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added support for 1 to 1 relations and added support for n unique keys for conflict resolution during merging.

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split out into two functions.
This commit is contained in:
Mark Beamer Jr 2018-09-03 00:51:55 -04:00
parent d180a095ca
commit eea3d349a7
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GPG key ID: 1C314FB89AD76973
1 changed files with 83 additions and 35 deletions
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110
templates/singleton/boil_queries.tpl
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@ -27,7 +27,11 @@ func mergeModels(tx boil.Executor, primaryID uint64, secondaryID uint64, foreign
var err error
for _, conflict := range conflictingKeys {
err = deleteConflictsBeforeMerge(tx, conflict, primaryID, secondaryID)
if len(conflict.columns) == 1 && conflict.columns[0] == conflict.objectIdColumn {
err = deleteOneToOneConflictsBeforeMerge(tx, conflict, primaryID, secondaryID)
} else {
err = deleteOneToManyConflictsBeforeMerge(tx, conflict, primaryID, secondaryID)
}
if err != nil {
return err
}
@ -48,53 +52,97 @@ func mergeModels(tx boil.Executor, primaryID uint64, secondaryID uint64, foreign
return checkMerge(tx, foreignKeys)
}
func deleteConflictsBeforeMerge(tx boil.Executor, conflict conflictingUniqueKey, primaryID uint64, secondaryID uint64) error {
conflictingColumns := strmangle.SetComplement(conflict.columns, []string{conflict.objectIdColumn})
if len(conflictingColumns) < 1 {
return nil
} else if len(conflictingColumns) > 1 {
return errors.Err("this doesnt work for unique keys with more than two columns (yet)")
}
func deleteOneToOneConflictsBeforeMerge(tx boil.Executor, conflict conflictingUniqueKey, primaryID uint64, secondaryID uint64) error {
query := fmt.Sprintf(
"SELECT %s FROM %s WHERE %s IN (%s) GROUP BY %s HAVING count(distinct %s) > 1",
conflictingColumns[0], conflict.table, conflict.objectIdColumn,
"SELECT COUNT(*) FROM %s WHERE %s IN (%s)",
conflict.table, conflict.objectIdColumn,
strmangle.Placeholders(dialect.IndexPlaceholders, 2, 1, 1),
conflictingColumns[0], conflict.objectIdColumn,
)
rows, err := tx.Query(query, primaryID, secondaryID)
defer rows.Close()
var count int
err := tx.QueryRow(query, primaryID, secondaryID).Scan(&count)
if err != nil {
return errors.Err(err)
}
args := []interface{}{secondaryID}
for rows.Next() {
var value string
err = rows.Scan(&value)
if err != nil {
return errors.Err(err)
}
args = append(args, value)
}
// if no rows found, no need to delete anything
if len(args) < 2 {
return nil
if count > 2 {
return errors.Err("it should not be possible to have more than two rows here")
} else if count != 2 {
return nil // no conflicting rows
}
query = fmt.Sprintf(
"DELETE FROM %s WHERE %s = %s AND %s IN (%s)",
"DELETE FROM %s WHERE %s = %s",
conflict.table, conflict.objectIdColumn, strmangle.Placeholders(dialect.IndexPlaceholders, 1, 1, 1),
conflictingColumns[0], strmangle.Placeholders(dialect.IndexPlaceholders, len(args)-1, 2, 1),
)
_, err = tx.Exec(query, args...)
_, err = tx.Exec(query, secondaryID)
return errors.Err(err)
}
func deleteOneToManyConflictsBeforeMerge(tx boil.Executor, conflict conflictingUniqueKey, primaryID uint64, secondaryID uint64) error {
conflictingColumns := strmangle.SetComplement(conflict.columns, []string{conflict.objectIdColumn})
query := fmt.Sprintf(
"SELECT %s FROM %s WHERE %s IN (%s) GROUP BY %s HAVING count(distinct %s) > 1",
strings.Join(conflictingColumns, ","), conflict.table, conflict.objectIdColumn,
strmangle.Placeholders(dialect.IndexPlaceholders, 2, 1, 1),
strings.Join(conflictingColumns, ","), conflict.objectIdColumn,
)
//The selectParams should be the ObjectIDs to search for regarding the conflict.
rows, err := tx.Query(query, primaryID, secondaryID)
if err != nil {
return errors.Err(err)
}
//Since we don't don't know if advance how many columns the query returns, we have dynamically assign them to be
// used in the delete query.
colNames, err := rows.Columns()
if err != nil {
log.Fatal(err)
}
//Each row result of the query needs to be removed for being a conflicting row. Store each row's keys in an array.
var rowsToRemove = [][]interface{}(nil)
for rows.Next() {
//Set pointers for dynamic scan
iColPtrs := make([]interface{}, len(colNames))
for i := 0; i < len(colNames); i++ {
s := string("")
iColPtrs[i] = &s
}
//Dynamically scan n columns
err = rows.Scan(iColPtrs...)
if err != nil {
return errors.Err(err)
}
//Grab scanned values for query arguments
iCol := make([]interface{}, len(colNames))
for i, col := range iColPtrs {
x := col.(*string)
iCol[i] = *x
}
rowsToRemove = append(rowsToRemove, iCol)
}
defer rows.Close()
//This query will adjust dynamically depending on the number of conflicting keys, adding AND expressions for each
// key to ensure the right conflicting rows are deleted.
query = fmt.Sprintf(
"DELETE FROM %s %s",
conflict.table,
"WHERE "+strings.Join(conflict.columns, " = ? AND ")+" = ?",
)
//There could be multiple conflicting rows between ObjectIDs. In the SELECT query we grab each row and their column
// keys to be deleted here in a loop.
for _, rowToDelete := range rowsToRemove {
rowToDelete = append(rowToDelete, secondaryID)
_, err = tx.Exec(query, rowToDelete...)
if err != nil {
return errors.Err(err)
}
}
return nil
}