InsertStmt: automatically add insert columns when using InsertStmt.Record()

[brunotm]

This change automatically adds the insert columns when using
InsertStmt.Record() if they are not set by calling Columns().

Calling Columns() afterwards still maintains the same behaviour as it
overwrites the Column field.

Since there is no API incompatibility, this change was made on the
existing Record() function.

[jiyeyuran]

there is a bug on changing fields

[brunotm]

Hello @jiyeyuran, can you elaborate on that?
Thanks

[jiyeyuran]

if len(b.Column) == 0 {
        // 'fields' is  cached in tagStore
	fields := s.get(v.Type())
	var i int
	for x := 0; x < len(fields); x++ {
		if fields[x] != "" {
                         // this also changed the cached fields 
			fields[i] = fields[x]
			i++
		}
	}
	b.Columns(fields[:i]...)
}

[brunotm]

@jiyeyuran the tagstore is intialized on each Record() call with s := newTagStore(), what do you mean by cached?

The only "problem" here would be calling Record() multiple times with different struct types for which the initialised columns for the 1st struct would not match the 2nd struct columns. But this "problem" already exists if the provided struct fields don't match the specified Columns() call.

There is actually room for improvement if we make the tagstore part of the insert statement and reutilise it for both Record calls and struct validation between calls

[jiyeyuran]

The bug will show if you add test like below:

type insertTest struct {
	A int
        D string `db:"-"`
	C string `db:"b"`
	u int
}

You also need to ignore the id field with zero value.

[jiyeyuran]

No bug version:

if len(b.Column) == 0 {
	fields := s.get(v.Type())
	for i, field := range fields {
		if field == "id" {
			if idField := v.Field(i); idField.IsZero() {
				continue
			}
		}
		if field != "" {
			b.Column = append(b.Column, field)
		}
	}
}

[brunotm]

@jiyeyuran got it, thanks. I have updated the PR with the suggested changes.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.