DML, Transactions and Data Integrity

Apex ProgrammingDML, Transactions and Data IntegrityWrite data safely from Apex: DML statements vs Database methods, partial success and error handling, upserts with external IDs, merge and undelete, transaction boundaries and savepoints, mixed DML, record locking and user-mode DML.Intermediate · about 75 minutesWhat you will learn

Choose between DML statements and Database methods and process SaveResult errors

Upsert records with external IDs and set relationships by external ID without querying

Explain what an Apex transaction is, what is committed and when, and use savepoints correctly

Diagnose and work around MIXED_DML_OPERATION and UNABLE_TO_LOCK_ROW errors

Enforce the user's permissions in DML with 'as user' and AccessLevel.USER_MODE

Use DMLOptions for assignment rules, duplicate rules and field truncation

Contents

DML statements vs Database methods

Upsert and external IDs

Delete, undelete and the Recycle Bin

Merge

Converting leads

DMLOptions

Transactions: what commits, and when

Mixed DML: setup vs non-setup objects

Record locking and concurrency

Access level in DML: user mode vs system mode

Async DML patterns

Toward a Unit of Work

Worked example: an idempotent order ingestion service

Best practices

Common pitfalls

Hands-on exercises

Key takeaways