Why Does My Java Code Throw a 'Column Does Not Exist' Error When Deleting from PostgreSQL?

Error: Column does not exist when Deleting from PostgreSQL with Java

Introduction

Connecting Java programs to PostgreSQL and performing CRUD operations is essential for many applications. This article addresses a common error encountered when attempting to delete data from a PostgreSQL table using Java.

The Error

When executing the following code:

con = DriverManager.getConnection(url, user, password);
String stm = "DELETE FROM hostdetails WHERE MAC = 'kzhdf'";
pst = con.prepareStatement(stm);
pst.executeUpdate();

users might encounter the error:

SEVERE: ERROR: column "mac" does not exist

Solution

When using PostgreSQL, entity names (such as tables and columns) with uppercase letters must be "escaped" using double quotes (""). Therefore, the correct code is:

String stm = "DELETE FROM hostdetails WHERE \"MAC\" = 'kzhdf'";

Prepared Statement Best Practice

Additionally, it is recommended to use prepared statements for better security and performance. The code should be updated as follows:

con = DriverManager.getConnection(url, user, password);
String stm = "DELETE FROM hostdetails WHERE \"MAC\" = ?";
pst = con.prepareStatement(stm);
pst.setString(1, "kzhdf");
pst.executeUpdate();

The above is the detailed content of Why Does My Java Code Throw a 'Column Does Not Exist' Error When Deleting from PostgreSQL?. For more information, please follow other related articles on the PHP Chinese website!