The following are arranged in the network: What does 1= 1 mean in the where condition in the oracle sql statement? 1= 1 is eternal, and its meaning is unconditional, that is to say, whether there is this 1= 1 in the SQL statement is ok. This 1= 1 is often used by applications to piece together conditions according to different user choices. For example, the web interface queries the user's information, and the default value is 1= 1.

The network is organized as follows:

What is the meaning of 1= 1 in the where condition in oracle sql statement?

1= 1 is eternal, which means unconditional, that is to say, it is ok to have this 1= 1 in the SQL statement.

This 1= 1 is often used by applications to piece together conditions according to different user choices.

For example, the web interface queries the user's information, where the default value is 1= 1, so that even if the user does not select any conditions, the sql query will not go wrong. If the user selects a name, then where becomes where 1= 1, and name =' user-entered name'. If other conditions are selected, just add an AND statement after the where condition. If 1= 1 is not used, it is necessary to judge whether there is a where condition in front of each additional condition. If not, where to write it ... If yes, write an and statement. Therefore, using 1= 1 at this time can simplify the complexity of the application.