即使没有插入空值，{primary key}列也不会出现NULL错误

Question

我注意到，当我尝试将记录插入“主键”列中时，即使我要为该列输入的值不为null，也会遇到NULL not allowed for column错误。有谁知道为什么会这样！？下面是我的PreparedStatement.toString（）以及堆栈跟踪。非常感谢您的帮助！

PreparedStatement = 'prep0: MERGE INTO results (rank,lastname,firstname,country,time) VALUES (?,?,?,?,?); {1: '1', 2: 'smith', 3: 'john', 4: 'USA', 5: '2:30'}'...
Exception in thread "main" org.h2.jdbc.JdbcSQLException: NULL not allowed for column "FIRSTNAME"; SQL statement:
MERGE INTO results (rank,lastname,firstname,country,time) VALUES (?,?,?,?,?); [23502-193]`

    at org.h2.message.DbException.getJdbcSQLException(DbException.java:345)
    at org.h2.message.DbException.get(DbException.java:179)
    at org.h2.message.DbException.get(DbException.java:155)
    at org.h2.table.Column.validateConvertUpdateSequence(Column.java:311)
    at org.h2.table.Table.validateConvertUpdateSequence(Table.java:784)
    at org.h2.command.dml.Merge.merge(Merge.java:157)
    at org.h2.command.dml.Merge.update(Merge.java:106)
    at org.h2.command.CommandContainer.update(CommandContainer.java:98)
    at org.h2.command.Command.executeUpdate(Command.java:258)
    at org.h2.jdbc.JdbcPreparedStatement.execute(JdbcPreparedStatement.java:201)
    at Table.merge(Table.java:272)
    at CSV.writeToDatabase(CSV.java:643)
    at CLI.combineData(CLI.java:152)
    at CLI.run(CLI.java:48)
    at CLI.main(CLI.java:163)`

这是创建查询的方法：

    void merge( Map<String,Object> values ) throws SQLException
    {
        if ( values.isEmpty() )
        {
            System.out.println("No data in values map..."); 
            return;
        }
        query = new StringBuilder("MERGE INTO " + name + " (");

        List<String> attrs = new ArrayList<>(values.keySet());

        for ( int a=0; a < attrs.size(); a++ ) 
        {
            query.append( a > 0 ? "," : "" ).append( attrs.get(a).toLowerCase() ); 
        }
        query.append(") VALUES (");

        for ( int a=0; a < attrs.size(); a++ )
        {
            query.append( a > 0 ? ",?" : "?" );
        }
        query.append(");");

        PreparedStatement ps = db.conn.prepareStatement(query.toString());

        for ( int v=0; v < attrs.size(); v++ )
        {
            Object value = values.get(attrs.get(v));

            if ( value == null )
            {
                ps.setString(v+1, null);
            }
            else if ( value instanceof String || value instanceof Date)
            {
                ps.setString(v+1, value.toString() );
            }
            else if ( value instanceof Integer )
            {
                ps.setInt(v+1, (Integer) value);
            }
            else if ( value instanceof Double )
            {
                ps.setDouble(v+1, (Double) value);
            }
            else 
            {
                ps.setString(v+1, null);
            }
        }
        System.out.println("PreparedStatement = '" + ps.toString() + "'...");
        ps.execute();
    }