Updating table in oracle

The command returns the table to the state it was in before the Oracle updates.

To change the contract number for author A109 to 999, use the statement below.

updating table in oracle-7

If this is something you need to do all the time, I would suggest something else, but for a one-off or very small tables it should be sufficient.

@a_horse_with_no_name: Oracle does not directly support the JOIN keyword in an UPDATE, but it allows UPDATE involving JOIN operations between table in at least 2 different ways, look at the accepted answer here: stackoverflow.com/questions/2446764/…

You could create a trigger on table B that updates table A every time field_2 on table B is updated.

UPDATE dest_tab tt SET (tt.code, tt.description) = (SELECT st.code, st.description FROM source_tab st WHERE = tt.id) WHERE EXISTS (SELECT 1 FROM source_tab WHERE id = tt.id); 5000 rows updated.

SQL ----------------------------------------------------------------------------------------------- | Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | ----------------------------------------------------------------------------------------------- | 0 | UPDATE STATEMENT | | 4999 | 185K| 30013 (34)| | | 1 | UPDATE | dest_tab | | | | | | 2 | NESTED LOOPS SEMI | | 4999 | 185K| 19 (6)| | | 3 | TABLE ACCESS FULL | dest_tab | 10000 | 332K| 18 (0)| | |* 4 | INDEX UNIQUE SCAN | source_tab_PK | 2500 | 10000 | 0 (0)| | | 5 | TABLE ACCESS BY INDEX ROWID| source_tab | 1 | 43 | 2 (0)| | |* 6 | INDEX UNIQUE SCAN | source_tab_PK | 1 | | 1 (0)| | ----------------------------------------------------------------------------------------------- Predicate Information (identified by operation id): --------------------------------------------------- 4 - access("ID"="TT"."ID") 6 - access("ST"."ID"=: B1) UPDATE (SELECT tt.id, tt.code, tt.description, AS st_code, st.description AS st_description FROM dest_tab tt, source_tab st WHERE = st.id) ilv SET = ilv.st_code, ilv.description = ilv.st_description; 5000 rows updated.

The Oracle UPDATE statement locates one or more rows (or all the rows) in a table and sets one or more columns to the specified values.

As with the INSERT statement, the values must either match the columns data type or one that the database can implicitly convert.

The basic format is: Let's go back to the AUTHOR table and look at some examples of Oracle updates.

As with the INSERT section, I rolled back the changes to the original table.

To set each author contract number to zero, simply leave off the WHERE clause.

If you do not specify a row, then all rows are updated when Oracle update is used.

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