This gist showcases the functionality of Oracle data modeler for creating tables programatically

oracle-data-modeler-rm.js

// How to access Relational models globally and create schemas and tables within it

var console = {
    log: function(msg) {
        model.getAppView().logMessage(msg);
    }
}

var RELATIONAL_MODEL = "test";
var SCHEMA = "test";
var TABLE = "test";

var relational_model = model.design.relationalDesigns.getByName(RELATIONAL_MODEL);
if (!relational_model){
  relational_model = model.design.addRelationalDesign();
  relational_model.setName(RELATIONAL_MODEL);
}
var schemas = relational_model.getSchemaObjectSet();
var schema = schemas.getByName(SCHEMA);
if (!schema) {
  schema = schemas.createSchemaObject(SCHEMA);
  schema.setName(SCHEMA);
}

var table = relational_model.getTableSet().getByName(TABLE);

oracle-data-modeler.js

// Old habits die hard
var console = {
    log: function(msg) {
        model.getAppView().logMessage(msg);
    }
}

// Table has to exist for the process to work
var TABLE = "TEST";
// [name, type, mandatory, description]
var TABLE_DEFINITION = [
    ['f_decimal', 'DECIMAL(16,2)', true, 'Decimal field'],
    ['f_integer', 'INT(11)', false, 'Integer field'],
    ['f_char', 'CHAR(1)', false, 'Char field'],
    ['f_varchar', 'VARCHAR(10)', false, 'Varchar field'],
    ['f_datetime', 'DATETIME', false, 'Date field'],
];

var tables = model.getTableSet().toArray();

var datatypes = model.getDesign().getLogicalDatatypeSet().toArray();

function getDatatype(name) {
    for (var x in datatypes) {
        var datatype = datatypes[x];
        if (datatype.getName().toUpperCase() === name.toUpperCase()) {
            return datatype;
        }
    }
}
// Datatypes to be transformed into Oracle datatypes
var DATATYPES = {
    CHAR: getDatatype("CHAR"),
    DECIMAL: getDatatype("DECIMAL"),
    DATE: getDatatype("DATE"),
    DATETIME: getDatatype("DATETIME"),
    INTEGER: getDatatype("INTEGER"),
    VARCHAR: getDatatype("VARCHAR"),
};

function getMatchingString(str1, str2) {
    var matches = "";
    for (var x = 0; x < str1.length; x++) {
        if (str1[x] === str2[x]) {
            matches += str1[x];
        } else {
            break;
        }
    }

    return matches;
}

function matchDatatype(raw_match) {
    var clean_match = raw_match.toUpperCase().trim();
    var datatype = {
        type: undefined,
        precision: undefined,
        scale: undefined,
        size: undefined,
    }

    if (clean_match.startsWith("CHAR")) {
        var length = clean_match.match(/\(([^)]+)\)/)[1].trim();
        if (!isNaN(length)) {
            datatype.type = DATATYPES.CHAR;
            datatype.size = length;
        }
    }

    if (clean_match === "DATE") {
        datatype.type = DATATYPES.DATE;
    }

    if (clean_match === "DATETIME") {
        datatype.type = DATATYPES.DATETIME;
    }

    if (clean_match.startsWith("DECIMAL")) {
        var precision = clean_match.match(/\((\d+),\s*(\d+)\)/)[1];
        var scale = clean_match.match(/\((\d+),\s*(\d+)\)/)[2];
        if (!isNaN(Number(precision)) && !isNaN(Number(scale))) {
            datatype.type = DATATYPES.DECIMAL;
            datatype.precision = precision;
            datatype.scale = scale;
        }
    }

    if (clean_match === "INT(11)" || clean_match === "INT (11)") {
        datatype.type = DATATYPES.INTEGER;
    }

    if (clean_match.startsWith("VARCHAR")) {
        var length = clean_match.match(/\(([^)]+)\)/)[1].trim();
        if (!isNaN(length)) {
            datatype.type = DATATYPES.VARCHAR;
            datatype.size = length;
        }
    }

    if (datatype.type === undefined) {
        throw new Error("Could not find match for type " + clean_match);
    }

    return datatype;
}

for (var x = 0; x < tables.length; x++) {
    var table = tables[x];
    if (table.getName() === TABLE) {
        var columns = table.getElements();
        // Delete existing columns
        for (var y = 0; y < columns.length; y++) {
            var column = columns[y];
            column.remove();
        }

        for (var z in TABLE_DEFINITION) {
            var column = table.createColumn();
            var name = TABLE_DEFINITION[z][0];
            var type = TABLE_DEFINITION[z][1];
            var mandatory = TABLE_DEFINITION[z][2];
            var description = TABLE_DEFINITION[z][3];

            var datatype = matchDatatype(type);

            column.setName(name);
            // Set type to logical
            column.setUse(1);
            column.setLogicalDatatype(datatype.type);
            column.setDataTypePrecision(datatype.precision);
            column.setDataTypeScale(datatype.scale);
            column.setDataTypeSize(datatype.size);
            column.setMandatory(mandatory);
            column.setCommentInRDBMS(description);
				}
    }
}