// SelectMissingIds accepts a table name as an input and a list of ids as a source.
// It returns a new list of ids that does not exist in the destination table
//
// * tblName : a table name
// * srcIds : a source ids
// * db : a pointer to connected databased
// * Returns a new list of ids which are not from the specified table
//
// The format of sql statement is:
// WITH dna (id) AS (VALUES (5),(6),(7),(8),(9))
// SELECT id FROM dna WHERE NOT EXISTS
// (SELECT 1 from ziartists WHERE id=dna.id)
func SelectMissingIds(tblName dna.String, srcIds *dna.IntArray, db *sqlpg.DB) (*dna.IntArray, error) {
if srcIds.Length() > 0 {
val := dna.StringArray(srcIds.Map(func(val dna.Int, idx dna.Int) dna.String {
return "(" + val.ToString() + ")"
}).([]dna.String))
selectStmt := "with dna (id) as (values " + val.Join(",") + ") \n"
selectStmt += "SELECT id FROM dna WHERE NOT EXISTS\n (SELECT 1 from " + tblName + " WHERE id=dna.id)"
ids := &[]dna.Int{}
err := db.Select(ids, selectStmt)
switch {
case err != nil:
return nil, err
case err == nil && ids != nil:
slice := dna.IntArray(*ids)
return &slice, nil
case err == nil && ids == nil:
return &dna.IntArray{}, nil
default:
panic("Default case triggered. Case is not expected. Cannot select non existed ids")
}
} else {
return nil, errors.New("Empty input array")
}
}
