How Do I Resolve the 'SQL column reference 'id' is ambiguous' Error?

Resolving the Ambiguous "id" Column in SQL Queries

The error "SQL column reference "id" is ambiguous" arises when your SQL query includes a column named "id" present in multiple tables. The database cannot determine which "id" column you intend to use.

Here's an illustrative example:

<code class="language-sql">SELECT (id, name)
FROM v_groups vg
INNER JOIN people2v_groups p2vg ON vg.id = p2vg.v_group_id
WHERE p2vg.people_id = 0;</code>

In this query, both v_groups (aliased as vg) and people2v_groups (aliased as p2vg) contain an "id" column. The solution is to explicitly qualify the column name with its table alias:

<code class="language-sql">SELECT (vg.id, name)
FROM v_groups vg
INNER JOIN people2v_groups p2vg ON vg.id = p2vg.v_group_id
WHERE p2vg.people_id = 0;</code>

By using vg.id, you clearly specify that you're referencing the "id" column from the v_groups table, eliminating the ambiguity and preventing the error. This technique ensures the query correctly identifies the intended column.

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