SQL从CSV的条件SELECT [英] SQL Conditional SELECT from CSV

问题描述

我正在尝试使用SQL查询 SELECT * FROM [+ fileName +]; 从CSV文件加载数据。当我选择没有条件的所有数据时，它按预期工作，但是，我想忽略第一列中包含字符串.BAK的任何记录。有谁有任何洞察如何我可以实现这一点？

I'm trying to load data from a CSV file using an SQL query SELECT * FROM ["+fileName+"];. It works as expected when I select all data with no condition, however, I would like to omit any records containing the string ".BAK" in the first column. Does anyone have any insight into how I could achieve this?

我尝试了 WHERE NOT LIKE'％.BAK％'条件的变体，

I've attempted variations of the WHERE NOT LIKE '%.BAK%' condition, but I can't get them to work as expected.

感谢

推荐答案

您的CSV文件在第一行中包含列标题（例如）

If your CSV file contains, in the first line, the column headers (for example)

firstHeaderName,secondHeaderName,thirdHeaderName, ......

那么要执行的查询就是

string cmdText = "SELECT * FROM [" + filename + "] WHERE firstHeaderName NOT LIKE '%.bak%'";

如果您没有在第一行的列标题CSV。

在这种情况下，connectionstring是这样的

Things are similar if you don't have a line with the column headers in the first line of your CSV.
In this case the connectionstring is something like this

string constr = @"Provider=Microsoft.Jet.OLEDB.4.0;
                  Data Source=d:\temp\;
                  Extended Properties='text;HDR=No;FMT=Delimited'";

，您的命令文本应使用常规名称 F1

and your command text should refer to the first column using the conventional name F1

string cmdText = "SELECT * FROM [" + filename + "] WHERE F1 NOT LIKE '%.bak%'";

惯例是使用 F1 ， F2 （第二列）等。

The convention is to name the columns with F1 (the first column), F2 (the second column) and so on.

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