Why Does My PostgreSQL Query Return 'column name does not exist' Despite Using Quotes?

Postgresql Statement Error: Column Name Does Not Exist

In PostgreSQL databases, an error message stating "column name does not exist" may occur when attempting to execute a query with a specific column name quoted.

Problem Description:

The user faces an issue while querying a simple PostgreSQL database with a table containing a column named "lName" (uppercase N). Despite quoting the column name as required, an error is returned, indicating that the column "Smith" does not exist.

Solution:

The problem lies in the incorrect format of the string literal used in the LIKE clause. In PostgreSQL, string literals must be enclosed in single quotes ('), not double quotes (").

Correct Query:

SELECT *
FROM employee
WHERE "lName" LIKE 'Smith'

Explanation:

Double quotes (") within the LIKE clause denote a quoted identifier, not a string literal. Therefore, the query erroneously interpreted "Smith" as a column name rather than a string comparison value.

Additional Notes:

1. Consider including a wildcard in the LIKE clause, as it allows for partial string matches.
2. Ensure that the column name exists in the specified table to avoid similar errors.

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