Message-ID: <gh-pgjdbc-pgjdbc-3659@github.com>
From: "SophiahHo (@SophiahHo)" <noreply+SophiahHo@github.com>
To: "pgjdbc/pgjdbc" <noreply+pgjdbc-pgjdbc@github.com>
Date: Thu, 12 Jun 2025 20:16:05 +0000
Subject: [pgjdbc/pgjdbc] issue #3659: NullPointerException in getTables getMetaData: Off-by-one difference between ResultSetMetaData size and getColumnCount()
List-Id: <gh-pgjdbc-pgjdbc.github.com>
X-GitHub-Author-Id: 182134868
X-GitHub-Author-Login: SophiahHo
X-GitHub-Issue: 3659
X-GitHub-Repo: pgjdbc/pgjdbc
X-GitHub-State: closed
X-GitHub-Type: issue
X-GitHub-Url: https://github.com/pgjdbc/pgjdbc/issues/3659
Content-Type: text/plain; charset=utf-8

**Describe the issue**
NullPointerException due to off-by-one difference between ResultSetMetaData size and getColumnCount() in getTables' getMetaData.

**Driver Version?** 
42.7.7

**Java Version?**
17

**To Reproduce**
Steps to reproduce the behaviour:

```java
        ResultSet rs = connection.getMetaData().getTables(
                "WrongCatalog", // catalog
                null, // schemaPattern
                null, // tableNamePattern
                null // types
        );
        ResultSetMetaData rsmd = rs.getMetaData();
        for (int col = 1; col <= rsmd.getColumnCount(); col++){
            System.out.println(col + ". " + rsmd.getColumnLabel(col));
        }
```

Result:
```
java.lang.NullPointerException: Cannot invoke "org.postgresql.core.Field.getColumnLabel()" because "field" is null
```

**Expected behaviour**
No exception