lib/database.js
var error = require('./utils/error');
var stats = require('./statistical');
var maths = require('./math-trig');
var utils = require('./utils/common');
var evalExpression = require('./utils/criteria-eval');
function compact(array) {
var result = [];
utils.arrayEach(array, function(value) {
if (value) {
result.push(value);
}
});
return result;
}
exports.FINDFIELD = function(database, title) {
var index = null;
utils.arrayEach(database, function(value, i) {
if (value[0] === title) {
index = i;
return false;
}
});
// Return error if the input field title is incorrect
if (index == null) {
return error.value;
}
return index;
};
function findResultIndex(database, criterias) {
var matches = {};
for (var i = 1; i < database[0].length; ++i) {
matches[i] = true;
}
var maxCriteriaLength = criterias[0].length;
for (i = 1; i < criterias.length; ++i) {
if (criterias[i].length > maxCriteriaLength) {
maxCriteriaLength = criterias[i].length;
}
}
for (var k = 1; k < database.length; ++k) {
for (var l = 1; l < database[k].length; ++l) {
var currentCriteriaResult = false;
var hasMatchingCriteria = false;
for (var j = 0; j < criterias.length; ++j) {
var criteria = criterias[j];
if (criteria.length < maxCriteriaLength) {
continue;
}
var criteriaField = criteria[0];
if (database[k][0] !== criteriaField) {
continue;
}
hasMatchingCriteria = true;
for (var p = 1; p < criteria.length; ++p) {
if (!currentCriteriaResult) {
var isWildcard = criteria[p] === void 0 || criteria[p] === '*';
if (isWildcard) {
currentCriteriaResult = true;
} else {
var tokenizedCriteria = evalExpression.parse(criteria[p] + '');
var tokens = [evalExpression.createToken(database[k][l], evalExpression.TOKEN_TYPE_LITERAL)].concat(tokenizedCriteria);
currentCriteriaResult = evalExpression.compute(tokens);
}
}
}
}
if (hasMatchingCriteria) {
matches[l] = matches[l] && currentCriteriaResult;
}
}
}
var result = [];
for (var n = 0; n < database[0].length; ++n) {
if (matches[n]) {
result.push(n - 1);
}
}
return result;
}
// Database functions
exports.DAVERAGE = function(database, field, criteria) {
// Return error if field is not a number and not a string
if (isNaN(field) && (typeof field !== "string")) {
return error.value;
}
var resultIndexes = findResultIndex(database, criteria);
var targetFields = [];
if (typeof field === "string") {
var index = exports.FINDFIELD(database, field);
targetFields = utils.rest(database[index]);
} else {
targetFields = utils.rest(database[field]);
}
var sum = 0;
utils.arrayEach(resultIndexes, function(value) {
sum += targetFields[value];
});
return resultIndexes.length === 0 ? error.div0 : sum / resultIndexes.length;
};
exports.DCOUNT = function(database, field, criteria) {
// Return error if field is not a number and not a string
if (isNaN(field) && (typeof field !== "string")) {
return error.value;
}
var resultIndexes = findResultIndex(database, criteria);
var targetFields = [];
if (typeof field === "string") {
var index = exports.FINDFIELD(database, field);
targetFields = utils.rest(database[index]);
} else {
targetFields = utils.rest(database[field]);
}
var targetValues = [];
utils.arrayEach(resultIndexes, function(value) {
targetValues.push(targetFields[value]);
});
return stats.COUNT(targetValues);
};
exports.DCOUNTA = function(database, field, criteria) {
// Return error if field is not a number and not a string
if (isNaN(field) && (typeof field !== "string")) {
return error.value;
}
var resultIndexes = findResultIndex(database, criteria);
var targetFields = [];
if (typeof field === "string") {
var index = exports.FINDFIELD(database, field);
targetFields = utils.rest(database[index]);
} else {
targetFields = utils.rest(database[field]);
}
var targetValues = [];
utils.arrayEach(resultIndexes, function(value) {
targetValues.push(targetFields[value]);
});
return stats.COUNTA(targetValues);
};
exports.DGET = function(database, field, criteria) {
// Return error if field is not a number and not a string
if (isNaN(field) && (typeof field !== "string")) {
return error.value;
}
var resultIndexes = findResultIndex(database, criteria);
var targetFields = [];
if (typeof field === "string") {
var index = exports.FINDFIELD(database, field);
targetFields = utils.rest(database[index]);
} else {
targetFields = utils.rest(database[field]);
}
// Return error if no record meets the criteria
if (resultIndexes.length === 0) {
return error.value;
}
// Returns the #NUM! error value because more than one record meets the
// criteria
if (resultIndexes.length > 1) {
return error.num;
}
return targetFields[resultIndexes[0]];
};
exports.DMAX = function(database, field, criteria) {
// Return error if field is not a number and not a string
if (isNaN(field) && (typeof field !== "string")) {
return error.value;
}
var resultIndexes = findResultIndex(database, criteria);
