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This Oracle tutorial explains how to use the Oracle UPDATE statement with syntax, examples, and practice exercises. The Oracle UPDATE statement is used to update existing records in a table in an Oracle database. There are 2 syntaxes for an update query in Oracle.
This tutorial shows you how to use Oracle UPDATE statement to change existing values in a table. It also provides some practical examples of updating data.
UPDATE. Use the UPDATE statement to change existing values in a table or in the base table of a view or the master table of a materialized view. For you to update values in a table, the table must be in your own schema or you must have the UPDATE object privilege on the table.
- Setup
- Subquery Method
- Inline View Method
- Merge Statement Method
The DEST_TAB table contains 10,000 rows. The SOURCE_TAB table contains 5,000 rows, each of which has a matching key value with a row from the DEST_TAB table, but different data in the CODE and DESCRIPTIONcolumns. At this point we can see none of the values in the DESCRIPTION column of the DEST_TABtable contain the word "Updated". The aim is to upda...
The first option is to do an update of the DEST_TAB table using a subquery to pull the correct data from the SOURCE_TAB table. Notice the EXISTS predicate to exclude rows from the DEST_TAB table with no matching row in the SOURCE_TABtable. Without this, the unmatched rows will have their values set to NULL. The execution plan for the current data v...
The second option is to join the two tables as an inline view and base the update on that. The execution plan for the current data volume is shown below. If the workload is sufficiently large and the server can cope with the extra workload, the PARALLELhint can be used to make this run in parallel. The number of rows updated can be altered by addin...
The third option is to use the MERGE statement, omitting the WHEN NOT MATCHEDclause as it is not needed. The execution plan for the current data volume is shown below. If the workload is sufficiently large and the server can cope with the extra workload, the PARALLELhint can be used to make this run in parallel. Remember, you can use queries as the...
The first syntactical form, called a searched update, updates the value of one or more columns for all rows of the table for which the WHERE clause evaluates to TRUE. The second syntactical form, called a positioned update, updates one or more columns on the current row of an open, updatable cursor.
9 juin 2023 · The article focuses on the basic syntax and types of SQL INSERT statements in Oracle, including single row and inserts from SELECT statements with examples. Additionally, it covers the basic syntax of UPDATE and DELETE statements in Oracle.
10 sept. 2012 · example: UPADTE ER_FORMSLINEAR SET col59 = REPLACE(col59,'[Umbilical Artery Catheter (UAC) or Peripheral Arterial Access]','[Umbilical Artery Catheter (UAC)]') from ER_FORMSLINEAR where fk_form=327 and col59 like '%[Umbilical Artery Catheter (UAC) or Peripheral Arterial Access]%';
