Oracle UPDATE Statement

In Oracle, UPDATE statement is used to update the existing records in a table. You can update a table in 2 ways.

Traditional Update table method

Syntax:

UPDATE table  

SET column1 = expression1,  

    column2 = expression2,  

    ...  

    column_n = expression_n  

WHERE conditions; 

    Update Table by selecting rocords from another table

    Syntax:

    UPDATE table1  
    
    SET column1 = (SELECT expression1  
    
                   FROM table2  
    
                   WHERE conditions)  
    
    WHERE conditions;

    Parameters:

    1) column1, column2, … column_n:

    It specifies the columns that you want to update.

    2) expression1, expression2, …expression_n:

    This specifies the values to assign to the column1, column2, ?. column_n.

    3) conditions:It specifies the conditions that must be fulfilled for execution of UPDATE stateme.

    Oracle Update Example: (Update single column)

    UPDATE suppliers  
    
    SET supplier_name = 'Kingfisher'  
    
    WHERE supplier_id = 2;

    This example will update the supplier_name as “Kingfisher” where “supplier_id” is 2.

    Oracle Update Example: (Update multiple columns)

    The following example specifies how to update multiple columns in a table. In this example, two columns supplier_name and supplier_address is updated by a single statement.

    UPDATE suppliers  
    
    SET supplier_address = 'Agra',  
    
        supplier_name = 'Bata shoes'  
    
    WHERE supplier_id = 1;  

      Output:

      1 row(s) updated.
      0.06 seconds
      

      Oracle Update Example: (By selecting records from another table)

      UPDATE customers  
      
      SET name = (SELECT supplier_name  
      
                       FROM suppliers  
      
                       WHERE suppliers.supplier_name = customers.name)  
      
      WHERE age < 25;

      Output:

      2 row(s) updated.
      0.02 seconds
      

      Here, the customers table is updated by fetching the data from “suppliers” table.


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