Support column type for ResultSet

[ruixuel]

Version

• vert.x core: 3.5.1
• vert.x jdbc-client: 3.5.1
• jdbc driver: postgres
• RDBMS: postgres

Context

Hi, I am wondering if it is possible to add column type in io.vertx.ext.sql.ResultSet. I need column data type from java.sql.ResultSetMetaData and convert the query result to apache arrow according to the column data type.

In io.vertx.ext.jdbc.impl.actions.JDBCStatementHelper.java, io.vertx.ext.sql.ResultSet already get the column names from ResultSetMetaData. So it would be nice if ColumnType could also be added to ResultSet. ColumnType can be get from ResultSetMetaData by getColumnType(int) method.(https://docs.oracle.com/javase/7/docs/api/java/sql/ResultSetMetaData.html#getColumnType(int))

public io.vertx.ext.sql.ResultSet asList(ResultSet rs) throws SQLException { List columnNames = new ArrayList<>(); ResultSetMetaData metaData = rs.getMetaData(); int cols = metaData.getColumnCount(); for (int i = 1; i <= cols; i++) { columnNames.add(metaData.getColumnLabel(i)); //Add column types here? } ..... return new io.vertx.ext.sql.ResultSet(columnNames, results, null); }

If it is not possible to do that, is there any way that I can do asynchronous sql query and get the column type from the query result?

Thank you!

[deeper-thought]

Just use reflection to get it.

Field field = sqlRowStream.getClass().getDeclaredField("metaData"); field.setAccessible(true); ResultSetMetaData metaData = (ResultSetMetaData) field.get(sqlRowStream);

int cols = metaData.getColumnCount(); for (int i = 1; i <= cols; i++) { // metaData.getColumnTypeName(i) }