Message-ID: <gh-pgjdbc-pgjdbc-3729@github.com>
From: "Chitrae92 (@Chitrae92)" <noreply+Chitrae92@github.com>
To: "pgjdbc/pgjdbc" <noreply+pgjdbc-pgjdbc@github.com>
Date: Fri, 18 Jul 2025 01:31:15 +0000
Subject: [pgjdbc/pgjdbc] issue #3729: PgDatabaseMetaData.getColumns returns duplicate columnNames
List-Id: <gh-pgjdbc-pgjdbc.github.com>
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X-GitHub-Issue: 3729
X-GitHub-Repo: pgjdbc/pgjdbc
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X-GitHub-Url: https://github.com/pgjdbc/pgjdbc/issues/3729
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Postgres jdbc version - **42.6.1**
Java version - 17

When we execute code to retrieve column names for a table with schema name having _ in them and there exists similar table in another schema, we currently get duplicate columns due to the like clause used in getColumns

Example:
**Schema Name:** test_ **Table Name:** tableA *Column Names* c1, c2
 **Schema Name:** test1 **Table Name:** tableA *Column Names* c1, c2

PgDatabaseMetaData.getColumns function ends up returning c1, c2, c1, c2 when getting the column Names for  test_.tableA since the LIKE clause satisfies for both the schema names. Is this expected by design? Should we not escape _ in schema or table names instead of treating them as wild characters.

    if (schemaPattern != null && !schemaPattern.isEmpty()) {
      sql += " AND n.nspname LIKE " + escapeQuotes(schemaPattern);
    }
    if (tableNamePattern != null && !tableNamePattern.isEmpty()) {
      sql += " AND c.relname LIKE " + escapeQuotes(tableNamePattern);
    }