How to correctly read DECIMAL values from MySQL with QSqlQuery
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wrote on 29 Jan 2018, 18:48 last edited by deleted602
Having a table in MySQL with a column of type DECIMAL, I am wondering how to read this value properly in my Qt application. To me it seems like it is handled like a double when you retrieve it using QSqlQuery. Is this correct? Doesn't this risk losing precision?
To quote https://spin.atomicobject.com/2014/08/14/currency-rounding-errors/
Now that the database is storing the monetary values accurately, you don’t want to do anything to lose that accuracy when retrieving values from it. [...] when using Java’s Hibernate ORM, you need to specify the variable as a BigDecimal not a Float or Double
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Hi,
Indeed, DECIMAL is mapped to double in the MySQL plugin.
You should do some testing with the values you are going to use.
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wrote on 29 Jan 2018, 20:51 last edited by
What does this mean exactly? That the SQL classes of Qt cannot be used if you want the precision of DECIMAL?
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As it is now, double is used.
Depending on how your DECIMAL filed is configured, it might be enough. If not, then you can modify the plugin to read the field as described here.
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