public static boolean supportsConvert()

in src/main/core-api/java/com/mysql/cj/MysqlType.java [708:867]
119 lines of code
82 McCabe index (conditional complexity)

    public static boolean supportsConvert(int fromType, int toType) {
        // TODO use MysqlTypes here ?

        switch (fromType) {
            /*
             * The char/binary types can be converted to pretty much anything.
             */
            case java.sql.Types.CHAR:
            case java.sql.Types.VARCHAR:
            case java.sql.Types.LONGVARCHAR:
            case java.sql.Types.BINARY:
            case java.sql.Types.VARBINARY:
            case java.sql.Types.LONGVARBINARY:

                switch (toType) {
                    case java.sql.Types.DECIMAL:
                    case java.sql.Types.NUMERIC:
                    case java.sql.Types.REAL:
                    case java.sql.Types.TINYINT:
                    case java.sql.Types.SMALLINT:
                    case java.sql.Types.INTEGER:
                    case java.sql.Types.BIGINT:
                    case java.sql.Types.FLOAT:
                    case java.sql.Types.DOUBLE:
                    case java.sql.Types.CHAR:
                    case java.sql.Types.VARCHAR:
                    case java.sql.Types.LONGVARCHAR:
                    case java.sql.Types.BINARY:
                    case java.sql.Types.VARBINARY:
                    case java.sql.Types.LONGVARBINARY:
                    case java.sql.Types.OTHER:
                    case java.sql.Types.DATE:
                    case java.sql.Types.TIME:
                    case java.sql.Types.TIMESTAMP:
                        return true;

                    default:
                        return false;
                }

                /*
                 * We don't handle the BIT type yet.
                 */
            case java.sql.Types.BIT:
                return false;

            /*
             * The numeric types. Basically they can convert among themselves, and with char/binary types.
             */
            case java.sql.Types.DECIMAL:
            case java.sql.Types.NUMERIC:
            case java.sql.Types.REAL:
            case java.sql.Types.TINYINT:
            case java.sql.Types.SMALLINT:
            case java.sql.Types.INTEGER:
            case java.sql.Types.BIGINT:
            case java.sql.Types.FLOAT:
            case java.sql.Types.DOUBLE:

                switch (toType) {
                    case java.sql.Types.DECIMAL:
                    case java.sql.Types.NUMERIC:
                    case java.sql.Types.REAL:
                    case java.sql.Types.TINYINT:
                    case java.sql.Types.SMALLINT:
                    case java.sql.Types.INTEGER:
                    case java.sql.Types.BIGINT:
                    case java.sql.Types.FLOAT:
                    case java.sql.Types.DOUBLE:
                    case java.sql.Types.CHAR:
                    case java.sql.Types.VARCHAR:
                    case java.sql.Types.LONGVARCHAR:
                    case java.sql.Types.BINARY:
                    case java.sql.Types.VARBINARY:
                    case java.sql.Types.LONGVARBINARY:
                        return true;

                    default:
                        return false;
                }

                /* MySQL doesn't support a NULL type. */
            case java.sql.Types.NULL:
                return false;

            /*
             * With this driver, this will always be a serialized object, so the char/binary types will work.
             */
            case java.sql.Types.OTHER:

                switch (toType) {
                    case java.sql.Types.CHAR:
                    case java.sql.Types.VARCHAR:
                    case java.sql.Types.LONGVARCHAR:
                    case java.sql.Types.BINARY:
                    case java.sql.Types.VARBINARY:
                    case java.sql.Types.LONGVARBINARY:
                        return true;

                    default:
                        return false;
                }

                /* Dates can be converted to char/binary types. */
            case java.sql.Types.DATE:

                switch (toType) {
                    case java.sql.Types.CHAR:
                    case java.sql.Types.VARCHAR:
                    case java.sql.Types.LONGVARCHAR:
                    case java.sql.Types.BINARY:
                    case java.sql.Types.VARBINARY:
                    case java.sql.Types.LONGVARBINARY:
                        return true;

                    default:
                        return false;
                }

                /* Time can be converted to char/binary types */
            case java.sql.Types.TIME:

                switch (toType) {
                    case java.sql.Types.CHAR:
                    case java.sql.Types.VARCHAR:
                    case java.sql.Types.LONGVARCHAR:
                    case java.sql.Types.BINARY:
                    case java.sql.Types.VARBINARY:
                    case java.sql.Types.LONGVARBINARY:
                        return true;

                    default:
                        return false;
                }

                /*
                 * Timestamp can be converted to char/binary types and date/time types (with loss of precision).
                 */
            case java.sql.Types.TIMESTAMP:

                switch (toType) {
                    case java.sql.Types.CHAR:
                    case java.sql.Types.VARCHAR:
                    case java.sql.Types.LONGVARCHAR:
                    case java.sql.Types.BINARY:
                    case java.sql.Types.VARBINARY:
                    case java.sql.Types.LONGVARBINARY:
                    case java.sql.Types.TIME:
                    case java.sql.Types.DATE:
                        return true;

                    default:
                        return false;
                }

                /* We shouldn't get here! */
            default:
                return false; // not sure
        }
    }