var targetFields = [];
if (typeof field === "string") {
var index = exports.FINDFIELD(database, field);
targetFields = utils.rest(database[index]);
} else {
targetFields = utils.rest(database[field]);
}
var maxValue = targetFields[resultIndexes[0]];
utils.arrayEach(resultIndexes, function(value) {
if (maxValue < targetFields[value]) {
maxValue = targetFields[value];
}
});
return maxValue;
};
exports.DMIN = function(database, field, criteria) {
// Return error if field is not a number and not a string
if (isNaN(field) && (typeof field !== "string")) {
return error.value;
}
var resultIndexes = findResultIndex(database, criteria);
var targetFields = [];
if (typeof field === "string") {
var index = exports.FINDFIELD(database, field);
targetFields = utils.rest(database[index]);
} else {
targetFields = utils.rest(database[field]);
}
var minValue = targetFields[resultIndexes[0]];
utils.arrayEach(resultIndexes, function(value) {
if (minValue > targetFields[value]) {
minValue = targetFields[value];
}
});
return minValue;
};
exports.DPRODUCT = function(database, field, criteria) {
// Return error if field is not a number and not a string
if (isNaN(field) && (typeof field !== "string")) {
return error.value;
}
var resultIndexes = findResultIndex(database, criteria);
var targetFields = [];
if (typeof field === "string") {
var index = exports.FINDFIELD(database, field);
targetFields = utils.rest(database[index]);
} else {
targetFields = utils.rest(database[field]);
}
var targetValues = [];
utils.arrayEach(resultIndexes, function(value) {
targetValues.push(targetFields[value]);
});
targetValues = compact(targetValues);
var result = 1;
utils.arrayEach(targetValues, function(value) {
result *= value;
});
return result;
};
exports.DSTDEV = function(database, field, criteria) {
// Return error if field is not a number and not a string
if (isNaN(field) && (typeof field !== "string")) {
return error.value;
}
var resultIndexes = findResultIndex(database, criteria);
var targetFields = [];
if (typeof field === "string") {
var index = exports.FINDFIELD(database, field);
targetFields = utils.rest(database[index]);
} else {
targetFields = utils.rest(database[field]);
}
var targetValues = [];
utils.arrayEach(resultIndexes, function(value) {
targetValues.push(targetFields[value]);
});
targetValues = compact(targetValues);
return stats.STDEV.S(targetValues);
};
exports.DSTDEVP = function(database, field, criteria) {
// Return error if field is not a number and not a string
if (isNaN(field) && (typeof field !== "string")) {
return error.value;
}
var resultIndexes = findResultIndex(database, criteria);
var targetFields = [];
if (typeof field === "string") {
var index = exports.FINDFIELD(database, field);
targetFields = utils.rest(database[index]);
} else {
targetFields = utils.rest(database[field]);
}
var targetValues = [];
utils.arrayEach(resultIndexes, function(value) {
targetValues.push(targetFields[value]);
});
targetValues = compact(targetValues);
return stats.STDEV.P(targetValues);
};
exports.DSUM = function(database, field, criteria) {
// Return error if field is not a number and not a string
if (isNaN(field) && (typeof field !== "string")) {
return error.value;
}
var resultIndexes = findResultIndex(database, criteria);
var targetFields = [];
if (typeof field === "string") {
var index = exports.FINDFIELD(database, field);
targetFields = utils.rest(database[index]);
} else {
targetFields = utils.rest(database[field]);
}
var targetValues = [];
utils.arrayEach(resultIndexes, function(value) {
targetValues.push(targetFields[value]);
});
return maths.SUM(targetValues);
};
exports.DVAR = function(database, field, criteria) {
// Return error if field is not a number and not a string
if (isNaN(field) && (typeof field !== "string")) {
return error.value;
}
var resultIndexes = findResultIndex(database, criteria);
var targetFields = [];
if (typeof field === "string") {
var index = exports.FINDFIELD(database, field);
targetFields = utils.rest(database[index]);
} else {
targetFields = utils.rest(database[field]);
}
var targetValues = [];
utils.arrayEach(resultIndexes, function(value) {
targetValues.push(targetFields[value]);
});
return stats.VAR.S(targetValues);
};
exports.DVARP = function(database, field, criteria) {
// Return error if field is not a number and not a string
if (isNaN(field) && (typeof field !== "string")) {
return error.value;
}
var resultIndexes = findResultIndex(database, criteria);
var targetFields = [];
if (typeof field === "string") {
var index = exports.FINDFIELD(database, field);
targetFields = utils.rest(database[index]);
} else {
targetFields = utils.rest(database[field]);
}
var targetValues = [];
utils.arrayEach(resultIndexes, function(value) {
targetValues.push(targetFields[value]);
});
return stats.VAR.P(targetValues);
};