mysql: improve fields type info text resultset. #291
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mysql: fix column types for a mix of null/non-null fields.
siddontang
reviewed
Jul 6, 2018
mysql/resultset_helper.go
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| // the case, when old value was null, and the new one isn't null, so we can update | ||
| // type info for fields. | ||
| oldIsNull, newIsNull := r.Fields[j].Type == MYSQL_TYPE_NULL, typ == MYSQL_TYPE_NULL | ||
| if oldIsNull { |
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can we use
if oldIsNull && !newIsNull {
// format
} else if !oldIsNull && !newIsNull {
// return err
}to simplify the indent?
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I agree, the code looks cleaner.
|
Thank you @avdva |
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According to the current algorithm, field type is determined by the type of the first row.
If it's nullable and is
null, the type will be MYSQL_TYPE_NULL. However, other rows can have non-null value, so their type info is lost.Thus, the resultset can have different types for fields depending of what actual value was first. For example, MySQL Workbench uses this info, and if the type is MYSQL_TYPE_NULL, it shows
nullfor all rows, despite the fact, that there arenon-nullvalues.