Difference Between
versus

ALTER Command vs. UPDATE Command: Know the Difference

Shumaila Saeed
By Shumaila Saeed || Published on February 20, 2024
The ALTER Command modifies the structure of a database table, while the UPDATE Command modifies the data within a table.
ALTER Command vs. UPDATE Command

Key Differences

The ALTER Command is used in database management systems to change the structure of existing tables. This can include adding, deleting, or modifying columns and constraints. In contrast, the UPDATE Command is designed to modify the actual data within the table's rows. It changes the values of the specified columns in one or more rows.
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024
With the ALTER Command, database administrators can adapt the schema of a table to evolving data requirements without affecting the stored data. Conversely, the UPDATE Command directly impacts the data contained in the table, altering the contents of existing rows without changing the table's overall structure.
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024
The ALTER Command is essential for maintaining the long-term integrity and relevance of the database schema. The UPDATE Command, on the other hand, is more about the day-to-day manipulation of the data within the database, ensuring that the information remains current and accurate.
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024
The scope of the ALTER Command is structural: it affects how data can be stored or constrained. The UPDATE Command's scope is data-centric, focusing on modifying what is already stored within the database's existing framework.
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024
The ALTER Command often requires careful planning and consideration due to its impact on database structure. In contrast, the UPDATE Command is commonly used for routine data maintenance and is a regular part of database operations.
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024
ADVERTISEMENT

Comparison Chart

Functionality

Modifies table structure
Modifies table data
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024

Usage

Used to add, delete, or modify columns and constraints
Used to change existing data in table rows
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024

Impact on Data

Does not alter existing data
Directly alters the data in the rows
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024

Long-term vs Short-term

More for long-term schema maintenance
More for short-term data management
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024

Requirement of Planning

Requires careful planning due to structural impact
Often used routinely, less planning required
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024
ADVERTISEMENT

ALTER Command and UPDATE Command Definitions

ALTER Command

ALTER Command can be used to change table constraints.
To enforce data integrity, an ALTER Command was used to add a unique constraint.
Shumaila Saeed
Shumaila Saeed
Jan 16, 2024

UPDATE Command

UPDATE Command is a SQL statement for data alteration within a table.
Employee salaries were increased using an UPDATE Command.
Shumaila Saeed
Shumaila Saeed
Jan 16, 2024

ALTER Command

ALTER Command is used to modify the schema of a database table.
To accommodate phone numbers, we issued an ALTER Command to include an additional column.
Shumaila Saeed
Shumaila Saeed
Jan 16, 2024

UPDATE Command

UPDATE Command changes values in table rows.
An UPDATE Command updated the stock levels in the inventory table.
Shumaila Saeed
Shumaila Saeed
Jan 16, 2024

ALTER Command

ALTER Command adjusts the structure of a database table.
The database admin used the ALTER Command to add a new column for email addresses.
Shumaila Saeed
Shumaila Saeed
Jan 16, 2024
ADVERTISEMENT

UPDATE Command

UPDATE Command allows for conditional data modification.
To mark orders as delivered, an UPDATE Command was executed where the status matched 'Shipped'.
Shumaila Saeed
Shumaila Saeed
Jan 16, 2024

ALTER Command

ALTER Command enables the addition or deletion of columns in a table.
We removed an obsolete column using the ALTER Command.
Shumaila Saeed
Shumaila Saeed
Jan 16, 2024

UPDATE Command

UPDATE Command is used to refresh table data.
A batch UPDATE Command was run to synchronize the user data with the latest information.
Shumaila Saeed
Shumaila Saeed
Jan 16, 2024

ALTER Command

ALTER Command is a SQL statement for changing table architecture.
The ALTER Command was executed to change the data type of the salary column.
Shumaila Saeed
Shumaila Saeed
Jan 16, 2024

UPDATE Command

UPDATE Command modifies existing data in a database table.
The UPDATE Command was used to correct the email address of a customer.
Shumaila Saeed
Shumaila Saeed
Jan 16, 2024

Repeatedly Asked Queries

Can ALTER Command add constraints?

Yes, it can add or modify constraints in a table.
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024

Does ALTER Command affect table data?

No, it modifies the table's structure, not the data itself.
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024

What does the ALTER Command do?

The ALTER Command changes the structure of a database table.
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024

Can ALTER Command be used to rename a table?

