Sql on duplicate key update oracle

The following code selects the most current record for every duplicate pair of col1 and col2. Learn the about the logical columns that are not exist in the table, but how can be used to select the data from the table, with explanation and example queries. A rowid is assigned to a row upon insert and is immutable never changing , changes happen only inthe following situations. Rowid, Rownum are the Pseudo columns in oracle used to select the data from tables. ROWID is the permanent unique identifiers for each row in the database.

Statements That Cause an Implicit Commit. Restrictions on XA Transactions. Replication Statements. Functions which Configure the Source List. Function which Configures Group Replication Primary. Functions which Configure the Group Replication Mode. Compound Statement Syntax. Variables in Stored Programs. Local Variable Scope and Resolution. Flow Control Statements.

Restrictions on Server-Side Cursors. Restrictions on Condition Handling. To work around this restriction, rewrite the UNION as a derived table so that its rows can be treated as a single-table result set. For example, this statement produces an error:. Such statements produce a warning in the error log when using statement-based mode and are written to the binary log using the row-based format when using MIXED mode. Bug , Bug Whether a view can be updated depends on the keys from the underlying table or tables.

The answer to the question of whether or not a particular view is updatable is directly related to the difference between simple and complex views.

Generally, DML can be performed against the view if the base table is key-preserved. Thus, with complex views, some columns may be updated and some may not. This is decided by the table from which the column comes and if there is a primary key or key-preserved value that can be determined.