No field name in TABLE_MAP_EVENT?

[e7868a]

Hi.

This is not a problem about 'mysql-binlog-connector-java'.

I just find out that there is no field name in TableMapEventData. how can i regenerate the SQL from WRITE_ROWS,UPDATE_ROWS,DELETE_ROWS.or there is other method to update slave mysql database?

Thanks for help.

[shyiko]

Hi Jian,

What do you mean by "field name"?

It's not possible to "regenerate the SQL from WRITE_ROWS,UPDATE_ROWS,DELETE_ROWS". If you need to know original SQL you must either use SBR (binlog_format=STATEMENT) or turn on binlog_rows_query_log_events (available starting from MySQL 5.6.2). In case of the latter you would also have to add custom RowsQuery event data deserializer.

[rtreffer]

Fields (SQL columns) are referenced by position within the table and not name.

CREATE TABLE a ( b BIGINT, c VARCHAR(64) );
INSERT INTO a VALUES (3, '?');

This will create a write row event for table a and it will contain the columns 0 and 1. (I'm not sure if it's 0 or 1 based atm).

To reconstruct field names you'd have to get the schema of the master first.

[shyiko]

Thanks, Rene.

Jian, to get the list of columns you could use something similar to:

Connection connection = ...
DatabaseMetaData metaData = connection.getMetaData();
ResultSet tableResultSet = metaData.getTables(null, "public", null, new String[]{"TABLE"});
try {
    while (tableResultSet.next()) {
        String tableName = tableResultSet.getString("TABLE_NAME");
        ResultSet columnResultSet = metaData.getColumns(null, "public", tableName, null);
        try {
            while (columnResultSet.next()) {
                String columnName = columnResultSet.getString("COLUMN_NAME");
                ...
            }
        } finally {
            columnResultSet.close();
        }
    }
} finally {
    tableResultSet.close();
}

[e7868a]

Thanks guys. That helps me a lot. now i get understand.
I will close the Issue Now.:)

[spccold]

this dosen't work when mysql-binlog-connector-java have a large lag, because mysql binlog is old, but metadata is latest

[ahmedahamid]

Column names have been recently added to the binlog in MySQL 8.0.1, subject to some non-default configuration. With PR #251 now checked in, it is possible to read column names if you set binlog_row_metadata to FULL. More details about the newly added metadata is right here.