Yes, ALTER Command can rename a table.
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024

Is the ALTER Command reversible?

It depends on the alteration; some changes like adding a column are reversible, others are not.
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024

Can the ALTER Command change a column's data type?

Yes, it can change a column's data type if compatible.
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024

What happens if no WHERE clause is used in an UPDATE Command?

Without a WHERE clause, all rows in the table may be updated.
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024

Can ALTER Command affect database performance?

Yes, particularly if it involves large tables or complex changes.
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024

What is the primary use of the UPDATE Command?

The primary use is to modify existing data in a table.
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024

Can UPDATE Command update multiple rows at once?

Yes, it can update multiple rows based on the specified criteria.
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024

Can the ALTER Command add a primary key to a table?

Yes, it can be used to add or modify a table's primary key.
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024

How does the UPDATE Command handle data integrity?

It must comply with all constraints and rules defined in the table schema.
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024

Can UPDATE Command change the structure of a table?

No, it only changes the data within the table.
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024

Can the ALTER Command merge two columns?

No, it cannot merge columns; this requires a combination of commands and operations.
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024

Is it possible to rollback an UPDATE Command?

Yes, but only if the database transaction has not been committed yet.
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024

Is the UPDATE Command reversible?

Only if the previous data is known or backed up.
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024

Does the UPDATE Command work with JOINs?

Yes, it can be used with JOINs to update based on data in other tables.
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024

Does the UPDATE Command require a WHERE clause?

While not mandatory, a WHERE clause is recommended to target specific rows.
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024

Is ALTER Command specific to SQL databases?

Yes, it is a command used in SQL databases.
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024

How does UPDATE Command handle NULL values?

UPDATE Command can set a column's value to NULL or change it from NULL if allowed by the column's definition.
Shumaila Saeed
Shumaila Saeed
Feb 20, 2024

Share this page

Link for your blog / website
HTML
Link to share via messenger
About Author
Shumaila Saeed
Written by
Shumaila Saeed
Shumaila Saeed, an expert content creator with 6 years of experience, specializes in distilling complex topics into easily digestible comparisons, shining a light on the nuances that both inform and educate readers with clarity and accuracy.

