A developer runs a SQL query against a database and receives the error shown. Which of the following actions should the developer take first to resolve the issue?
Verifying the schema will show the correct column names.
Why this answer
The error indicates that the column 'user_id' does not exist in the 'users' table. The most logical first step is to check the table definition to confirm the actual column names, as the developer may have misspelled the column name or used the wrong case. This avoids unnecessary destructive actions like dropping the table or making incorrect assumptions about case sensitivity.
Exam trap
The trap here is that candidates may assume the error is due to case sensitivity or syntax issues, when in fact the most common cause is a simple typo or mismatch in column names, which is best resolved by checking the table definition first.
How to eliminate wrong answers
Option B is wrong because dropping and recreating the table is a destructive action that should only be taken after verifying the schema and understanding the root cause; it also risks data loss. Option C is wrong because SQL column names are case-insensitive by default in most database systems (e.g., MySQL, PostgreSQL) unless the server or table is configured with case-sensitive identifiers, so changing case is unlikely to fix the issue and may introduce new errors. Option D is wrong because adding quotes around the table name would not resolve a missing column error; quotes are used for identifiers with special characters or reserved words, not for correcting column name mismatches.