Mysql查询在mysql工作台中运行良好，但在C＃编码中运行不正常 [英] Mysql query is running fine in mysql workbench but not in C# coding

问题描述

mysql query is running fine in mysql workbench but not in c# coding

我是什么尝试过：

What I have tried:

select unitstat.unitgroup,unitstat.tagno, od.status, unitstat.totalcount as DriftCount, unitstat.implication, unitstat.operparam
                           from (
                          select om.unitcode, concat(ifnull(om.unitgroup, ''),'(',ifnull(om.shortunitdesc, ''),')') as unitgroup,oh.tagno, count(*) totalcount, oc.implication,oc.operparam
                           from oehistory oh, oeunitmaster om, oeconfig oc
                           where om.unitcode = oh.unitcode and oh.unitcode=oc.unitcode and oh.tagno=oc.tagno
                           and timestamp between str_to_date ('" + txtFromDate.Text + "', '%d-%b-%y') and str_to_date ('" + txtToDate.Text + "', '%d-%b-%y')";
            strDetails += @" group by om.unitgroup, om.unitcode, om.unitname,om.shortunitdesc, oh.tagno,oc.implication, oc.operparam
                             order by om.unitgroup, om.unitname, oh.tagno
                             ) unitstat, oedata od
                            where od.unitcode = unitstat.unitcode
                            and od.tagno = unitstat.tagno and unitstat.totalcount > 2
                            order by od.status

推荐答案

不要这样做！永远不要连接字符串来构建SQL命令。它让您对意外或故意的SQL注入攻击持开放态度，这可能会破坏您的整个数据库。总是使用参数化查询。



连接字符串时会导致问题，因为SQL会收到如下命令：

Don't do it like that! Never concatenate strings to build a SQL command. It leaves you wide open to accidental or deliberate SQL Injection attack which can destroy your entire database. Always use Parameterized queries instead.

When you concatenate strings, you cause problems because SQL receives commands like:

SELECT * FROM MyTable WHERE StreetAddress = 'Baker's Wood'

就SQL而言，用户添加的引号会终止字符串，并且您会遇到问题。但情况可能更糟。如果我来并改为输入：x'; DROP TABLE MyTable; - 然后SQL收到一个非常不同的命令：

The quote the user added terminates the string as far as SQL is concerned and you get problems. But it could be worse. If I come along and type this instead: "x';DROP TABLE MyTable;--" Then SQL receives a very different command:

SELECT * FROM MyTable WHERE StreetAddress = 'x';DROP TABLE MyTable;--'

哪个SQL看作三个单独的命令：

Which SQL sees as three separate commands:

SELECT * FROM MyTable WHERE StreetAddress = 'x';

完全有效的SELECT

A perfectly valid SELECT

DROP TABLE MyTable;

完全有效的删除表格通讯和

A perfectly valid "delete the table" command

--'

其他一切都是评论。

所以它确实：选择任何匹配的行，从数据库中删除表，并忽略其他任何内容。



所以总是使用参数化查询！或者准备好经常从备份中恢复数据库。你定期做备份，不是吗？

And everything else is a comment.
So it does: selects any matching rows, deletes the table from the DB, and ignores anything else.

So ALWAYS use parameterized queries! Or be prepared to restore your DB from backup frequently. You do take backups regularly, don't you?

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