Why Use 1=0 and 1=1 in SQL Queries?

The expressions 1=0 and 1=1 are commonly used in SQL across many databases. Nearly all relational database management systems (RDBMS) support them. This is because they adhere to standard SQL logic.

Why use 1=0 and 1=1 in SQL Queries Example

1. Why use 1=0 and 1=1 in SQL Queries Example
   1. Where 1=0 in SQL example
   2. Where 1=0 in SQL
   3. Supported databases

Where 1=0 in SQL example

• 1=0: This condition is always false. It is often used to prevent any rows from being returned or affected. For instance, creating an empty result set.

SELECT * FROM table WHERE 1=0; -- Always returns no rows

Where 1=0 in SQL

• 1=1: This condition is always true. It’s sometimes used in dynamic SQL to make it easier to append extra AND conditions. For example:

SELECT * FROM table WHERE 1=1 AND column = 'value'; -- Always returns rows matching the column condition

Supported databases

Most RDBMS support these expressions:

• MySQL
• PostgreSQL
• Microsoft SQL Server
• Oracle
• SQLite
• MariaDB
• IBM Db2

These conditions rely on basic boolean logic, which all SQL engines handle. So, it’s a universal SQL feature, not specific to any particular database engine.