In Databricks Runtime 15.4 LTS and below, MERGE only considers conditions in the ON clause before evaluating multiple matches.ExamplesYou can use MERGE INTO for complex operations like deduplicating data, upserting change data, applying SCD Type 2 operations, etc. See Upsert into a Delta Lake ...
如果根据 ON 和WHEN MATCHED 子句中指定的条件,源表中的多个行与目标表中的同一行匹配,则 MERGE 操作将失败,并出现 DELTA_MULTIPLE_SOURCE_ROW_MATCHING_TARGET_ROW_IN_MERGE 错误。 根据合并的 SQL 语义,这种更新操作的类型模棱两可,因为尚不清楚应使用哪个源行来更新匹配的目标行。 你可以预处理源表来消除...
INVALID_LIMIT_LIKE_EXPRESSION, INVALID_NON_DETERMINISTIC_EXPRESSIONS, INVALID_OBSERVED_METRICS, INVALID_TIME_TRAVEL_SPEC, INVALID_TIME_TRAVEL_TIMESTAMP_EXPR, JOIN_CONDITION_IS_NOT_BOOLEAN_TYPE, MULTIPLE_TIME_TRAVEL_SPEC, MULTI_SOURCES_UNSUPPORTED_FOR_EXPRESSION, NO_MERGE_ACTION_SPECIFIED, ONLY_SECRET_...
If there are multiplewhenMatchedclauses, then they are evaluated in the order they are specified. AllwhenMatchedclauses, except the last one, must have conditions. If none of thewhenMatchedconditions evaluate to true for a source and target row pair that matches the merge condition, then the...
Yes. You can also create a pull request and merge through your Git provider. Can I delete a branch from a Databricks repo? No. To delete a branch, you must work in your Git provider. If a library is installed on a cluster, and a library with the same name is included in a folder...
keys, the_change_typemetadata fields are set toinsertanddeleteevents. Changes to primary keys can occur when manual updates are made to one of the key fields with anUPDATEorMERGEstatement or, for SCD type 2 tables, when the__start_atfield changes to reflect an earlier start sequence value....
The join conditions Join type (i.e. inner, left outer, etc.) Joiners are defined in the Feature Family and added to the primary data source. Below is the definition of a joiner that will join the store dimension to store_sales_df assuming the source df containsss_store_sk. ...
target_alias, source_alias: Aliases for the target and source to allow you to describe your merge conditions more naturally. These default to DBT_INTERNAL_DEST and DBT_INTERNAL_SOURCE, respectively. skip_matched_step: If set to true, the 'matched' clause of the merge statement will not be ...
Theranking windowfunction can be used to deduplicate data using custom, and potentially complex, logic. For example, an incoming data set could have multiple records with the same row ID, where the latest record is correct. In this case, a MERGE would not work because the same ID is found...
MERGE operations fail with a DELTA_MULTIPLE_SOURCE_ROW_MATCHING_TARGET_ROW_IN_MERGE error if more than one row in the source table matches the same row in the target table based on the conditions specified in the ON and WHEN MATCHED clauses. According to the SQL semantics of merge, this ...