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:

snippet
UPDATE table
SET column1 = expression1,
    column2 = expression2,
    ...
    column_n = expression_n
WHERE conditions;

Update Table by selecting rocords from another table

Syntax:

snippet
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)

snippet
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.

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

Output:

Output
1 row(s) updated. 0.06 seconds

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

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

Output:

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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