igo/src/db/Sql.js

Igo is a Node.js Web Framework based on Express

const _       = require('lodash');


//
var Sql = function(query) {

  // SELECT SQL
  this.selectSQL = function() {

    let sql       = 'SELECT ';
    const params  = [];

    if (query.distinct) {
      sql += 'DISTINCT `' + query.distinct.join('`,`') + '` ';
    } else if (query.select) {
      sql += query.select + ' ';
    } else {
      sql += '`' + query.table + '`.* ';
    }
    // } else if (!_.isEmpty(query.group)) {
    //   sql += 'COUNT(*) AS `count`, ' + query.group.join(', ') + ' ';
    // } else {
    //   sql += '* ';
    // }

    // from
    sql += 'FROM `' + query.table + '` ';

    // where
    sql += this.whereSQL(params);

    // group
    sql += this.groupSQL();

    // order by
    sql += this.orderSQL();


    // limit
    if (query.limit) {
      sql += 'LIMIT ?, ? ';
      params.push(query.offset || 0);
      params.push(query.limit);
    }

    var ret = {
      sql: sql.trim(),
      params: params
    };
    // console.dir(ret);
    return ret;
  };

  // COUNT SQL
  this.countSQL = function() {
    // select
    var sql = 'SELECT COUNT(0) as `count` ';
    var params = [];

    // from
    sql += 'FROM `' + query.table + '` ';

    // where
    sql += this.whereSQL(params);

    var ret = {
      sql: sql.trim(),
      params: params
    };
    // console.dir(ret);
    return ret;
  };

  //
  this.whereSQL = function(params) {
    var sqlwhere = [];
    _.forEach(query.where, function(where) {
      if (_.isArray(where)) {
        sqlwhere.push(where[0] + ' ');
        if (_.isArray(where[1])) {
          Array.prototype.push.apply(params, where[1]);
        } else {
          params.push(where[1]);
        }
      } else if (_.isString(where)) {
        sqlwhere.push(where + ' ');
      } else {
        _.forEach(where, function(value, key) {
          if (value === null) {
            sqlwhere.push('`' + key + '` IS NULL ');
          } else if (_.isArray(value) && value.length === 0) {
            // where in empty array --> FALSE
            sqlwhere.push('FALSE ');
          } else if (_.isArray(value)) {
            sqlwhere.push('`' + key + '` IN (?) ');
            params.push(value);
          } else {
            sqlwhere.push('`' + key + '`=? ');
            params.push(value);
          }
        });
      }
    });
    if (sqlwhere.length) {
      return 'WHERE ' + sqlwhere.join('AND ');
    }
    return '';
  };

  // INSERT SQL
  this.insertSQL = function() {

    // insert into
    var sql = 'INSERT INTO `' + query.table + '`';

    // columns
    var columns = [], values = [], params = [];
    _.forEach(query.values, function(value, key) {
      columns.push('`' + key + '`');
      values.push('?');
      params.push(value);
    });

    sql += '(' + columns.join(',') + ') ';
    sql += 'VALUES(' + values.join(',') + ')';

    var ret = {
      sql: sql,
      params: params
    };
    // console.dir(ret);
    return ret;
  };

  // UPDATE SQL
  this.updateSQL = function() {

    // update set
    var sql = 'UPDATE `' + query.table + '` SET ';

    // columns
    var columns = [], values = [], params = [];
    _.forEach(query.values, function(value, key) {
      columns.push('`' + key + '`=?');
      params.push(value);
    });

    sql += columns.join(', ') + ' ';

    sql += this.whereSQL(params);

    var ret = {
      sql: sql,
      params: params
    };
    return ret;
  };

  // DELETE SQL
  this.deleteSQL = function() {

    // delete
    var sql = 'DELETE FROM `' + query.table + '` ';

    // columns
    var params = [];
    sql += this.whereSQL(params);

    var ret = {
      sql: sql,
      params: params
    };
    return ret;
  };

  // ORDER BY SQL
  this.orderSQL = function() {

    if (!query.order || !query.order.length) {
      return '';
    }

    var sql = 'ORDER BY ' + query.order.join(', ') + ' ';

    return sql;
  };


  // GROUP BY SQL
  this.groupSQL = function() {
    if (_.isEmpty(query.group )) {
      return '';
    }

    var sql = 'GROUP BY ' + query.group.join(', ') + ' ';
    return sql;
  };
};

module.exports = Sql;