Function extractUpdateColumns

backend/plugin/parser/mysql/restore.go:195–223

extractUpdateColumns extracts column names from SET assignments that belong to the original table.

(setList []*ast.Assignment, database, _ string, matchedTable *TableReference, normalColumns []string)

// extractUpdateColumns extracts column names from SET assignments that belong
// to the original table.
func extractUpdateColumns(setList []*ast.Assignment, database, _ string, matchedTable *TableReference, normalColumns []string) []string {
	var result []string
	for _, assignment := range setList {
		col := assignment.Column
		if col == nil {
			continue
		}

		if col.Schema != "" && !strings.EqualFold(col.Schema, database) {
			continue
		}

		if col.Table == "" {
			// Unqualified column: check if it belongs to the normalColumns set.
			for _, c := range normalColumns {
				if strings.EqualFold(c, col.Column) {
					result = append(result, col.Column)
					break
				}
			}
			continue
		}

		if matchedTable != nil && (col.Table == matchedTable.Alias || strings.EqualFold(col.Table, matchedTable.Table)) {
			result = append(result, col.Column)
		}
	}
	return result
}

func hasDisjointUniqueKey(ctx context.Context, rCtx base.RestoreContext, originalDatabase, originalTable string, updateColumns []string) (bool, error) {
	columnMap := make(map[string]bool)