added support for 1 to 1 relations and added support for n unique keys for conflict resolution during merging.
split out into two functions.
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d180a095ca
commit
eea3d349a7
1 changed files with 83 additions and 35 deletions
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@ -27,11 +27,15 @@ func mergeModels(tx boil.Executor, primaryID uint64, secondaryID uint64, foreign
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var err error
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for _, conflict := range conflictingKeys {
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err = deleteConflictsBeforeMerge(tx, conflict, primaryID, secondaryID)
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if err != nil {
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return err
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}
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}
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if len(conflict.columns) == 1 && conflict.columns[0] == conflict.objectIdColumn {
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err = deleteOneToOneConflictsBeforeMerge(tx, conflict, primaryID, secondaryID)
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} else {
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err = deleteOneToManyConflictsBeforeMerge(tx, conflict, primaryID, secondaryID)
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}
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if err != nil {
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return err
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}
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}
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for _, fk := range foreignKeys {
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// TODO: use NewQuery here, not plain sql
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@ -48,53 +52,97 @@ func mergeModels(tx boil.Executor, primaryID uint64, secondaryID uint64, foreign
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return checkMerge(tx, foreignKeys)
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}
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func deleteConflictsBeforeMerge(tx boil.Executor, conflict conflictingUniqueKey, primaryID uint64, secondaryID uint64) error {
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conflictingColumns := strmangle.SetComplement(conflict.columns, []string{conflict.objectIdColumn})
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if len(conflictingColumns) < 1 {
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return nil
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} else if len(conflictingColumns) > 1 {
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return errors.Err("this doesnt work for unique keys with more than two columns (yet)")
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}
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func deleteOneToOneConflictsBeforeMerge(tx boil.Executor, conflict conflictingUniqueKey, primaryID uint64, secondaryID uint64) error {
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query := fmt.Sprintf(
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"SELECT %s FROM %s WHERE %s IN (%s) GROUP BY %s HAVING count(distinct %s) > 1",
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conflictingColumns[0], conflict.table, conflict.objectIdColumn,
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"SELECT COUNT(*) FROM %s WHERE %s IN (%s)",
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conflict.table, conflict.objectIdColumn,
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strmangle.Placeholders(dialect.IndexPlaceholders, 2, 1, 1),
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conflictingColumns[0], conflict.objectIdColumn,
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)
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rows, err := tx.Query(query, primaryID, secondaryID)
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defer rows.Close()
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var count int
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err := tx.QueryRow(query, primaryID, secondaryID).Scan(&count)
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if err != nil {
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return errors.Err(err)
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}
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args := []interface{}{secondaryID}
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for rows.Next() {
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var value string
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err = rows.Scan(&value)
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if err != nil {
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return errors.Err(err)
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}
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args = append(args, value)
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}
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// if no rows found, no need to delete anything
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if len(args) < 2 {
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return nil
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if count > 2 {
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return errors.Err("it should not be possible to have more than two rows here")
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} else if count != 2 {
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return nil // no conflicting rows
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}
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query = fmt.Sprintf(
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"DELETE FROM %s WHERE %s = %s AND %s IN (%s)",
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"DELETE FROM %s WHERE %s = %s",
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conflict.table, conflict.objectIdColumn, strmangle.Placeholders(dialect.IndexPlaceholders, 1, 1, 1),
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conflictingColumns[0], strmangle.Placeholders(dialect.IndexPlaceholders, len(args)-1, 2, 1),
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)
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_, err = tx.Exec(query, args...)
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_, err = tx.Exec(query, secondaryID)
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return errors.Err(err)
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}
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func deleteOneToManyConflictsBeforeMerge(tx boil.Executor, conflict conflictingUniqueKey, primaryID uint64, secondaryID uint64) error {
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conflictingColumns := strmangle.SetComplement(conflict.columns, []string{conflict.objectIdColumn})
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query := fmt.Sprintf(
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"SELECT %s FROM %s WHERE %s IN (%s) GROUP BY %s HAVING count(distinct %s) > 1",
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strings.Join(conflictingColumns, ","), conflict.table, conflict.objectIdColumn,
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strmangle.Placeholders(dialect.IndexPlaceholders, 2, 1, 1),
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strings.Join(conflictingColumns, ","), conflict.objectIdColumn,
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)
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//The selectParams should be the ObjectIDs to search for regarding the conflict.
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rows, err := tx.Query(query, primaryID, secondaryID)
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if err != nil {
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return errors.Err(err)
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}
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//Since we don't don't know if advance how many columns the query returns, we have dynamically assign them to be
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// used in the delete query.
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colNames, err := rows.Columns()
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if err != nil {
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log.Fatal(err)
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}
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//Each row result of the query needs to be removed for being a conflicting row. Store each row's keys in an array.
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var rowsToRemove = [][]interface{}(nil)
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for rows.Next() {
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//Set pointers for dynamic scan
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iColPtrs := make([]interface{}, len(colNames))
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for i := 0; i < len(colNames); i++ {
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s := string("")
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iColPtrs[i] = &s
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}
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//Dynamically scan n columns
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err = rows.Scan(iColPtrs...)
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if err != nil {
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return errors.Err(err)
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}
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//Grab scanned values for query arguments
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iCol := make([]interface{}, len(colNames))
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for i, col := range iColPtrs {
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x := col.(*string)
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iCol[i] = *x
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}
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rowsToRemove = append(rowsToRemove, iCol)
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}
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defer rows.Close()
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//This query will adjust dynamically depending on the number of conflicting keys, adding AND expressions for each
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// key to ensure the right conflicting rows are deleted.
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query = fmt.Sprintf(
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"DELETE FROM %s %s",
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conflict.table,
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"WHERE "+strings.Join(conflict.columns, " = ? AND ")+" = ?",
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)
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//There could be multiple conflicting rows between ObjectIDs. In the SELECT query we grab each row and their column
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// keys to be deleted here in a loop.
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for _, rowToDelete := range rowsToRemove {
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rowToDelete = append(rowToDelete, secondaryID)
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_, err = tx.Exec(query, rowToDelete...)
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if err != nil {
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return errors.Err(err)
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}
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}
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return nil
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}
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