Fetch(conn,statement) returning int64 instead of float or double

Question

Frank Schiro 2018-12-25

1
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/437144-fetch-conn-statement-returning-int64-instead-of-float-or-double

评论： James Maniscalco 2020-5-19

I am trying to import data from SQLite with fetch. It is importing the data as int64. I would like it to import with the data type of double because with int 64 I am either getting 1 or 0, but the values I am looking at are 0.63, ect.

How can I make fetch(conn,statement) import as datetype double instead of int64? I can't find it in the documentation.

These are the commands I am running :

statement=strcat("select val from historical where sym like '",SYM,"' and Tag like 'EPS'");
y=fetch(conn,statement);

Data I am getting back looks like this :

Columns 1 through 36

1 0 0 0 0 0 0 0 0 2 6 0 0 0 0 1 0 0 1 0 0 1 1 0 1 1 1 0 1 1 0 0 0 0 0 0

But the data in my SQLite database looks like this:

1

0.63

0.71

-0.13

0.45

0.48

0.49

0.46

0.24

2.19

6.12

0.38

0

0.6

0.78

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Walter Roberson 2018-12-25

You might need to configure JDBC

https://www.mathworks.com/help/database/ug/configuring-driver-and-data-source.html

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Answer 1

Hitesh Kumar Dasika 2018-12-27

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/437144-fetch-conn-statement-returning-int64-instead-of-float-or-double#answer_354132

This is a known issue in MATLAB R2018b. This issue is fixed in the latest update of R2018b. Please check for the product updates of your installation.

check for Updates

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Frank Schiro 2020-5-18

I switched to R hahaha

James Maniscalco 2020-5-19

In the end I managed to rewrite my app to use a JDBC driver connection instead of SQLite for MATLAB. The JDBC version returns the correct values from the database.

As for making the switch, the two methods aren't totally interchangeable vis-a-vis function names and data types (e.g. cell vs table) but they are decently close. I would have preferred to use SQLite for MATLAB to avoid external dependencies, but oh well.

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