Popular Comparisons

Trending Comparisons

FPTP vs. PRFPTP vs. PR
Shumaila SaeedShumaila Saeed
February 16, 2024
FPTP (First Past the Post) is a simple plurality voting system where the candidate with most votes wins; PR (Proportional Representation) allocates seats based on the proportion of votes each party receives.
Japanese Eyes vs. Chinese EyesJapanese Eyes vs. Chinese Eyes
Shumaila SaeedShumaila Saeed
December 25, 2023
Japanese Eyes and Chinese Eyes refer to linguistic structures in Japanese and Chinese respectively, each reflecting unique aspects of grammar and syntax.
Poem vs. PoetryPoem vs. Poetry
Shumaila SaeedShumaila Saeed
December 25, 2023
A poem is a piece of writing that expresses ideas and emotions with a distinctive style and rhythm; poetry is the art form of writing such pieces.
2 Pole Motors vs. 4 Pole Motors2 Pole Motors vs. 4 Pole Motors
Shumaila SaeedShumaila Saeed
December 25, 2023
2 Pole Motors have one pair of magnetic poles and run at higher speeds, while 4 Pole Motors have two pairs of poles and operate at lower speeds, offering higher torque.
Login vs. LogonLogin vs. Logon
Shumaila SaeedShumaila Saeed
December 25, 2023
"Login" and "Logon" are often used interchangeably to describe the process of gaining access to a computer system, but "login" can also refer to the credentials used for access.
Extent vs. ScopeExtent vs. Scope
Shumaila SaeedShumaila Saeed
December 25, 2023
"Extent" refers to the degree or range something covers, while "Scope" relates to the breadth or range of coverage, influence, or effect.
Pulley vs. SheavePulley vs. Sheave
Hifza NasirHifza Nasir
April 4, 2024
A pulley is a wheel on an axle designed to support movement and change of direction of a taut cable, while a sheave is the wheel part of a pulley system that specifically interacts with the cable.
Nuclear Family vs. Joint FamilyNuclear Family vs. Joint Family
Shumaila SaeedShumaila Saeed
January 9, 2024
Nuclear Family is a family unit consisting of parents and their children. Joint Family is a larger family structure comprising parents, children, and other relatives living together.
NM3 vs. M3NM3 vs. M3
Hifza NasirHifza Nasir
April 19, 2024
NM3 measures gas volume under Normal conditions (0°C and 1.01325 bar), while M3 measures volume under the conditions at which it is measured, without standard adjustment.
Catapult vs. TrebuchetCatapult vs. Trebuchet
Shumaila SaeedShumaila Saeed
January 4, 2024
A catapult is a ballistic device using tension or torsion to launch projectiles, while a trebuchet is a type of catapult using a counterweight for greater force and distance.
Slazenger Logo vs. Puma LogoSlazenger Logo vs. Puma Logo
Shumaila SaeedShumaila Saeed
February 15, 2024
The Slazenger logo features a panther, symbolizing agility and tradition, while the Puma logo depicts a leaping puma, representing speed and strength.
Vital Proteins Collagen vs. OrganikaVital Proteins Collagen vs. Organika
Shumaila SaeedShumaila Saeed
February 9, 2024
Vital Proteins Collagen is a brand offering collagen supplements for health and beauty, while Organika is a broader health and wellness brand with diverse products including collagen.
Data Roaming vs. Cellular DataData Roaming vs. Cellular Data
Shumaila SaeedShumaila Saeed
December 25, 2023
Data Roaming allows usage of mobile network services outside of the home network area, while Cellular Data is using mobile services within the home network.
5'11" vs. 6'0"5’11” vs. 6’0″
Shumaila SaeedShumaila Saeed
February 4, 2024
The difference between 5'11" and 6'0" is one inch, with 5'11" being 71 inches and 6'0" being 72 inches tall.
Pycharm Community vs. Pycharm ProPycharm Community vs. Pycharm Pro
Shumaila SaeedShumaila Saeed
February 4, 2024
PyCharm Community is a free, open-source IDE for Python development, while PyCharm Pro is a paid version with additional advanced features like web development support and database tools.
4D Battery vs. 8D Battery4D Battery vs. 8D Battery
Shumaila SaeedShumaila Saeed
February 7, 2024
4D batteries are smaller, heavy-duty batteries used in commercial applications, whereas 8D batteries are larger, providing more power and capacity for large vehicles and machinery.
Gorilla Glass 3 vs. Gorilla Glass 5Gorilla Glass 3 vs. Gorilla Glass 5
Shumaila SaeedShumaila Saeed
January 1, 2024
Gorilla Glass 3 offers improved scratch resistance and durability compared to its predecessors, while Gorilla Glass 5 focuses on enhanced drop protection and toughness.
DDR3 vs. DDR3LDDR3 vs. DDR3L
Shumaila SaeedShumaila Saeed
January 29, 2024
DDR3 is a type of RAM with standard voltage (1.5V), while DDR3L is a low voltage variant (1.35V) compatible with both 1.5V and 1.35V slots.
Explain vs. DefineExplain vs. Define
Dua FatimaDua Fatima
June 22, 2024
Explaining involves detailing or clarifying a concept, often including context and examples, whereas defining means stating the exact meaning of a word or phrase, typically in a concise manner.
Traditional Trade vs. Modern TradeTraditional Trade vs. Modern Trade
Shumaila SaeedShumaila Saeed
December 25, 2023
Traditional trade involves local, small-scale, often personalized commerce; modern trade is characterized by large-scale, technology-driven, and impersonal retail environments.
NDM vs. FTPNDM vs. FTP
Shumaila SaeedShumaila Saeed
February 15, 2024
NDM (Network Data Mover) automates and secures data transfers across networks, while FTP (File Transfer Protocol) is a standard network protocol for transferring files between computers.
Fluid vs. LiquidFluid vs. Liquid
Shumaila SaeedShumaila Saeed
February 13, 2024
Fluids encompass all substances that flow (including gases and liquids), while liquids specifically refer to fluids with a definite volume but no fixed shape, adapting to their container.
Crane vs. HeronCrane vs. Heron
Shumaila SaeedShumaila Saeed
June 24, 2024
Cranes are large, long-legged and long-necked birds known for their elaborate dances, while herons are typically more solitary, stealth hunters with a distinctive S-shaped neck.
Char vs. VarcharChar vs. Varchar
Dua FatimaDua Fatima
June 23, 2024
Char stores fixed-length strings; efficient for known sizes. Varchar stores variable-length strings, saving space for shorter inputs.

Featured Comparisons

New Comparisons