REQUEST COMPLIMENTARY SQLS*PLUS LICENCE
PostgreSQL UPDATE statement
The PostgreSQL UPDATE statement is used to update existing table entries in a PostgreSQL database.
The syntax for the UPDATE statement when updating a single table in PostgreSQL
UPDATE table
SET column1 = expression1_id | DEFAULT,
column2 = expression2_id | DEFAULT,
…
[WHERE conds];
Parameters and arguments of the statement
- column1, column2 – Columns that you want to update.
- expression1_id, column2_id – New values for assigning column1, column2. Therefore, column1 will be assigned the value expression1, column2 will be assigned the value2, etc.
- DEFAULT – The default value for this particular column in the table. If the default value for a column is not set, the column will be set to NULL.
- WHERE conds – Optional. The conditions that must be met to perform the update. If no conditions are set, all entries in the table will be updated.
Example of how to update a single column
Let’s look at a very simple example of a PostgreSQL UPDATE query.
UPDATE contacts
SET first_name = 'Helen'
WHERE contact_id = 35;
In this example, the value of first_name will be updated to ‘Helen’ in the contacts table, where contact_id is 35.
You can also use the keyword DEFAULT to set the default value for the column.
For example,
UPDATE contacts
SET first_name = DEFAULT
WHERE contact_id = 35;
In this example, the first_name will be updated to the default value for the field in the contacts table, where contact_id is 35. If the default value is not present in the contacts table, the first_name column will be set to NULL.
Example how to update several columns
Consider the UPDATE example for PostgreSQL, where you can update several columns with one UPDATE statement.
UPDATE contacts
SET city = 'Abilene',
state = 'Beaumont'
WHERE contact_id >= 200;
If you want to update multiple columns, you can do so by separating the column/value pairs with commas.
In this PostgreSQL example of UPDATE, the value of the city will be changed to ‘Abilene’ and the state will be changed to ‘Beaumont’ where contact_id is greater than or equal to 200.
PostgreSQL: How to Update Records | Course
MORE NEWS
PreambleNoSql is not a replacement for SQL databases but is a valid alternative for many situations where standard SQL is not the best approach for...
PreambleMongoDB Conditional operators specify a condition to which the value of the document field shall correspond.Comparison Query Operators $eq...
5 Database management trends impacting database administrationIn the realm of database management systems, moreover half (52%) of your competitors feel...
The data type is defined as the type of data that any column or variable can store in MS SQL Server. What is the data type? When you create any table or...
PreambleMS SQL Server is a client-server architecture. MS SQL Server process starts with the client application sending a query.SQL Server accepts,...
First the basics: what is the master/slave?One database server (“master”) responds and can do anything. A lot of other database servers store copies of all...
PreambleAtom Hopper (based on Apache Abdera) for those who may not know is an open-source project sponsored by Rackspace. Today we will figure out how to...
PreambleMongoDB recently introduced its new aggregation structure. This structure provides a simpler solution for calculating aggregated values rather...
FlexibilityOne of the most advertised features of MongoDB is its flexibility. Flexibility, however, is a double-edged sword. More flexibility means more...
PreambleSQLShell is a cross-platform command-line tool for SQL, similar to psql for PostgreSQL or MySQL command-line tool for MySQL.Why use it?If you...
PreambleWriting an application on top of the framework on top of the driver on top of the database is a bit like a game on the phone: you say “insert...
PreambleOracle Coherence is a distributed cache that is functionally comparable with Memcached. In addition to the basic function of the API cache, it...
PreambleIBM pureXML, a proprietary XML database built on a relational mechanism (designed for puns) that offers both relational ( SQL / XML ) and...
What is PostgreSQL array? In PostgreSQL we can define a column as an array of valid data types. The data type can be built-in, custom or enumerated....
PreambleIf you are a Linux sysadmin or developer, there comes a time when you need to manage an Oracle database that can work in your environment.In this...
PreambleStarting with Microsoft SQL Server 2008, by default, the group of local administrators is no longer added to SQL Server administrators during the...