,111) as dates from test;"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"若該字段僅有一行數據，其值爲Dec 24 2017 12:00:00:000PM，那麼以上SQL輸出的結果爲2017\/12\/24."}]},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":"2、str_replace()函數介紹"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"str_replace()參數用於替換字符串中的部分字符，其使用方式如下："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"text"},"content":[{"type":"text","text":"str_replace(‘string1’,’string2’,’string3’)"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"參數含義："}]},{"type":"bulletedlist","content":[{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"string1：必選參數，原始字符串；"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"string2：必選參數，待轉換的字符；"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"string3：必選參數，需要轉換成的字符；"}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"例如以下SQL："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"text"},"content":[{"type":"text","text":"select str_replace(‘2017\/12\/24’,’\/’,’-’);"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"其輸出結果爲2017-12-24."}]},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":"3、具體方案實施"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"由以上示例可見，若將SyBase中datetime類型字段使用convert()函數轉換爲varchar類型，format-style的值指定爲111，再使用str_replace()函數，將convert()轉換來的字符串中的’\/’轉換爲’-’，即可滿足MySQL中對datetime類型的格式要求（yyyy-mm-dd）；同理，format-style的值指定爲108，即可滿足hh:nn:ss的格式要求。具體的實施方案舉例說明如下："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"1）在SyBase數據庫建立一張臨時表tmp，表結構與待導出數據的表test一致，僅datetime類型字段改爲varchar類型；表結構見以下SQL語句："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"text"},"content":[{"type":"text","text":"create table test(id int,time datetime);\ncreate table tmp(id int,time varchar(100));"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"2）採用如下SQL語句將原始表的數據存入臨時表中："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"text"},"content":[{"type":"text","text":"insert into tmp select id,str_replace(convert(varchar(100),time,111),'\/','-')\n+' '+convert(varchar(100),time,108) from test;"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"3）將臨時表tmp中的數據使用bcp命令導出爲csv文件；"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"4）將csv文件中的數據導入MySQL數據庫對應表中。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"至此，解決了SyBase中datetime類型字段默認導出格式與MySQL不兼容的問題。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"作者介紹"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"農行研發中心“數風雲”團隊，"},{"type":"text","text":"一支朝氣蓬勃、快速成長的技術團隊，始終致力於農行大數據、數據庫和雲計算等領域的應用實踐與技術創新，探索數據賦能，勇攀數據雲巔，爲企業數字化轉型和金融科技發展不斷貢獻力量。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"本文轉載自：dbaplus社羣（ID：dbaplus）"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"原文鏈接："},{"type":"link","attrs":{"href":"https:\/\/mp.weixin.qq.com\/s\/HsoFd9vtWTCQYElcRvdT8Q","title":"xxx","type":null},"content":[{"type":"text","text":"銀行數據庫遷移至MySQL，竟被時間字段這玩意耍了……"}]}]}]} 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