What does “ERROR: syntax error at or near “identifier”” mean and how do you diagnose and fix it?

by

The error message ERROR: syntax error at or near "identifier" in PostgreSQL indicates that there is a syntax mistake in the SQL query near the specified “identifier”. The term “identifier” in the error message will be replaced by the specific keyword, operator, or name that PostgreSQL has identified as being incorrectly used or placed in the query. Here’s how to diagnose and fix this error:

Diagnose

  1. Identify the Location: Look at the query at the point where the “identifier” is mentioned in the error message. This will give you a clue about where the syntax error might be.
  2. Check for Typos: Ensure that the keywords, function names, operators, and identifiers (like table or column names) around the mentioned “identifier” are spelled correctly.
  3. Syntax Check: Review the syntax of the SQL command you are using. Make sure that all parentheses are properly opened and closed, strings are correctly quoted, and clauses are in the correct order.
  4. Reserved Words: If you’re using a reserved word as an identifier, ensure that it is quoted. PostgreSQL will throw a syntax error if it encounters a reserved word where it expects an identifier.
  5. Object Names: Ensure that the table names, column names, and other object names are correctly referenced. Remember that, by default, PostgreSQL converts unquoted identifiers to lowercase.

Fix

To fix the error, you need to correct the syntax based on what you find during the diagnosis:

  • Correct any typos or misspellings in the query.
  • If you’re missing a comma, a quote, or a parenthesis, add it to the appropriate place in the query.
  • Ensure that all SQL keywords are used correctly and in the right context.
  • Quote reserved words and identifiers that have mixed case or special characters if they were created as such.
  • Verify that the order of clauses in your SQL statement is correct (e.g., SELECT columns before FROM clause, WHERE clause after FROM clause, etc.).

Here’s an example of a syntax error and how you might fix it:

Original Query (with error):

SELECT * FRM table_name;

Error Message:

ERROR: syntax error at or near "FRM"

Corrected Query:

SELECT * FROM table_name;

In this example, “FRM” should be “FROM”. By carefully examining the query and comparing it with the correct SQL syntax, you can usually identify and correct the error. If you’re unsure about the correct syntax, consulting the PostgreSQL documentation or SQL reference material can be very helpful.

Leave a Comment