Data Manipulation Language

The BigQuery Data Manipulation Language (DML) enables you to update, insert, and delete data from your BigQuery tables.

You can execute DML statements just as you would a SELECT statement, with the following conditions:

• You must use standard SQL. To enable standard SQL, see Switching SQL dialects.

• You cannot specify a destination table. For example, in the web UI you must have Destination Table set to No table selected.

  

Limitations

• Each DML statement initiates an implicit transaction, which means that changes made by the statement are automatically committed at the end of each successful DML statement. There is no support for multi-statement transactions.

• Only the following combinations of DML statements are allowed to run concurrently on a table:

  • UPDATE and INSERT
  • DELETE and INSERT
  • INSERT and INSERT

  Otherwise, one of the DML statements will be aborted. For example, if two UPDATE statements execute simultaneously against the table then only one of them will succeed.

• Rows that were written to a table recently via streaming (using the tabledata.insertall method) cannot be modified using UPDATE, DELETE, or MERGE statements. Recent writes are typically those that occur within the last 30 minutes. Note that all other rows in the table remain modifiable by using UPDATE, DELETE, or MERGE statements.

• Correlated subqueries within a when_clause, search_condition, merge_update_clause or merge_insert_clause are not supported for MERGE statements.

• If there are only INSERT clauses (there can be more than one), the MERGE statement behaves like an INSERT statement. An INSERT-only MERGE statement can run concurrently with other DML statements (INSERT, UPDATE, DELETE, or MERGE).

  If the MERGE statement is not limited to INSERT clauses (it has one or more UPDATE or DELETE clauses), the statement cannot run concurrently with other MERGE statements containing UPDATE or DELETE clauses. The statement also cannot run concurrently with any other DELETE or UPDATE statements.

• Queries that contain Data Manipulation Language (DML) statements cannot use a wildcard table as the target of the query. For example, a wildcard table may be used in the FROM clause of an UPDATE query, but a wildcard table cannot be used as the target of the UPDATE operation.

Quotas

For information on DML quota information, see DML statements on the Quotas and Limits page.

Pricing

For information on DML pricing, see Data Manipulation Language pricing on the Pricing page.

What's next

• See DML syntax and samples on the DML syntax page.